Tag Archives: orthoses

Navicular dislocation and orthotic management: A case study

by Joshua Young BSc.(Hons), MBAPO Orthotist1*

The Foot and Ankle Online Journal 11 (3): 2

Navicular dislocation is a rare injury, typically managed by surgical fixation. This case study presents the results of conservative management of navicular dislocation, using a custom foot orthosis, combined with a removable walker boot. At 6 week review the numeric pain rating scale (NRS-11) score was reduced from 8/10 to 3/10. A foot orthosis combined with a removable walker boot may reduce pain in the short term in non-operable navicular dislocation more successfully than a walker boot alone.

Keywords: navicular, navicular dislocation, orthoses, orthotics

ISSN 1941-6806
doi: 10.3827/faoj.2018.1103.0002

1 – Roehampton Rehabilitation Centre, Queen Mary’s Hospital. St George’s University Hospitals NHS Foundation Trust; Opcare, Oxfordshire, UK.
* – Corresponding author: Joshua.Young@stgeorges.nhs.uk


Dislocation of the navicular without fracture is a rare injury [1-3]. A 2015 case study by Singh and colleagues found 16 previously reported cases in the literature [2].  A further case study was published in 2016 [1]. Two other published cases were not identified which gives a total estimate of 20 published cases in the literature to date [4,5].

The mechanics of injury are commonly described as involving pronation, with abduction of the forefoot [6]. Davis and colleagues describe a transient midtarsal dislocation which allows the navicular to dislocate [3]. The navicular may displace in a plantar or dorsal direction, depending on the nature of the injury.  Dhillon and Nagi argue that the injury is never truly an isolated injury as disruption to both the medial and lateral columns of the foot is necessary [6].

Surgical management is usually recommended, typically with temporary Kirschner wire fixation, although other means of fixation may be used [1-3].  Custom foot orthoses have been suggested as a possible treatment option for surgically corrected cases of navicular dislocation which remain painful  however there are no reported cases of purely conservative management of navicular dislocation of which the author is aware [1]. This case report presents a navicular dislocation managed purely conservatively using orthoses due to surgical risk factors which made the subject a poor candidate for surgery.

Case report

A 67-year-old male was referred to see an orthotist in the orthotic service by his orthopedic foot and ankle consultant. The subject had an injury to his left foot 5 months previously sustained during a fall which occurred whilst walking indoors. Initial radiographs and computed tomography scans following the fall show a dislocated navicular and cuboid fracture (Figures 1-4). One month post injury radiographs showed reduced 11 degree calcaneal inclination angle on the left (affected) side compared to 24 degrees on the right, reflecting a reduction in height of the medial longitudinal arch.

Figure 1 Dislocated navicular resting inferior to the sustentaculum tali.

Figure 2 Dislocated navicular resting inferior to the sustentaculum tali.

Figure 3 Cuboid fracture.

Figure 4 Three dimensional CT reconstruction showing dislocated navicular.

A significant factor in the injury was the subject’s body weight which at 2 months following the injury was 161kg (Body Mass Index 50). At the time of assessment in orthotic clinic 3 months later, this had increased to 189kg (Body Mass Index 56). The increased body weight will have increased the ground reaction forces experienced by the foot, and the resultant internal stresses on tissues such as ligamentous tissue which normally help to maintain joint congruency [7,8].

Following two orthopedic opinions, and assessment in a high risk anesthetic clinic, it was agreed to avoid surgery due to the high risk of mortality. It was observed that the talar head was now articulating with the medial cuneiform, forming a pseudo joint.

At presentation in orthotic clinic the subject reported pain as the primary concern. His walking was very limited to short distances indoors, wearing a removable walker boot (Aircast Airselect, Donjoy). He reported pain at an intensity of up to 8 out of 10 (numeric rating scale, NRS-11). A custom ankle foot orthosis (AFO) was considered to limit painful movement within the foot, however this was decided to not be feasible as the subject would struggle to apply or remove this independently [9]. A custom foot orthosis (FO) was prescribed to wear inside the walker boot. The mechanical aim of this was to apply forces to the medial longitudinal arch in an attempt to modify compressive stresses assumed to be occurring at the midfoot and talo-cuneiform pseudo-joint, and tensile stresses assumed to be occurring in soft tissues at the plantar foot [9]. The FO was made from an imprint of the foot in a foam impression box using a computer aided design and manufacture (CAD-CAM) system (Paromed, Neubeuern, Germany). The FO was manufactured using 70 shore material at the heel to midfoot, and softer 50 shore material from the midfoot to the forefoot. A soft 3.2mm grey poron polyurethane foam cover (Algeos, Liverpool, UK) was added. The shape of the FO is demonstrated by the modeling images (Figure 5a-d).

FAOJ_11.3.2 (1)

Figure 5 Custom foot orthosis, medial view (a), lateral view (b), anterior view (c), dorsoplantar view (d).

At 6 week review the subject reported good compliance with wearing the FO within the walker boot. Using the 11 point numeric pain rating scale (NRS-11), pain intensity during walking was reported to be reduced from 8/10 to 3/10.

Discussion

This case study presents the results of conservative management of an unusual foot injury. A custom FO, combined with a walker boot, reduced pain intensity in the short term. Pain was still present while using the walker boot only. The reported reduction in pain following addition of the FO may imply that the FO was able to modify stresses in the midfoot, even in the presence of very high body weight, in order to be effective. FOs are rarely used for this specific application due to the rarity of the injury, however they may be combined  with walker boots to manage Charcot foot which is also associated with major change of the midfoot architecture. Limitations of this study include a lack of further outcome measures, and possible bias incurred by the treating clinician administering the NRS-11 pain scale. This case study illustrates the possibility that even major changes in the bony structure of the foot, which are symptomatic, may be manageable to some extent conservatively using foot orthoses.

Acknowledgements

The author would like to acknowledge Dominic Nielsen, consultant orthopaedic surgeon, for his comments on the paper.

References

  1. Ansari MAQ. Isolated complete dislocation of the tarsal navicular without fracture: A rare injury. Ci Ji Yi Xue Za Zhi. 2016;28(3):128-131.
  2. Singh VK, Kashyap A, Vargaonkar G, Kumar R. An isolated dorso-medial dislocation of navicular bone: A case report. J Clin Orthop Trauma. 2015;6(1):36-8.
  3. Davis AT, Dann A, Kuldjanov D. Complete medial dislocation of the tarsal navicular without fracture: report of a rare injury. J Foot Ankle Surg. 2013;52(3):393-6.
  4. Hamdi K, Hazem BG, Yadh Z, Faouzi A. Isolated dorsal dislocation of the tarsal naviculum. Indian J Orthop. 2015;49(6):676-9.
  5. Dias MB, Zagonel B, Dickel MS, Talheimer JA, Argenton IS, et al. Isolated dislocation of the tarsal navicular without fracture: Case report. Trauma Cases. 2016,Rev 2:045
  6. Dhillon MS, Nagi ON. Total dislocations of the navicular: are they ever isolated injuries?. J Bone Joint Surg Br. 1999;81(5):881-5.
  7. Browning RC, Kram R. Effects of obesity on the biomechanics of walking at different speeds. Med Sci Sports Exerc. 2007;39(9):1632-41.
  8. Pamukoff DN, Lewek MD, Blackburn JT. Greater vertical loading rate in obese compared to normal weight young adults. Clin Biomech (Bristol, Avon). 2016;33:61-65.
  9. International standards organization. ISO 8549-3, Prosthetics and orthotics – Vocabulary – Part 3: Terms relating to external orthoses. 1989.

