Rearfoot Eversion Research Articles

Dynamic Stability In Runners With Plantar Fasciitis

Plantar fasciitis (PF) is a common running injury associated with low arch height, and excessive loading and pronation. Research has shown gait alterations in individuals with PF including increased rearfoot eversion, forefoot plantarflexion, and MTPJ dorsiflexion, and reduced center of pressure (COP) duration at the heel. Changes in kinematics and COP trajectory may affect dynamic stability. Therefore, dynamic stability as measured by time to contact (TtC) may be reduced in runners with PF. PURPOSE: To determine differences in dynamic stability during the stance phase of running in individuals with PF. METHODS: Twenty runners were separated into two groups based on injury status (1: PF; 2: healthy). Kinematic and kinetic data were collected at 200 and 1000 Hz, respectively, as participants ran at 3.5 m/s ±5%. TtC of the COP to the medial and anterior boundaries of the base of support were calculated over the stance phase. Minimum TtC values were determined for each portion of stance per trial, averaged across five trials per participant and across participants per group. Differences in TtC between groups during early, middle, and late stance were determined using one-way ANOVAs with alpha level set at 0.05. RESULTS: Group demographics were similar. TtC was similar between groups during early and late stance and different during mid-stance (Table 1). CONCLUSION: TtC was similar between runners with and without PF during early and late stance which may be related to inherent instability in transition phases. Runners with PF had reduced TtC during mid-stance suggesting a more rigid control strategy reflecting the injured state and increased potential for loss of balance.Table 1: Results for demographics and time to contact (TtC) for runners with and without plantar fasciitis (PF). * = significant difference (α=0.05).

Rearfoot and Tibial Motion during Gait Associated with Medial Tibial Stress Syndrome: A Systematic Review

PURPOSE: The purpose of this study was to confirm the kinematic characteristics of overuse leg injuries during gait through a systematic review.METHODS: Electronic databases from 1960 to 2018 were used to search studies. Physiotherapy Evidence Database Scale was used for quality of studies. Effect sizes (ES) of between-groups and its 95% confidence intervals were calculated.RESULTS: Seven studies were selected for review. The average Physiotherapy Evidence Database Scale score was 4.3 of 10-point scale. The ES for maximum rearfoot eversion from 5 studies ranged from -0.34 to 0.67 with 3 of 5 studies statistically significant. The ES of eversion excursion from 4 studies ranged from -0.24 to 2.37 and 3 of 4 studies showed statistically significant. The ES of maximum eversion velocity ranged from 0.29 to 0.38 from all of 2 studies. With abduction, the ES for abduction excursion ranged from -0.04 to 0.35, and 2 of 3 studies revealed statistically significant. The ES of maximum abduction velocity showed statistically significant with the ES of 0.23 and 0.61. However, maximum abduction from 3 studies showed non-significant with ES ranges from 0.00 to 0.62.CONCLUSIONS: The rearfoot motion (eversion) associates with overuse leg injuries during gait more than tibial motion (internal rotation).

Rearfoot and Tibial Motion during Gait Associated with Medial Tibial Stress Syndrome: A Systematic Review

PURPOSE: The purpose of this study was to confirm the kinematic characteristics of overuse leg injuries during gait through a systematic review.METHODS: Electronic databases from 1960 to 2018 were used to search studies. Physiotherapy Evidence Database Scale was used for quality of studies. Effect sizes (ES) of between-groups and its 95% confidence intervals were calculated.RESULTS: Seven studies were selected for review. The average Physiotherapy Evidence Database Scale score was 4.3 of 10-point scale. The ES for maximum rearfoot eversion from 5 studies ranged from -0.34 to 0.67 with 3 of 5 studies statistically significant. The ES of eversion excursion from 4 studies ranged from -0.24 to 2.37 and 3 of 4 studies showed statistically significant. The ES of maximum eversion velocity ranged from 0.29 to 0.38 from all of 2 studies. With abduction, the ES for abduction excursion ranged from -0.04 to 0.35, and 2 of 3 studies revealed statistically significant. The ES of maximum abduction velocity showed statistically significant with the ES of 0.23 and 0.61. However, maximum abduction from 3 studies showed non-significant with ES ranges from 0.00 to 0.62.CONCLUSIONS: The rearfoot motion (eversion) associates with overuse leg injuries during gait more than tibial motion (internal rotation).