Effects of medial and lateral orthoses on kinetics and tibiocalcaneal kinematics in male runners

by Jonathan Sinclair1*

The Foot and Ankle Online Journal 10 (4): 1

Background: The aim of the current investigation was to examine the effects of foot orthotic devices with a 5° medial and lateral wedge on kinetics and tibiocalcaneal kinematics during the stance phase of running.
Material and methods: Twelve male participants ran over a force platform at 4.0 m/s in three different conditions (5° medial orthotic, 5° lateral orthotic and no-orthotic). Tibiocalcaneal kinematics were collected using an 8 camera motion capture system and axial tibial accelerations were obtained via an accelerometer mounted to the distal tibia. Biomechanical differences between orthotic conditions were examined using one-way repeated measures of analysis of variance (ANOVA).
Results: The results showed that no differences (P>0.05) in kinetics/tibial accelerations were evident between orthotic conditions. However, it was revealed that the medial orthotic significantly (P<0.05) reduced peak ankle eversion and relative tibial internal rotation range of motion (-10.75 & 4.98°) in relation to the lateral (-14.11 & 6.14°) and no-orthotic (-12.37 & 7.47°) conditions.
Conclusions: The findings from this study indicate, therefore, that medial orthoses may be effective in attenuating tibiocalcaneal kinematic risk factors linked to the etiology of chronic pathologies in runners.

Keywords: running, biomechanics, orthoses, kinetics, kinematics

ISSN 1941-6806
doi: 10.3827/faoj.2017.1004.0001

1 – Center for Applied Sport Exercise and Nutritional Sciences, School of Sport and Wellbeing, Faculty of Health & Wellbeing, University of Central Lancashire, Preston, Lancashire, PR1 2HE.
* – Corresponding author: jksinclair@uclan.ac.uk


Distance running is associated with a significant number of physiological and psychological benefits [1]. However, epidemiological analyses have demonstrated that pathologies of a chronic nature are extremely common in both recreational and competitive runners [2] and as many as 80% of runners will experience a chronic injury as a consequence of their training over a one-year period [2].

Given the high incidence of chronic pathologies in runners, a range of strategies have been investigated and implemented in clinical research in an attempt to mitigate the risk of injury in runners. Foot orthoses are very popular devices that are used extensively by runners [3]. It has been proposed that foot orthoses may be able to attenuate the parameters linked to the etiology of injury in runners, thus they have been cited as a mechanism by which injuries can be prophylactically avoided and also retrospectively treated [4]. The majority of research investigating the biomechanical effects of foot orthoses during running has examined either impact loading or rearfoot eversion parameters which have been linked to the etiology of running injuries. Sinclair et al, [5] showed that an off the shelf orthotic device significantly reduced vertical rates of loading and axial tibial accelerations, but did not alter the magnitude of rearfoot eversion. Butler et al, [6] examined three-dimensional (3D) kinematic/ kinetic data alongside axial tibial accelerations during running, using dual-purpose and a rigid orthoses. Their findings revealed that none of the experimental parameters were differed significantly between the different orthotic conditions.  Laughton et al, [7] showed that foot orthoses significantly reduced the loading rate of the vertical ground reaction force but did not significantly influence rearfoot eversion parameters. Dixon, [8] examined the influence of off the shelf foot orthoses placed inside an military boot on kinetic and 3D kinematic parameters during running. The findings from this investigation revealed that the orthotic device significantly reduced the vertical rate of loading, but no alterations in ankle eversion were reported.

Further to this, because the mechanics of the foot alter the kinetics/kinematics of the proximal lower extremity joints, biomechanical control of the foot with in-shoe orthotic wedges has wide-ranging applications for the treatment of a variety chronic lower extremity conditions. Different combinations of wedges or posts have therefore been used in clinical practice/ research to treat a multitude of chronic pathologies [9]. Both valgus (lateral) and varus (medial) orthoses have been proposed as potentially important low-cost devices for the conservative management of chronic pathologies [10].

Lateral orthoses are utilized extensively in order to reduce the loads experienced by the medial tibiofemoral compartment [10]. Lateral orthoses cause the center of pressure to shift medially thereby moving the medial-lateral ground reaction force vector closer to the knee joint center [11]. This serves to reduce the magnitude of the knee adduction moment which is indicative of compressive loading of the medial aspect of the tibiofemoral joint and its progressive degeneration [12]. Kakihana et al, investigated the biomechanical effects of lateral wedge orthoses on knee joint moments during gait in elderly participants with and without knee osteoarthritis [13]. The lateral wedge significantly reduced the knee adduction moment in both groups when compared with no wedge. Butler et al, examined the effects of a laterally wedged foot orthosis on knee mechanics in patients with medial knee osteoarthritis [14]. The laterally wedged orthotic device significantly reduced the peak adduction moment and also the knee adduction excursion from heel strike to peak adduction compared to the non-wedged device. Kakihana et al, examined the kinematic and kinetic effects of a lateral wedge insole on knee joint mechanics during gait in healthy adults [15]. The wedged insole significantly reduced the knee adduction moment during gait in comparison to the no-wedge condition, although no changes in knee kinematics were evident.

The influence of medially oriented foot orthoses has also been frequently explored in biomechanical literature. Boldt et al, examined the effects of medially wedged foot orthoses on knee and hip joint mechanics during running in females with and without patellofemoral pain syndrome [16]. The findings from this study showed that the peak knee adduction moment increased and hip adduction excursion decreased significantly when wearing medially wedged foot orthoses. Sinclair et al.,  explored the effects of medial foot orthoses on patellofemoral stress during the stance phase of running using a musculoskeletal modelling approach [17]. Their findings showed that medial foot orthoses significantly reduced peak patellofemoral stress loading at this joint during running.

Although the effects of medial/lateral foot orthoses have been explored previously, they have habitually been examined during walking in pathological patients and thus their potential prophylactic effects on the kinetics and tibiocalcaneal kinematics of running have yet to be examined. Therefore, the aim of the current investigation was to examine the effects of foot orthotic devices with a 5° medial and lateral wedge on kinetics and tibiocalcaneal kinematics the during the stance phase of running. A clinical investigation of this nature may provide further insight into the potential efficacy of wedged foot orthoses for the prevention of chronic running injuries.

Methods

Participants

Twelve male runners (age 26.23 ± 5.76 years, height 1.79 ± 0.11 cm and body mass 73.22 ± 6.87 kg) volunteered to take part in this study. All runners were free from musculoskeletal pathology at the time of data collection and were not currently taking any medications. The participants provided written informed consent in accordance with the principles outlined in the Declaration of Helsinki. The procedure utilized for this investigation was approved by the University of Central Lancashire, Science, Technology, Engineering and Mathematics, ethical committee.

Orthoses

Commercially available orthotics (Slimflex Simple, High Density, Full Length, Algeos UK) were examined in the current investigation. The orthoses were made from Ethylene-vinyl acetate and had a shore A rating of 65. The orthoses were able to be modified to either a 5˚ varus or valgus configuration which spanned the full length of the device. The order that participants ran in each orthotic condition was counterbalanced.

Procedure

Participants completed five running trials at 4.0 m/s ± 5%. The participants struck an embedded piezoelectric force platform (Kistler Instruments, Model 9281CA) sampling at 1000 Hz with their right foot. Running velocity was monitored using infrared timing gates (SmartSpeed Ltd UK). The stance phase of the running cycle was delineated as the time over which > 20 N vertical force was applied to the force platform. Kinematic information was collected using an eight-camera optoelectric motion capture system with a capture frequency of 250 Hz. Synchronized kinematic and ground reaction force data were obtained using Qualisys track manager software (Qualisys Medical AB, Goteburg, Sweden).

The calibrated anatomical systems technique (CAST) was utilized to quantify tibiocalcaneal kinematics (18). To define the anatomical frames of the right foot, and shank, retroreflective markers were positioned onto the calcaneus, first and fifth metatarsal heads, medial and lateral malleoli, medial and lateral epicondyle of the femur. A carbon fiber tracking cluster was attached to the shank segment. The foot was tracked using the calcaneus, and first and fifth metatarsal markers. Static calibration trials were obtained with the participant in the anatomical position in order for the positions of the anatomical markers to be referenced in relation to the tracking clusters/markers.

Tibial accelerations were measured using an accelerometer (Biometrics ACL 300, Units 25-26 Nine Mile Point Ind. Est. Cwmfelinfach, Gwent United Kingdom) sampling at 1000 Hz. The device was attached to the tibia 0.08 m above the medial malleolus in alignment with its longitudinal axis (19). Strong adhesive tape was placed over the device and the lower leg to prevent artifact in the acceleration signal.

Processing

The running trials were digitized using Qualisys Track Manager (Qualysis, Sweden) and then exported as C3D files. Kinematic parameters were quantified using Visual 3-D software (C-Motion, USA) after the marker data was smoothed using a low-pass Butterworth 4th order zero-lag filter at a cutoff frequency of 12 Hz. Three-dimensional kinematic parameters were calculated using an XYZ cardan sequence of rotations where X represents the sagittal plane, Y represents the coronal plane and Z represents the transverse plane rotations (Sinclair et al., 2013). Trials were normalized to 100% of the stance phase then processed and averaged. In accordance with previous studies, the foot segment coordinate system was referenced to the tibial segment for ankle kinematics, whilst tibial internal rotation (TIR) was measured as a function of the tibial coordinate system in relation to the foot coordinate axes [21]. The 3-D kinematic tibiocalcaneal measures which were extracted for statistical analysis were: (1) angle at foot strike, (2) peak angle during stance and (3) relative range of motion (ROM) from footstrike to peak angle.

The tibial acceleration signal was filtered using a 60 Hz Butterworth zero lag 4th order low pass filter to prevent any resonance effects on the acceleration signal. Peak tibial acceleration (g) was defined as the highest positive axial acceleration peak measured during the stance phase. Average tibial acceleration slope (g/s) was quantified by dividing peak tibial acceleration by the time taken from footstrike to peak tibial acceleration and instantaneous tibial acceleration slope (g/s) was quantified as the maximum increase in acceleration between frequency intervals. From the force platform all parameters were normalized by dividing the net values by body weight. Instantaneous loading rate (BW/s) was calculated as the maximum increase in vertical force between adjacent data points.

Statistical analyses

Means, standard deviations and 95 % confidence intervals were calculated for each outcome measure for all orthotic conditions. Differences in kinetic and tibiocalcaneal kinematic parameters between orthoses were examined using one-way repeated measures ANOVAs, with significance accepted at the P≤0.05 level. Effect sizes were calculated using partial eta2 (pη2). Post-hoc pairwise comparisons were conducted on all significant main effects. The data was screened for normality using a Shapiro-Wilk which confirmed that the normality assumption was met. All statistical actions were conducted using SPSS v23.0 (SPSS Inc., Chicago, USA).

Results

Tables 1-3 and Figure 1 present differences in kinetics and tibiocalcaneal kinematics as a function of the different orthoses. The results indicate that the experimental orthoses significantly affected orthoses tibiocalcaneal kinematic parameters.

Medial Lateral No-orthotic
Mean SD 95% CI (Lower) 95% CI (Upper) Mean SD 95% CI (Lower) 95% CI (Upper) Mean SD 95% CI (Lower) 95% CI (Upper)
Coronal plane (+ = inversion & – = eversion)
 Angle at footstrike (°) -3.98 5.65 -7.57 -0.39 -3.77 5.64 -7.35 -0.19 -0.66 5.91 -4.41 3.09
 Peak eversion (°) -10.75 5.7 -14.38 -7.13 -14.11 6.48 -18.22 -9.99 -12.37 5.43 -15.82 -8.92
 Relative ROM (°) 6.77 2.78 5.00 8.54 10.34 3.44 8.15 12.53 11.71 3.26 9.64 13.78
Transverse plane (+ = external & – = internal)
 Angle at footstrike (°) -11.78 2.72 -13.51 -10.05 -15.01 2.81 -16.80 -13.22 -14.41 2.97 -16.29 -12.52
 Peak rotation (°) -6.80 3.10 -8.78 -4.83 -5.6 3.94 -8.10 -3.09 -5.05 3.33 -7.17 -2.93
 Relative ROM (°) 4.97 0.86 4.43 5.52 9.41 1.33 8.56 10.26 9.35 1.44 8.44 10.27

Table 1 Ankle kinematics (mean, SD & 95% CI) in the coronal and transverse planes as a function of the different orthotic conditions.

Medial Lateral No-orthotic
Mean SD 95% CI (Lower) 95% CI (Upper) Mean SD 95% CI (Lower) 95% CI (Upper) Mean SD 95% CI (Lower) 95% CI (Upper)
Transverse plane (+ =  internal & – =external)
 Angle at footstrike (°) 8.57 3.16 6.56 10.57 9.74 4.01 7.20 12.29 6.51 3.98 3.98 9.04
 Peak TIR (°) 13.54 4.28 10.82 16.27 15.89 5.65 12.30 19.48 13.98 4.58 11.07 16.89
 Relative ROM (°) 4.98 2.68 3.28 6.68 6.14 3.54 3.89 8.39 7.47 3.75 5.09 9.85

Table 2 Tibial internal rotation parameters (mean, SD & 95% CI) as a function of the different orthotic conditions.

Medial Lateral No-orthotic
Mean SD 95% CI (Lower) 95% CI (Upper) Mean SD 95% CI (Lower) 95% CI (Upper) Mean SD 95% CI (Lower) 95% CI (Upper)
Peak tibial acceleration (g) 9.83 4.50 6.98 12.69 9.97 4.88 6.87 13.07 9.41 4.76 6.38 12.44
Average tibial acceleration slope (g/s) 362.73 196.31 238.01 487.46 367.37 219.63 227.83 506.91 369.52 257.85 205.69 533.35
Instantaneous tibial acceleration slope (g/s) 866.20 459.40 574.31 1158.09 867.71 554.16 515.61 1219.81 776.85 529.86 440.20 1113.51
Instantaneous load rate (BW/s) 156.17 58.72 118.86 193.48 161.77 71.57 116.30 207.25 134.49 44.62 106.14 162.84

Table 3 Kinetic and tibial acceleration parameters (mean, SD & 95% CI) as a function of the different orthotic conditions.