Major factors influencing rearfoot external eversion moment during barefoot walking

BackgroundExcessive rearfoot eversion motion during walking has been considered as a risk factor for lower limb chronic injuries. External moment due to ground reaction force (GRF) is the essential cause by which the rearfoot is passively everted during walking. Research questionThis study aims to identify the key factors influencing the rearfoot external eversion moments due to the GRF during walking. MethodsFrom 3-D foot coordinates and GRF data of 29 healthy participants during walking, the rearfoot external eversion moments due to the GRF and factors composing the moment (height of the ankle joint center, mediolateral GRF, mediolateral distance of the center of pressure relative to the ankle joint center in the transverse plane, vertical GRF) were computed. ResultsThe mediolateral GRF was a key factor influencing the magnitude of the rearfoot external eversion moment just after foot contact, with which pre-contact medial foot velocity was significantly correlated. During the subsequent support phase, the mediolateral distance of the center of pressure (the application point of the vertical GRF) relative to the ankle joint center was also found to be another determinant of the magnitude of the rearfoot external eversion moment. SignificanceWe succeeded in demonstrating the specific factors that most likely explain the magnitude of the rearfoot external eversion moment during initial contact and the subsequent support phase during walking. Based on the findings, specific measures to suppress the rearfoot external eversion moment could be proposed.

A LITERATURE REVIEW AND CLINICAL COMMENTARY ON THE DEVELOPMENT OF ILIOTIBIAL BAND SYNDROME IN RUNNERS

Iliotibial Band Syndrome (ITBS) is the second leading cause of pain in runners and there are a number of theories related to its etiology. Multiple theories exist for the etiology of ITBS related symptoms including anterior-posterior friction of the IT band on the lateral femoral condyle during knee flexion and extension activities, compression of a layer of fat near the IT band distal attachment, and inflammation of the IT band bursa. The purpose of this literature review and clinical commentary was to explore the potential factors that contribute to ITBS development in runners. A literature review was performed to gather relevant evidence related to the topic and then categorized according to prospective and retrospective results. The electronic databases PubMed, EBSCOhost, CINAHL, and SportDiscus were utilized with the search terms iliotibial band, iliotibial band syndrome, iliotibial pain, and runners. The inclusion criteria included English-language, peer-reviewed journals; adult male or female runners, whether competitive or recreational with regard to mileage; subjects that either had a previous or existing diagnosis of ITBS or were at risk for developing ITBS; retrospective and prospective designs were included and the majority of studies reviewed were cohort or case-control designs. The literature was either contradictory or inconclusive to support a link between ITBS and decreased muscle strength or endurance. A weak correlation existed between strain rate of the hip abductor muscles with hip adduction and knee internal rotation, increased knee internal rotation during the stance phase of gait, and a diminished rearfoot eversion angle at heel strike. Additionally, decreased hip adduction angles during stance phase were observed in individuals without active symptoms but who had a previous history of ITBS. Finally, the female gender may be a predisposing factor. 5.

Validity and reliability of a smartphone motion analysis app for lower limb kinematics during treadmill running

ObjectiveTo investigate the validity and reliability of a smartphone application for selected lower-limb kinematics during treadmill running. DesignValidity and reliability study. SettingBiomechanics laboratory. ParticipantsTwenty healthy female runners. Main outcome measure(s)Sagittal-plane hip, knee, and ankle angle and rearfoot eversion were assessed using the Coach’s Eye Smartphone application and a 3D motion capture system. Paired t-test and intraclass correlation coefficients (ICC) established criterion validity of Coach’s Eye; ICC determined test-retest and intrarater/interrater reliability. Standard error of measurement (SEM) and minimal detectable change (MDC) were also reported. ResultsSignificant differences were found between Coach’s Eye and 3D measurements for ankle angle at touchdown and knee angle at toe-off (p < 0.05). ICCs for validity of Coach’s Eye were excellent for rearfoot eversion at touchdown (ICC = 0.79) and fair-to-good for the other kinematics (range 0.51–0.74), except for hip at touchdown, which was poor (ICC = 0.36). Test-retest (range 0.80–0.92), intrarater (range 0.95–0.99) and interrater (range 0.87–0.94) ICC results were excellent for all selected kinematics. ConclusionCoach’s Eye can be used as a surrogate for 3D measures of knee and rearfoot in/eversion at touchdown, and hip, ankle, and rearfoot in/eversion at toe-off, but not for hip and ankle at touchdown or knee at toe-off. Reliable running kinematics were obtained using Coach’s Eye, making it suitable for repeated measures.