Figure 1 Tibiocalcaneal kinematics as a function of the different orthotic conditions; a= ankle coronal plane angle, b= ankle transverse plane angle & c = tibial internal rotation, (black = lateral, dash = medial & grey = no-orthotic), (IN = inversion, EXT = external & INT = internal).

Kinetics and tibial accelerations

No significant (P>0.05) differences in kinetics/tibial acceleration parameters were observed between orthotic conditions.

Tibiocalcaneal kinematics

In the coronal plane a significant main effect (F (2, 22) = 25.58, P<0.05, pη2 = 0.70) was found for the magnitude of peak eversion. Post-hoc pairwise comparisons showed that peak eversion was significantly larger in the lateral in relation to the medial (P=0.0000007) and no-orthotic (P=0.01) conditions. In addition, it was also revealed that peak eversion was significantly greater in the no-orthotic (P=0.008) in comparison to the medial orthotic condition. In addition, a significant main effect (F (2, 22) = 25.58, P<0.05, pη2 = 0.74) was noted for relative eversion ROM. Post-hoc pairwise comparisons showed that relative eversion ROM was significantly larger in the lateral (P=0.0000006) and no-orthotic (P=0.00001) in relation to the medial condition.

In the transverse plane a significant main effect (F (2, 22) = 116.11, P<0.05, pη2 = 0.91) was noted for relative transverse plane ankle ROM. Post-hoc pairwise comparisons showed that relative transverse plane ankle ROM was significantly larger in the lateral (P=0.0000001) and no-orthotic (P=0.0000008) in relation to the medial condition.

In addition, a significant main effect (F (2, 22) = 5.99, P<0.05, pη2 = 0.36) was found for the magnitude of peak TIR. Post-hoc pairwise comparisons showed that peak TIR was significantly larger in the lateral in relation to the medial (P=0.007) and no-orthotic (P=0.025) conditions. Finally, a significant main effect (F (2, 22) = 7.55, P<0.05, pη2 = 0.41) was noted for relative TIR ROM. Post-hoc pairwise comparisons showed that relative TIR ROM was significantly larger in the lateral (P=0.04) and no-orthotic (P=0.007) in relation to the medial condition.

Discussion

The aim of the current investigation was to examine the effects of foot orthotic devices with a 5° medial and lateral wedge on kinetics and tibiocalcaneal kinematics the during the stance phase of running. This is, to the authors’ knowledge, the first investigation to concurrently examine the influence of different orthotic wedge configurations on the biomechanics of running. An investigation of this nature may, therefore, provide further insight into the potential prophylactic efficacy of wedged foot orthoses for the prevention of chronic running injuries.

The current study importantly confirmed that no significant differences in impact loading or axial tibial accelerations were evident as a function of the experimental orthotic conditions. This observation opposes those of Sinclair et al., Laughton et al. and Dixon, who demonstrated that foot orthoses significantly reduced the magnitude of axial impact loading during the stance phase of running [5,7,8]. However, the findings are in agreement with those noted by Butler et al,  who similarly observed that the magnitude of axial impact loading did not differ significantly whilst wearing rigid orthoses [6]. Although not all of the aforementioned investigations have published hardness ratings, at a shore A grade of 65 it is likely that the orthoses examined in the current explanation were more rigid than those utilized by Sinclair et al., Laughton et al. and Dixon [5,7,8]. It is proposed that the divergence between investigations relates to differences in hardness characteristics of the experimental orthoses. The magnitude of impact loading is governed by the rate of change in momentum of the decelerating limb as the foot strikes the ground [22]; as such, it appears that the orthoses examined in this analysis were not sufficiently compliant to provide any reduction in impact loading.

Of further importance to the current investigation is that the medial orthoses significantly reduced eversion and TIR parameters in relation to the lateral and no-orthotic conditions. It is likely that this observation relates to the mechanical properties of the medial wedge which is designed specifically to rotate the foot segment into a more inverted position. This finding has potential clinical significance as excessive rearfoot eversion and associated TIR parameters are implicated in the etiology of a number of overuse injuries such as tibial stress syndrome, plantar fasciitis, patellofemoral syndrome and iliotibial band syndrome [23-25]. This observation therefore suggests that medial orthoses may be important for the prophylactic attenuation of chronic running related to excessive eversion/ TIR.

The findings from the current study importantly show that whilst lateral orthoses are effective in attenuating pain symptoms [9] and reducing the magnitude of the external knee adduction moment [13-15] in patients with medial compartment tibiofemoral osteoarthritis, they may concurrently place runners at risk from chronic pathologies distinct from the medial aspect of the tibiofemoral joint. It appears based on the findings from the current investigation that caution should be exercised when prescribing lateral wedge orthoses without a thorough assessment of the runners’ individual characteristics.  

A limitation, in relation to the current investigation, is that only the acute effects of the wedged insoles were examined. Therefore, although the medial orthoses appear to prophylactically attenuate tibiocalcaneal risk factors linked to the etiology of injuries, it is currently unknown whether this will prevent or delay the initiation of injury symptoms. Furthermore, the duration over which the orthoses would need to be utilized in order to mediate a clinically meaningful change in patients is also not currently known. A longitudinal examination of medial/lateral orthoses in runners would therefore be of practical and clinical relevance in the future. A further potential limitation is that only male runners were examined as part of the current investigation. Females are known to exhibit distinct tibiocalcaneal kinematics when compared to male recreational runners, with females being associated with significantly greater eversion and TIR parameters compared to males [26]. Furthermore, females are renowned for being at increased risk from tibiofemoral joint degeneration in comparison to males [27], and experimental findings have shown that degeneration may also be more prominent at different anatomical aspects of the knee in females in relation to males [28]. This suggests that the requirements of females, in terms of wedged orthotic intervention, may differ from those of male runners, thus it would be prudent for future biomechanical investigations to repeat the current study using a female sample.

In conclusion, despite the fact that the biomechanical effects of wedged foot orthoses have been examined previously, current knowledge with regards to the effects of medial and lateral orthoses on the kinetics and tibiocalcaneal kinematics of running have yet to be explored. This study adds to the current literature in the field of biomechanics by giving a comprehensive comparative examination of kinetic and tibiocalcaneal kinematic parameters during the stance phase of running whilst wearing medial and lateral orthoses. The current investigation importantly showed that medial orthoses significantly attenuated eversion and TIR parameters in relation to the lateral and no-orthotic conditions. The findings from this study indicate therefore that medial orthoses may be effective in attenuating tibiocalcaneal kinematic risk factors linked to the etiology of chronic pathologies in runners.