Effects of load carriage on biomechanical variables associated with tibial stress fractures in running

BackgroundMilitary personnel are required to run while carrying heavy body-borne loads, which is suggested to increase their risk of tibial stress fracture. Research has retrospectively identified biomechanical variables associated with a history of tibial stress fracture in runners, however, the effect that load carriage has on these variables remains unknown. Research questionWhat are the effects of load carriage on running biomechanical variables associated with a history of tibial stress fracture? MethodsTwenty-one women ran at 3.0 m/s on an instrumented treadmill in four load carriage conditions: 0, 4.5, 11.3, and 22.7 kg. Motion capture and ground reaction force data were collected. Dependent variables included average loading rate, peak absolute free moment, peak hip adduction, peak rearfoot eversion, and stride frequency. Linear mixed models were used to asses the effect of load carriage and body mass on dependent variables. ResultsA load x body mass interaction was observed for stride frequency only (p = 0.017). Stride frequency increased with load carriage of 22.7-kg, but lighter participants illustrated a greater change than heavier participants. Average loading rate (p < 0.001) and peak free moment (p = 0.015) were greater in the 22.7-kg condition, while peak rearfoot eversion (p ≤ 0.023) was greater in the 11.3- and 22.7-kg conditions, compared to the unloaded condition. Load carriage did not affect peak hip adduction (p = 0.67). SignificanceParticipants adapted to heavy load carriage by increasing stride frequency. This was especially evident in lighter participants who increased stride frequency to a greater extent than heavier participants. Despite this adaptation, running with load carriage of ≥11.3-kg increased variables associated with a history of tibial stress fracture, which may be indicative of elevated stress fracture risk. However, the lack of concomitant change amongst variables as a function of load carriage may highlight the difficulty in assessing injury risk from a single measure of running biomechanics.

Do maximalist shoes mitigate risk factors for tibial stress fractures better than stability or flexible (marketed as minimalist) shoes?

Background: Tibial stress fractures (TSF) are a common running related injury. Specific risk factors include increased rearfoot eversion and increased vertical instantaneous and average loading rates (VILR and VALR, respectively). Since these risk factors are mechanical in nature, certain types of running shoes may be able to reduce these risk factors for TSF. The objective of this study was to determine the effects of maximalist, stability, and flexible (commercially marketed as minimalist) running shoes on specific risk factors for TSF in male and female runners.Methods: Fourteen recreation runners were recruited for this study, 7 males and 7 females. A 14-camera motion capture system and three force plates were used to capture each subject’s kinematics and kinetics. Subjects ran in maximalist (Hoka Bondi 5), stability (Nike Structures), neutral (Nike Pegasus), and flexible (Nike Free) shoes.Results: Among males there was a significant increase in ankle internal rotation ROM in the maximalist shoe compared to neutral. There was also a significant decrease in ankle internal rotation ROM in the flexible shoe compared to neutral. Among females there was a significant reduction in peak ankle eversion and ankle eversion ROM.Conclusions: The results of this study suggest that the maximalist shoes may reduce the pronation component of TSF risk factors in female runners. The maximalist shoes were able to reduce the peak ankle eversion and ROM. This is likely due to the specific design mechanism of the maximalist shoe to control foot motion.

Differences in foot muscle morphology and foot kinematics between symptomatic and asymptomatic pronated feet.

This study aimed to determine the differences in foot muscle morphology and 3D multisegmental foot kinematics during walking between symptomatic and asymptomatic individuals with pronated feet (pronators) in a physically active population. A total of 30 young physically active adults with pronated feet participated in this study, with 15 of them having recurring overuse injuries in the lower extremity in the 6months prior to the test. A pronated foot was identified as having a foot posture index score between 6 and 12. An ultrasound system was used to measure the cross-sectional area and thickness of foot muscles of interest, including peroneus muscles, flexor digitorum longus and brevis, and abductor hallucis. Foot kinematic data during walking was collected using a 3D motion capture system incorporating the Oxford Foot Model. The symptomatic pronators demonstrated smaller cross-sectional area of flexor digitorum longus and abductor hallucis, and thinner peroneus muscles and abductor hallucis than their asymptomatic counterparts. The symptomatic pronators also displayed higher forefoot peak abduction during the stance phase of walking. There are differences in both extrinsic and intrinsic foot muscle morphology between symptomatic and asymptomatic pronators in a physically active adult population. Strengthening foot muscles may contribute to injury prevention in pronators. Large forefoot abduction instead of large rearfoot eversion during walking might be the indicator of pain in physically active pronators. Findings of this study may have implications on the underlying mechanisms of overuse injuries in individuals with pronated feet.

Is the Knee Adduction Moment reduced by excessive rearfoot eversion in flatfeet?

Is the Knee Adduction Moment reduced by excessive rearfoot eversion in flatfeet?

Effects of a foot orthosis inspired by the concept of a twisted osteoligamentous plate on the kinematics of foot-ankle complex during walking: A proof of concept

It has been suggested that the foot acts as a twisted osteoligamentous plate to control pronation and facilitate supination during walking. The aim of this study was to investigate the effect of an orthosis inspired by the concept of a foot’s twisted osteoligamentous plate on the kinematics of foot-ankle complex. Thirty-five subjects underwent a kinematic assessment of the foot-ankle complex during walking using three different orthoses: (1) Twisted Plate Spring (TPS) orthosis: inspired by the concept of a twisted osteoligamentous plate shape and made with a spring-like material (carbon fiber); (2) Flat orthosis: control orthosis made of a non-elastic material with a non-inclined surface; and (3) Rigid orthosis: control orthosis made of a non-elastic material, with the same shape of the TPS. Repeated measures analyses of variance demonstrated that the TPS reduced the duration and magnitude of rearfoot eversion (p ≤ 0.03), increased rearfoot inversion relative to shank (p < 0.01), increased forefoot eversion relative to rearfoot (p < 0.01), and increased peak of plantar flexion of forefoot relative to rearfoot during the propulsive phase (p = 0.01) compared to Flat orthosis. The effects of the TPS were different from the Rigid orthosis, demonstrating that, alongside shape, material properties were a determinant factor for the obtained results. The findings of this study help clarify the role of a mechanism similar to a twisted osteoligamentous plate on controlling foot pronation and facilitating supination during the stance phase of walking.

Relationship between Stance Frontal Plane Kinematics and Initial Impact forces in Runners: Asymmetry Implications

Rearfoot eversion (REV) and contralateral pelvis drop (CPD) play a crucial role in force absorption at impact during running. Controlling and adequately absorbing the repetitive vertical ground reaction force (vGRF) at impact is essential in injury prevention. PURPOSE: This study aimed to examine the relationships between vGRF and REV, and vGRF and CPD bilaterally in collegiate runners. METHODS: Eleven asymptomatic (5 females, 6 males) NCAA Division II cross country runners (age, 19.1 ± 1.1 yrs; height, 174.2 ± 11.2 cm; mass 62.2 ± 6.2 kg; 38.3 ± 15.9 miles/wk, treadmill speed, 3.6 ± 0.5 m/s) underwent 3D motion analysis during a 7 minute steady state run on an instrumented treadmill. vGRF, REV and CPD were evaluated bilaterally for association via Pearson Correlation coefficients, p<0.05. RESULTS: Mean (+SD) peak angles of REV and CPD, and vGRF during left stance were 3.6 ± 6.5°, -5.4 ± 3.8°, and 1.8 ± 0.6 body weights (BW), respectively. Mean peak angles of REV and CPD, and vGRF during right stance were 2.51 ± 2.5°, -4.9 ± 4.9°, and 1.6 ± 0.4 BW, respectively. Significant high negative correlation was found for REV and vGRF during left stance [r (9) = -.967, p=0.03] while CPD and vGRF during right stance were significantly highly positively correlated [r (9) .714, p=0.02]. CONCLUSION: Despite the low number of subjects, we conclude that frontal plane kinematics are associated with impact force magnitude during running, and the associations appear to be asymmetrical necessitating a bilateral examination of running mechanics.