References

  1. Lee, D.C., Pate, R.R., Lavie, C.J., Sui, X., Church, T.S., Blair S.N. (2014). Leisure-time running reduces all-cause and cardiovascular mortality risk. Journal of the American College of Cardiology. 64, 472-481.
  2. van Gent, B.R., Siem, D.D., van Middelkoop, M., van Os, T.A., Bierma-Zeinstra, S.S., Koes, B.B. (2007). Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review. British Journal of Sports Medicine. 41, 469-480.
  3. McMillan, A., Payne, C. (2008). Effect of foot orthoses on lower extremity kinetics during running: a systematic literature review. Journal of Foot and Ankle Research. 13, 1-13.
  4. Mills, K., Blanch, P., Chapman, A. R., McPoil, T. G., Vicenzino, B. (2010). Foot orthoses and gait: a systematic review and meta-analysis of literature pertaining to potential mechanisms. British Journal of Sports Medicine, 44, 1035-1046.
  5. Sinclair, J., Isherwood, J., Taylor, P.J. (2014). Effects of foot orthoses on kinetics and tibiocalcaneal kinematics in recreational runners. Foot and Ankle Online Journal, 7, 3-11.
  6. Butler, R. J., Davis, I. M., Laughton, C. M., Hughes, M. (2003). Dual-function foot orthosis: effect on shock and control of rearfoot motion. Foot & ankle international, 24, 410-414.
  7. Laughton, C. A., Davis, I. M., Hamill, J. (2003). Effect of strike pattern and orthotic intervention on tibial shock during running. Journal of Applied Biomechanics, 19, 153-168.
  8. Dixon, S.J. (2007). Influence of a commercially available orthotic device on rearfoot eversion and vertical ground reaction force when running in military footwear. Military medicine, 172, 446-450.
  9. Parkes, M. J., Maricar, N., Lunt, M., LaValley, M. P., Jones, R. K., Segal, N. A., Felson, D. T. (2013). Lateral wedge insoles as a conservative treatment for pain in patients with medial knee osteoarthritis: a meta-analysis. JAMA, 310, 722-730.
  10. Reilly, K. A., Barker, K. L., Shamley, D. (2006). A systematic review of lateral wedge orthotics-how useful are they in the management of medial compartment osteoarthritis?. The Knee, 13, 177-183.
  11. Rafiaee, M., Karimi, M. T. (2012). The effects of various kinds of lateral wedge insoles on performance of individuals with knee joint osteoarthritis. International Journal of Preventive Medicine, 3, 693-698.
  12. Birmingham, T.B., Hunt, M.A., Jones, I.C., Jenkyn, T.R., Giffin, J.R. (2007). Test–retest reliability of the peak knee adduction moment during walking in patients with medial compartment knee osteoarthritis. Arthritis Care & Research. 57, 1012-1017.
  13. Kakihana, W., Torii, S., Akai, M., Nakazawa, K., Fukano, M., Naito, K. (2005). Effect of a lateral wedge on joint moments during gait in subjects with recurrent ankle sprain. American Journal of Physical Medicine & Rehabilitation, 84, 858-864.
  14. Butler, R. J., Marchesi, S., Royer, T., Davis, I. S. (2007). The effect of a subject‐specific amount of lateral wedge on knee mechanics in patients with medial knee osteoarthritis. Journal of Orthopaedic Research, 25, 1121-1127.
  15. Kakihana, W., Akai, M., Yamasaki, N., Takashima, T., Nakazawa, K. (2004). Changes of joint moments in the gait of normal subjects wearing laterally wedged insoles. American Journal of Physical Medicine & Rehabilitation, 83, 273-278.
  16. Boldt, A.R., Willson, J.D., Barrios, J.A., Kernozek, T.W. (2013). Effects of medially wedged foot orthoses on knee and hip joint running mechanics in females with and without patellofemoral pain syndrome. Journal of Applied Biomechanics. 29, 68-77.
  17. Sinclair, J., Vincent, H., Selfe, J., Atkins, S., Taylor, P.J., Richards, J. (2015). Effects of foot orthoses on patellofemoral load in recreational runners. Foot and Ankle Online Journal, 8, 5-12.
  18. Cappozzo, A., Catani, F., Leardini, A., Benedeti, M.G., Della, C.U. (1995). Position and orientation in space of bones during movement: Anatomical frame definition and determination. Clinical Biomechanics, 10, 171-178.
  19. Sinclair, J., Bottoms, L., Taylor, K., Greenhalgh, A. (2010). Tibial shock measured during the fencing lunge: the influence of footwear. Sports Biomechanics, 9, 65-71.
  20. Sinclair, J., Taylor, P.J., Edmundson, C.J., Brooks, D., Hobbs, S.J. (2013). Influence of the helical and six available Cardan sequences on 3D ankle joint kinematic parameters. Sports Biomechanics, 11, 430-437.
  21. Eslami, M., Begon, M., Farahpour, N., Allard, P. (200). Forefoot–rearfoot coupling patterns and tibial internal rotation during stance phase of barefoot versus shod running. Clinical Biomechanics, 22, 74-80.
  22. Whittle, M.W. (1999). Generation and attenuation of transient impulsive forces beneath the foot: a review. Gait & posture, 10, 264-267.
  23. Viitasalo, J.T., Kvist, M. (1983). Some biomechanical aspects of the foot and ankle in athletes with and without shin splints. The American Journal of Sports Medicine, 11, 125-130.
  24. Lee, S.Y., Hertel, J., Lee, S.C. (2010). Rearfoot eversion has indirect effects on plantar fascia tension by changing the amount of arch collapse. The Foot, 20, 64-70.
  25. Barton, C. J., Levinger, P., Menz, H. B., Webster, K. E. (2009). Kinematic gait characteristics associated with patellofemoral pain syndrome: a systematic review. Gait & posture, 30, 405-416.
  26. Sinclair, J., Taylor, P. J. (2014). Sex differences in tibiocalcaneal kinematics. Human Movement, 15, 105-109.
  27. Hame, S.L., Alexander, R.A. (2013). Knee osteoarthritis in women. Current Reviews in Musculoskeletal Medicine. 6, 182-187.
  28. Hanna, F.S., Teichtahl, A.J., Wluka, A.E., Wang, Y., Urquhart, D.M., English, D.R., Cicuttini, F.M. (2009). Women have increased rates of cartilage loss and progression of cartilage defects at the knee than men: a gender study of adults without clinical knee osteoarthritis. Menopause. 16, 666-670.

Charcot foot management using MASS posture foot orthotics: A case study

by Edward S. Glaser DPM1; David Fleming BS2*; Barbara Glaser2

The Foot and Ankle Online Journal 10 (3): 4

Background: A 62-year old male being treated for Charcot arthropathy of his right foot at the VA Medical Center in Orlando, FL.  The patient was using a knee walker with a below knee cast at onset of treatment.
Methods:  Custom rocker sole walking boot with built in EVA MASS posture orthotic and MASS orthotic Therapy
Results:  Quality of life improvements.  As the Charcot foot remodeled it coalesced into a foot with an increased medial longitudinal arch allowing for return closer to normal gait and footwear.  No ulcerogenesis was noted with aggressive orthotic therapy.  Protective sensation partially returned to feet bilaterally.
Conclusions:  An increase in patient quality of life without introducing ulcers.   More research needs to be done to determine if this treatment protocol contributes to protective sensation returning to patients with DPN.

Keywords: Charcot foot, diabetic neuropathy, orthoses, MASS Posture

ISSN 1941-6806
doi: 10.3827/faoj.2017.1003.0004

1 – Founder and CEO of Sole Supports, Inc.
2 – Sole Supports, Inc.
* – Corresponding author: dfleming@solesupports.com


The patient is a 62-year old, well nourished, caucasian male with a 12-year history of Type II Diabetes Mellitus. He has experienced neuropathy for 9 years and for the last 7 years he has been profoundly numb bilaterally distal to the ankle. Following a 10-month period of misdiagnosis, he was diagnosed with Charcot foot on November 18, 2015, at the Orlando VAMC. Podiatric treatment for four months prior consisted of ambulating in a BK cast with a knee walker. Casts were reapplied every 3-4 weeks. During the four months of immobilization, the patient noted considerable atrophy of the right gastroc-soleus muscle and loss of his medial longitudinal arch. The patient’s right foot had become a semi-rigid rocker sole foot (Figure 1).