The biomechanical difference between running with traditional and 3D printed orthoses

ABSTRACTRunning-related injuries have been associated with excessive foot pronation and high vertical loading rates. Traditional plaster-molded (TPM) foot orthoses are commonly prescribed to minimize these atypical biomechanical patterns. Recently, 3D printed (3DP) orthoses have become popular, yet the functional difference between these two types of orthoses remains unknown. Therefore, this study compared running biomechanics and perceived comfort during treadmill running in three orthotic conditions: 3DP orthoses, TPM orthoses, and a no-orthoses control condition (CON). Thirteen female asymptomatic runners with excessive foot pronation were recruited. Rearfoot eversion angle and velocity (at initial contact and peak) during stance, vertical loading rates, and perceived comfort were compared. Results showed lower peak rearfoot eversion angles during running with TPM (p=0.001, d=0.38) or 3DP orthoses (p=0.002, d=0.24) than CON. No differences were observed in other biomechanical parameters among the three conditions (p>0.05). Running with TPM (p≤0.001, d=1.74–1.82) and 3DP orthoses (p<0.003, d=1.06–1.34) resulted in better perceived comfort in “medial-lateral control” and “heel cushioning” than CON. There were no statistical differences in all parameters between TPM and 3DP orthoses. The present findings indicate improved comfort during running with TPM or 3DP orthoses, which hinted 3DP orthoses could be a viable alternative to TPM orthoses for clinical practice.

THE EFFECT of KINESIO TAPE® on STATIC FOOT POSTURE, PLANTAR PRESSURE, and REARFOOT MOTION in INDIVIDUALS with PRONATED FEET

Kinesio Tape® (KT) is an elastic therapeutic tape that is applied to the skin for treatment of sport-related injuries. Its application has been purported to facilitate the neuromuscular system, thus altering skeletal muscle activity to increase joint range of motion and improve performance. Due to its proposed therapeutic effect, KT may benefit individuals with excess foot pronation in order to decrease pain and improve function. Unfortunately, current research regarding the ability of KT to alter foot biomechanics is limited. The purpose of this study was to determine if the application of KT to the ankle and lower leg would alter static foot posture, plantar pressure, and foot motion during walking in individuals with foot pronation. Prospective Cohort Study. Thirty participants (10M/20F) were recruited for this study. Each participant had their dorsal arch height and midfoot width measured prior to the application of the KT. In addition, their dynamic rearfoot eversion and plantar pressure was recorded during walking using an electrogoniometer and plantar pressure system. After these measurements were collected, KT was applied to their right foot and lower leg in order to attempt to facilitate activity in the posterior tibialis muscle. After applying the tape, the above measurements were repeated. None of the variables measured were statistically significantly different between the pre-test and post-test. Application of KT did not result in a change in static foot posture, plantar pressure, and frontal plane rearfoot motion during walking. As such, KT cannot be recommended as a treatment for reducing excessive foot pronation where such a goal would be beneficial. Level 3.

Ankle Joint Kinetics in Runners with Medial Tibial Stress Syndrome

Medial tibial stress syndrome (MTSS) is a common overuse running injury. While numerous studies have reported abnormal ankle kinematics in runners with MTSS, to date, no studies have evaluated ankle kinetics in this population. PURPOSE: To compare ankle kinetics in runners with and without MTSS. METHODS: Participants included eight runners with MTSS (sex: 7M/1F; age: 35 ± 11.3 years) and eight matched controls (CON; sex: 7M/1F; age: 35 ± 8.7 years). Kinematics and ground reaction forces were recorded while participants ran overground. Sagittal plane kinetics were calculated about an axis connecting the malleoli while frontal plane kinetics were calculated about an axis approximating the 23° medially deviated and 42° inclined orientation of the subtalar joint. Joint work was calculated by integrating the joint power curves. Paired t-tests were used to compare peak moments, powers, and work between MTSS and CON groups. RESULTS: Neither peak plantar flexor (MTSS: 2.14 ± 0.53, CON: 2.24 ± 0.57 Nm/kg) nor peak invertor (MTSS: 1.04 ± 0.34, CON: 1.16 ± 0.32 Nm/kg) moments were different between groups (p = .720, p = .472, respectively). There were no differences in sagittal plane powers or work between groups. In the frontal plane, the MTSS group demonstrated lower peak positive power (MTSS: 1.97 ± 0.38, CON: 3.05 ± 1.12 W/kg, p = .021), and performed less negative (MTSS: -0.09 ± 0.02, CON: -0.16 ± 0.07 J/kg, p = .032), positive (MTSS: 0.14 ± 0.03, CON: 0.22 ± 0.07 J/kg, p = .039), and total (MTSS: 0.23 ± 0.06, CON: 0.37 ± 0.15 J/kg, p = .032) work. CONCLUSIONS: Compared to healthy individuals, runners with MTSS are not able to generate as much energy to invert their foot during late stance. This may explain why previous studies have observed runners with MTSS have prolonged rearfoot eversion during stance.Figure 1: Frontal plane joint moments (A) and powers (B). The solid line represents the CON group and the dotted line represents the MTSS group. Error bars show one standard deviation above and below the mean curve for the CON group.

Ankle Joint and Rearfoot Biomechanics During Toe-In and Toe-Out Walking in People With Medial Compartment Knee Osteoarthritis.

Toe-in and toe-out walking are 2 strategies that have been shown to be effective in reducing the knee adduction moment in people with knee osteoarthritis. However, despite a positive biomechanical impact on the knee, altering foot rotation may impart unintended forces or joint positions on the ankle that could impact joint health. The kinematic and kinetic changes at the ankle during toe-in or toe-out walking have yet to be examined. To examine ankle/rearfoot biomechanics during toe-in and toe-out walking in those with knee osteoarthritis. Single-session repeated measures design to compare ankle biomechanics during walking with 4 different foot rotations. University motion analysis laboratory. A convenience sample (N = 15) of males and females with a diagnosis of medial knee osteoarthritis confirmed by radiographs. Participants walked in 4 conditions guided by real-time biofeedback: (1) toe-in (+10°), (2) zero rotation (0°), (3) toe-out (-10°), and (4) toe-out (-20°). Ankle and rearfoot kinematics and kinetics were examined during barefoot over-ground walking. Ankle joint angles, moments, moment impulses, and foot rotation. Overall, toe-in compared to toe-out walking decreased (P = .03) peak rearfoot eversion (toe-in = -1.6°; 10° toe-out = -3.7°; 20° toe-out = -4.1°). Toe-in compared to toe-out walking also increased rearfoot inversion at initial contact (7.4° vs 3.1° at 10° toe-out and 1.9° at 20° toe-out; P < .001) and frontal plane rearfoot angle excursion (9.0° vs 6.8° at 10° toe-out and 6.0° at 20° toe-out; P < .006). Toe-in compared to all other conditions increased peak external ankle inversion moments (0.04 Nm/kg vs 0.02 Nm/kg at 0°, 0.02 Nm/kg at 10° toe-out, and 0.01 Nm/kg at 20° toe-out; P < .003). Toe-in and toe-out walking require different ankle/rearfoot biomechanics, though no differences in discomfort were observed. Longer-term studies are required to properly assess these relationships in knee osteoarthritis populations. IV.

The influence of prolonged running and footwear on lower extremity biomechanics

The effect of maximal isolated muscle and cardiovascular fatigue on lower extremity biomechanics during running has been investigated extensively. However, the majority of runners do not run to exhaustion regularly. Consequently, research and industry are interested in biomechanical changes over the course of a typical prolonged run and how footwear technology may affect them. This study investigated the influence of neutral and stability footwear worn during a 42-minute prolonged treadmill run on lower extremity biomechanics. Fourteen male rearfoot runners completed two prolonged running sessions where they ran for 21 minutes on a force instrumented treadmill in a neutral shoe (baseline run). Participants then changed into another neutral shoe of the exact same construction but a different color or into a stability shoe and ran for a further 21 minutes (intervention run). Three-dimensional kinematics and kinetics were measured at the beginning and end of each 21-minute running period. Main effects for time were observed at the hip, knee, and ankle during both the baseline and intervention runs. Particularly, increased knee flexion and rearfoot eversion observed during mid-stance may exhibit a strategy to reduce the effective mass and minimize joint loads applied to the foot and knee. No main effects for footwear condition were found in lower extremity biomechanics. However, individual responses to the neutral and stability shoe conditions were observed. Running shoe design should: (1) focus on both acute and prolonged changes in lower extremity biomechanics at the individual level, and (2) further investigate the use of materials/architecture that allow runners to stay within their initial (baseline) preferred motion path and/or provide greater support when preferred motion path changes throughout a prolonged run.

Coordination Among Shank, Rearfoot, Midfoot and Forefoot Kinematic Movement During Gait in Individuals With Hallux Valgus.