Figure 1 Rocker sole foot.

When the patient was first seen, insensitivity was confirmed with a Semmes Weinstein 5.07 monofilament test bilaterally. No ulcers were visibly present. The patient’s right foot had significant swelling and the patient had gone from a size 12.5 USA (M) shoe to a size 14 USA (M) shoe prior to casting according to the patient.

To prevent amputation of his foot, a prospective protocol was created as the patient progressed.  If at any time the patient developed an ulcer, the project would have been terminated and traditional care would have resumed.

Methods

A Semmes Weinstein 5.07 monofilament was used to determine the patient’s protective sensation.  The locations for monofilament testing were as follows: the plantar aspect of metatarsal heads and distal phalanges 1,3,5. The plantar aspect of the heel, medial arch, and lateral arch. The dorsal aspect of the skin at the base of metatarsal 3, and plantar aspect of the heel, bilaterally [1].

Figure 2 Paper Test shown with MASS Orthotic.

The Paper Test (Figure 2) consisted of the patient weight bearing on the affected foot with a piece of paper placed under both the forefoot and the rearfoot.  The practitioner then attempted to remove the piece of paper by pulling it anteriorly/posteriorly.  If the paper tore then that was a positive result, if the paper slid out it was a negative result.  A positive result meant that part of the foot was providing adequate force to the ground, resulting in the paper being torn.  A negative result meant that part of the foot was not providing adequate force to the ground and slid out un torn.  The paper test was used to determine when it was appropriate to move him from the custom MASS posture rocker sole shoe boot to the MASS orthotic  inside of a diabetic shoe.

Figure 3  Custom walking boot with EVA Shell MASS Posture Orthotic.

Following removal of the  plaster cast, a custom rocker-sole post-op boot with an EVA shell MASS posture orthotic built in (Figure 3) on 1/28/16.  That boot caused irritation and so the design was refined and a new rocker-sole boot with an EVA shell MASS Posture orthotic fitted in the boot (Figure 4) was created and dispensed to patient on 3/4/2016.  The boot (Figure 4) was removed and replaced with a modified golf shoe boot with an EVA shell MASS Posture orthotic fitted into the boot (Figure 5), which was dispensed to the patient on 3/25/2015.  Each change of successive custom boot was modeled from a new, more aggressively captured medial longitudinal arch.  The golf shoe boot (Figure 5) was removed and replaced with an ultrahigh molecular weight polyethylene shell. MASS orthotic (O1) for use with his diabetic shoes.  O1 was dispensed and fitted on 5/6/2016 with use of a full foot lift for his left foot to compensate for the edema on his right foot.   After the edema decreased another MASS orthotic with a polyethylene shell (O2) was dispensed and fitted, for his normal tennis shoes, on 8/25/2016, along with reducing the full foot lift on his left foot.

Figure 4 Refined Custom walking boot with EVA Shell MASS Posture Orthotic.

Figure 5 Modified golf shoe boot with EVA Shell MASS Posture Orthotic.

Results

Our patient initially presented completely insensate with diabetic neuropathy on 1/28/2016.  On 3/25/2016 the patient had regained 6/10 sensation on the right foot and 8/10 on left with the monofilament test.  On 5/6/2016 the patient had a 8/10 sensation on right foot and 10/10 on left.  It should be noted that the patient has been fully compliant keeping his diabetes in control.

Although the patient’s Charcot foot has now fully fused, the foot appears to have remodeled and partially regained the medial longitudinal arch (Figure 6).  The authors believe that this is due, at least in part, to the patient weight bearing in a MASS Posture.  No ulcers developed with the forces applied to the foot.  This is due, at least in part, to the even distribution of body weight across the plantar surface of the foot.  

Figure 6 Clinical view of foot after treatment.

The patient is leading a normal life that includes golf and walking approximating an ideal gait cycle on both hard flat surfaces (hardwood) and uneven flexible surfaces (grass).  

Discussion

For peripheral neuropathy, it is common conventional wisdom that only the levels of Hgb A1C correlate to the presence of neuropathy.  This particular case, along with previous findings of Michael Graham, suggest that there is a secondary biomechanical etiology that may contribute to Diabetic Peripheral Neuropathy (DPN).  Michael Graham showed that reversing neuropathy could be obtained by reducing tension on the neurovascular bundle and the intracompartmental pressures of the posterior tibial nerve utilizing an extra osseous talotarsal implant [2].  This helps explain why some diabetics with equally poor Hgb A1C’s develop DPN but others do not. The biomechanical factor is postulated to involve the mechanical elongation of the perineurium surrounding the posterior tibial nerve.  As the foot drops in posture, the neurovascular bundle is pulled plantarly increasing tension due to elongation [3].  This may cause the perineurium to compress the nerve while increasing fluid pressure within the sheath, contributing to its loss of function.

Conclusion

The authors postulate that using MASS Posture orthotics in combination with controlling diabetes may prevent or, in some cases reverse, diabetic neuropathy by reposturing the foot and thereby decreasing nerve tension and entrapment while evenly distributing the force from the body across the entire plantar surface of the foot.  Additionally, the authors postulate that it is possible during active Charcot to remodel the medial longitudinal arch closer to an idealized foot posture.  Further research is required with an established protocol prior to treatment with a larger sample size to provide more data to verify results.

References

  1. Smieja, M., Hunt, D. L., Edelman, D., Etchells, E., Cornuz, J., Simel, D. L. and For The International Cooperative Group for Clinical Examination Research (1999), Clinical Examination for the Detection of Protective Sensation in the Feet of Diabetic Patients. Journal of General Internal Medicine, 14: 418–424. 
  2. Graham ME, Jawrani NT, Goel VK. The Effect of HyProCure® Sinus Tarsi Stent on Tarsal Tunnel Compartment Pressures in Hyperpronating Feet. The Journal of Foot and Ankle Surgery. 2011;50(1):44-49. 
  3. Graham ME, Jawrani NT, Goel VK. Evaluating Plantar Fascia Strain in Hyperpronating Cadaveric Feet Following an Extra-osseous Talotarsal Stabilization Procedure. The Journal of Foot and Ankle Surgery. 2011;50(6):682-686. 

Effects of foot orthoses on patellofemoral load in recreational runners

by Sinclair J1, Vincent H1, Selfe J2, Atkins S1, Taylor PJ3, and Richards J2pdflrg

The Foot and Ankle Online Journal 8 (2): 5

The most common chronic injury in recreational runners is patellofemoral pain. Whilst there is evidence to suggest that orthotic intervention may reduce symptoms in runners who experience patellofemoral pain the mechanism by which their clinical effects are mediated is currently poorly understood. The aim of the current investigation was to determine whether foot orthoses reduce the loads experienced by the patellofemoral joint during running. Patellofemoral loads were obtained from fifteen male runners who ran at 4.0 m·s-1. Patellofemoral loads with and without orthotics were contrasted using paired t-tests. The results showed that patellofemoral joint loads were significantly reduced as a function of running with the orthotic device. The current investigation indicates that through reductions in patellofemoral loads, foot orthoses may serve to reduce the incidence of chronic running injuries at this joint.