An important step in the management of hallux valgus is the objective analysis of foot mechanics in dynamic conditions. However, the manner which hallux valgus affects the foot motion is poorly understood. Moreover, hallux valgus deformity may affect foot intersegmental coordination patterns. The purpose of this study was to investigate the relative motion and intersegmental foot coordination patterns, considering the midfoot, during gait in individuals with hallux valgus. Fifteen females with hallux valgus and 13 females without hallux valgus were recruited in this study. Three-dimensional positional data during gait were collected using a motion capture system and analyzed using a multisegment foot model and an analysis software. Intersegmental foot coordination patterns were assessed using a modified vector-coding technique. In individuals with hallux valgus, the rearfoot was significantly more everted throughout stance, and forefoot motion during late stance was significantly increased. In intersegmental coordination patterns, individuals with hallux valgus exhibited excessive mobility of the rearfoot relative to the midfoot segment during midstance and increased anti-phase motion between rearfoot and midfoot segments during late stance. Excessive rearfoot eversion and altered intersegmental coordination patterns between rearfoot and midfoot may decrease the proper rigidity of the foot and lead to forefoot hypermobility during late stance in individuals with hallux valgus.

Foot Kinematics Differ Between Runners With and Without a History of Navicular Stress Fractures.

Background:A navicular stress fracture (NSF) is a common and high-risk injury in distance runners. It is not clear whether there are differences in foot structure and function between runners who have and those who have not sustained an NSF.Purpose/Hypothesis:This study compared foot structure, range of motion, and biomechanics between runners with a history of unilateral NSFs and runners who had never sustained this injury. The hypothesis was that runners with a history of NSFs will have less dorsiflexion and subtalar range of motion in a clinical examination and greater rearfoot eversion and higher eversion velocity while running than either the noninvolved feet or healthy controls.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Seven runners who sustained an NSF were matched with 7 controls without this injury history. Participants underwent a clinical orthopaedic examination, followed by a 3-dimensional running gait analysis. Clinical examination variables, foot kinematics, and ground-reaction forces were compared between injured and noninjured feet within the NSF group and between the NSF group and control group.Results:The NSF group demonstrated less plantar flexion on the clinical examination than the control group (P = .034, effect size [ES] = 0.69). The involved feet of the NSF group demonstrated greater rearfoot eversion excursion, greater eversion velocity, and reduced forefoot abduction excursion than either the noninvolved feet of the NSF group (P = .015, ES = 1.73; P = .015, ES = 1.86; and P = .015, ES = 0.96, respectively) or the control group (P = .012, ES = 1.40; P = .016, ES = 0.49; and P = .005, ES = 1.60, respectively).Conclusion:There are differences in foot kinematics but not ground-reaction forces, foot structure, or passive range of motion between runners who have and those who have not sustained an NSF. Runners who demonstrate increased rearfoot eversion and reduced forefoot abduction during stance may be more at risk for developing NSFs.

Which is the best predictor of excessive hip internal rotation in women with patellofemoral pain: Rearfoot eversion or hip muscle strength? Exploring subgroups

BackgroundPatellofemoral pain (PFP) has been linked to increased patellofemoral joint stress as a result of excessive hip internal rotation. Lower hip strength and/or excessive rearfoot eversion have been used to explain such altered movement pattern; however, it is unknown which one is the best predictor of excessive hip internal rotation. Research questionTo investigate if peak rearfoot eversion and/or peak concentric hip abductor strength can predict peak hip internal rotation during stair ascent in women with PFP. MethodsThis cross-sectional study included thirty-seven women with PFP which underwent three-dimensional kinematic analysis during stair ascent and hip abductor strength analysis in an isokinetic dynamometer. A forced entry linear regression model analysis was carried out to determine which independent variables present the best capability to predict the hip internal rotation. ResultsPeak concentric hip abductor strength significantly predicted peak hip internal rotation during stair ascent (R2 = 0.27, p = 0.001). Peak rearfoot eversion did not predict peak hip internal rotation during stair ascent (R2 < 0.01, p = 0.62). A Post-hoc analysis was conducted to explore if a subgroup with excessive rearfoot eversion would predict hip internal rotation. Based on a previous reported cut-off point, 48.6% of the participants were classified as excessive rearfoot eversion. For the subgroup with excessive rearfoot eversion, peak concentric hip abductor strength and peak rearfoot eversion significantly predicted peak hip internal rotation during stair ascent (R2 = 0.26, p = 0.02; R2 = 0.42, p = 0.003, respectively). For non-excessive rearfoot eversion subgroup, peak concentric hip abductor strength significantly predicted peak hip internal rotation during stair ascent (R2 = 0.53; p < 0.001); and peak rearfoot eversion did not (R2 = 0.01; p = 0.65). SignificanceFindings indicate that hip muscle strength seems to be related with hip internal rotation in all women with PFP. Rearfoot eversion seems to be related with hip internal rotation only in a subgroup with excessive rearfoot eversion.