Keywords: patellofemoral pain, orthoses, biomechanics

ISSN 1941-6806
doi: 10.3827/faoj.2015.0802.0005

Address correspondence to: Dr. Paul John Taylor
School of Psychology, University of Central Lancashire, Preston, Lancashire, PR1 2HE.
PJTaylor@uclan.ac.uk

1. Division of Sport Exercise and Nutritional Sciences, School of Sport Tourism and Outdoors, University of Central Lancashire.
2. Allied Health Research Unit, School of Sport Tourism and Outdoors, University of Central Lancashire.
3. School of Psychology, University of Central Lancashire.


D
istance running has been shown to be physiologically beneficial [1]. However despite this, research examining the incidence of running injuries indicates that chronic pathologies are a prominent complaint for both recreational and competitive runners [2], with an incidence rate of around 70% during the course of a year [3].

The most common chronic injury in recreational runners is patellofemoral pain, which is characterized by pain linked to the contact of the posterior surface of the patella with the femur during dynamic activities [4].

Pain symptoms, which develop as a function of patellofemoral disorders can be debilitating and patellofemoral pain may also be a pre-cursor to the progression of osteoarthritis in later life [5,6]. Conservative treatment of patellofemoral disorders is preferable to operative interventions, and the efficacy of a number of conservative approaches has been explored in the literature.

There is evidence to suggest that orthotic intervention may reduce symptoms in runners who experience patellofemoral pain. Collins et al. prospectively examined the efficacy of foot orthoses in the management of patellofemoral pain [7]. Foot orthoses were shown to produce clinically meaningful improvements in pain symptoms. Eng et al. examined the effectiveness of soft foot orthotics in the treatment of patients with patellofemoral pain syndrome [8]. Participants were assigned to either an orthotic or control condition and subjects reported their perceived pain levels over an 8-week period using a visual analogue scale. It was shown that the soft foot orthotics may be an effective treatment mechanism for patellofemoral pain. Batron et al. investigated the effects of 12-week intervention using of non-custom foot orthoses on self-reported improvements in pain symptoms [9]. It was shown that 25% of participants showed marked improvements in patellofemoral pain symptoms as a function of orthotic intervention. Pitman & Jack monitored the efficacy of foot orthoses as a treatment modality for patellofemoral pain [10]. They found that orthotics produced reductions in pain symptoms, which led to the conclusion that orthotics may be an effective treatment mechanism.

Despite the potential efficacy of foot orthoses in the prevention/treatment of patellofemoral pain symptoms, there is a paucity of research investigating any potential alterations in loading at this joint that may be mediated through orthotic intervention. The aim of the current investigation was therefore to determine whether foot orthoses reduce the loads experienced by the patellofemoral joint during the stance phase of running. This study tests the hypothesis that orthoses will reduce patellofemoral load during running.

Methods

Participants

Fifteen male participants (Age 25.76 ± 5.21 years; height 1.74 ± 0.06 m; mass 71.15 ± 4.84 kg) took part in the current study. Participants were all recreational runners who engaged in training at least three times per week. Ethical approval for this project was obtained from the University and each participant provided informed consent in written form in accordance with the declaration of Helsinki.

Orthotic device

Commercially available orthotics (Sorbothane, shock stopper sorbo Pro; Nottinghamshire UK) were examined in the current investigation. Although the right side was selected for analysis orthotic devices were placed inside both shoes.

Procedure

Participants completed five trials running at 4.0 m·s-1 with and without orthotics. The order in which participants ran in each condition was counterbalanced. Participants ran over an embedded piezoelectric force platform (Kistler Instruments, Model 9281CA) operating at 1000 Hz [11]. Running velocity was controlled using infrared timing gates (SmartSpeed Ltd UK). A deviation of ±5% from the pre-determined velocity was allowed. Participants struck the force platform with their right (dominant) limb and five trials were obtained from each footwear condition. Three-dimensional (3-D) kinematics and ground reaction forces data were collected synchronously. The stance phase was defined as the duration over which >20 N of vertical force was applied to the force platform [12]. Kinematic information was obtained using an eight camera optoelectric motion capture system (Qualisys Medical AB, Goteburg, Sweden) using a capture frequency of 250 Hz. Dynamic calibration of the motion capture system was conducted prior to data collection.

The current investigation used the calibrated anatomical systems technique (CAST) to model the lower extremity segments in six degrees of freedom [13]. To define the anatomical frame of the right shank and thigh, retroreflective markers were positioned unilaterally to the medial and lateral malleoli, medial and lateral epicondyle of the femur and greater trochanter. Rigid technical tracking clusters were positioned on the shank and thigh segments. Static trials were conducted in order for the positions of the anatomical markers to be referenced in relation to the tracking markers/clusters, following which those not required for tracking were removed.

Data processing

Ground reaction force and kinematic data were smoothed using cut-off frequencies of 50 Hz and 12 Hz with a low-pass Butterworth 4th order filter using Visual 3-D (C-Motion, Germantown, MD, USA). Newton-Euler inverse-dynamics were used which allowed knee joint moments to be calculated. Knee loading was examined through extraction of peak knee extensor moment, peak knee abduction moment, patellofemoral contact force (PTCF) and patellofemoral contact pressure (PTCP).

A previously utilized algorithm was used to quantify PTCF and PTCP [14]. This method has been utilized previously to resolve differences in PTCF and PTCP when using different footwear [15,16,17] and between those with and without patellofemoral pain [18]. PTCF (B.W) was estimated using knee flexion angle (KFA) and knee extensor moment (KEM) through the biomechanical model of Ho et al [19]. The moment arm of the quadriceps (QMA) was calculated as a function of KFA using a non-linear equation, based on cadaveric information presented by van Eijden et al. [20]:

QMA = 0.00008 KFA 3 – 0.013 KFA 2 + 0.28 KFA + 0.046

Quadriceps force (FQ) was calculated using the below formula:

FQ = KEM / QMA

PTCF was estimated using the FQ and a constant (C):

PTCF = FQ C

The C was described in relation to KFA using the equation described by van Eijden et al. [20]:

C = (0.462 + 0.00147 KFA 2 – 0.0000384 KFA 2) / (1 – 0.0162 KFA + 0.000155 KFA 2 – 0.000000698 KFA 3)

PTCP (MPa) was calculated using the PTCF divided by the patellofemoral contact area. The contact area was delineated by fitting a 2nd-order polynomial curve to the data of Powers et al., [21] showing patellofemoral contact areas at varying levels of KFA.

PTCP = PTCF / contact area

PTCF loading rate (B.W/s) was also calculated as a function of the change in PTFC from initial contact to peak force divided by the time to peak force.

Statistical Analyses

The data were tested for normality using a Shapiro-Wilk test which confirmed that the data were suitable for parametric testing. Means and standard deviations were calculated for each running condition. Differences in the outcome 3D kinematic parameters were examined using paired samples t-tests. The alpha level required for statistical significance was adjusted to p≤0.008 based on the number of comparisons being made. Effect sizes for all significant observations were calculated using a Cohen’s D statistic. All statistical analyses were conducted using SPSS v21.0 (SPSS Inc, Chicago, USA).

Results

 fig1

Figure 1 Knee kinetics and kinematics as a function of orthotic intervention, black = no-orthotic and dash = orthotic, (a= knee angle, b = sagittal knee moment c = PTCF, d = PTCP, e = coronal knee moment) (FL = flexion, EX = extension, AD = adduction).

Peak knee extensor moment was significantly (t (14) = 4.11, p<0.008, D = 2.20) greater in the non-orthotic condition compared to running with orthotics (Table 1, Figure 1a). In addition PTFC (t (14) = 3.96, p<0.008, D = 2.12) and PTCP (t (14) = 4.57, p<0.008, D = 2.44) were also shown to be significantly greater in the non-orthotic condition compared to running with orthotics (Table 1, Figure 1bc). Finally PTCF loading rate was shown to be significantly (t (14) = 3.88, p<0.008, D = 2.07) higher when running without orthotics (Table 1).

table1

Table 1 Knee loads as a function of orthotic intervention. Notes: * = significant difference p<0.008.

Discussion

This study aimed to determine whether foot orthoses reduce the loads experienced by the patellofemoral joint during the stance phase of running. Previous analyses have examined the efficacy of orthotic devices in the treatment of patellofemoral disorders, but this represents the first investigation to examine the effects of orthotic devices on the loads experienced by the joint itself.

In support of our hypothesis, the key observation from the current investigation is that patellofemoral load parameters were significantly reduced with the presence of orthotic intervention when compared to running without orthotic inserts. This finding may have relevance clinically and serve to provide further insight into the mechanisms by which foot orthoses serve to attenuate the symptoms of patellofemoral pain Ho et al. [19]. The aetiology and pathogenesis of patellofemoral disorders are a function of habitual and excessive loads experienced by the patellofemoral joint itself, which could account for the high incidence of patellofemoral disorders in runners. This current investigation shows that using foot orthoses may be a potential mechanism by which runners are able to attenuate their risk of injury through reductions in knee joint loading.

It is hypothesized that the reductions in patellofemoral kinetics observed in the current study are linked to the additional midsole cushioning associated with the orthotic device. When running with increased midsole cushioning runners typically utilize reduced knee flexion angle at footstrike and throughout the stance phase (Figure 1a). Reductions in knee flexion are associated with lengthening of the quadriceps moment arm, which serves to reduce the load experienced by the patellofemoral joint as PTFC and PTCP are governed by the force generated in the quadriceps [19].

In conclusion, the findings from the current study show that running with foot orthotics are associated with significant reductions in patellofemoral loading parameters when compared to running without orthotic intervention. Given the proposed relationship between the magnitude of patellofemoral loading and the aetiology of patellofemoral pathology, it is proposed that the risk of the developing running related injuries at the patellofemoral joint may be attenuated as a function of orthotic intervention.

Acknowledgements

The authors wish to thank Robert Graydon for his technical assistance during data collection.

References

  1. Denvir MA, Gray GA. Run for your life: exercise, oxidative stress and the ageing endothelium. Journal of Physiology 2009 Sep;587(Pt17):4137-4138. PubMed
  2. Hreljac A. Impact and overuse injuries in runners. Medicine & Science in Sports & Exercise 2004 May;36(5):845-849. PubMed
  3. Marti B, Vader JP, Minder CE, Abelin T. On the epidemiology of running injuries The 1984 Bern Grand-Prix study. American Journal of Sports Medicine 1988 May-Jun;16(3): 285-294. PubMed
  4. Besier TF, Gold GE, Beaupre GS, Delp SL. A modeling framework to estimate patellofemoral joint cartilage stress in vivo. Medicine & Science in Sports & Exercise 2005 Nov;37(11):1924–1931. PubMed
  5. Crossley KM. Is patellofemoral osteoarthritis a common sequela of patellofemoral pain?. British Journal of Sports Medicine 2014 Mar;48(6):409-410. PubMed
  6. Thomas MJ, Wood L, Selfe J, Peat G. Anterior knee pain in younger adults as a precursor to subsequent patellofemoral osteoarthritis: a systematic review. BMC Musculoskeletal Disorders 2010 Sep;11: 201. PubMed
  7. Collins N, Crossley K, Beller E, Darnell R, McPoil T, Vicenzino B. Foot orthoses and physiotherapy in the treatment of patellofemoral pain syndrome: randomised clinical trial. British Medical Journal 2008 Oct; 337:1735. link
  8. Eng JJ, Pierrynowski MR. Evaluation of soft foot orthotics in the treatment of patellofemoral pain syndrome. Physical Therapy 1993 Feb;73(2):62-68. PubMed
  9. Barton CJ, Menz HB, Crossley KM. Clinical predictors of foot orthoses efficacy in individuals with patellofemoral pain. Medicine & Science in Sports & Exercise 2011 Sep;43(9):1603-1610. PubMed
  10. Pitman D, Jack D. A clinical investigation to determine the effectiveness of biomechanical foot orthoses as initial treatment for patellofemoral pain syndrome. Journal of Prosthetics & Orthotics 2000;12(4):110–116. link
  11. Sinclair J, Hobbs SJ, Taylor PJ, Currigan G, Greenhalgh A. The influence of different force measuring transducers on lower extremity kinematics. Journal of Applied Biomechanics 2014 Jul; 40(3):476-479. PubMed
  12. Sinclair J, Edmundson CJ, Brooks D, Hobbs SJ. Evaluation of kinematic methods of identifying gait Events during running. International Journal of Sport Science & Engineering 2011 Aug; 5(3): 188-192. link
  13. Cappozzo A, Catani F, Leardini A, Benedeti MG, Della CU. Position and orientation in space of bones during movement: Anatomical frame definition and determination. Clinical Biomechanics 1995 Jun;10(4):171-178. PubMed
  14. Ward SR, Powers CM. The influence of patella alta on patellofemoral joint stress during normal and fast walking. Clinical Biomechanics 2004 Dec;19(10):1040–1047. PubMed
  15. Bonacci J, Vicenzino B, Spratford W, Collins P. Take your shoes off to reduce patellofemoral joint stress during running. British Journal of Sports Medicine 2014 Mar;48(6):425-428. PubMed
  16. Kulmala JP, Avela J, Pasanen K, Parkkari J. Forefoot strikers exhibit lower running-induced knee loading than rearfoot strikers. Medicine & Science in Sports & Exercise 2013 Dec;45(12):2306-2313. PubMed
  17. Sinclair J. Effects of barefoot and barefoot inspired footwear on knee and ankle loading during running. Clinical Biomechanics 2014 Apr;29(4):395-399. PubMed
  18. Keino BJ, Powers CM. Patellofemoral stress during walking in persons with and without patellofemoral pain. Medicine & Science in Sports & Exercise 2002 Oct;34(10):1582–1593. PubMed
  19. Ho KY, Blanchette MG, Powers CM. The influence of heel height on patellofemoral joint kinetics during walking. Gait & Posture 2012 Jun;36(2):271-275. PubMed
  20. van Eijden TM, Kouwenhoven E, Verburg J, Weijs WA. A mathematical model of the patellofemoral joint. Journal of Biomechanics 1986;19(3):219–229. PubMed
  21. Powers CM, Lilley JC, Lee TQ. The effects of axial and multiplane loading of the extensor mechanism on the patellofemoral joint. Clinical Biomechanics 1998 Dec;13(8):616–624. PubMed