Ankle Characteristics Research Articles

Post-Operative Lucency Formation Amongst Stemmed vs Non-Stemmed Total Ankle Arthroplasty Constructs

Category: Ankle Arthritis; Ankle; Hindfoot Introduction/Purpose: Current available total ankle replacement constructs offer either proximal projecting pegs (non- stemmed) in various shapes or large stem (stemmed) designs to the superior aspect of the tibia component. Each design offers inherent stability and unique function. Periprosthetic radiolucency can develop post-operatively and lead to adverse effects. However, the incidence and clinical significance of lucency formation amongst stemmed and non-stemmed constructs is poorly understood. Methods: A retrospective radiographic and chart analysis was performed of 256 patients, under a single orthopedic practice, who underwent primary TAA between 2013-2019 with one of 3 total ankle systems. Pre-operative ankle characteristics, intraoperative procedures, as well as post-operative angles, lucency formation, region of lucency formation, and patient outcomes were analyzed. Results: Patients' mean age 65.5 yrs., male n=126 and female n=127, a mean follow-up of 24.3 months for our patient cohort. A total of 149 stemmed and 107 non-stemmed constructs were analyzed. Incidence of periprosthetic tibial lucency formation 33.2%, stemmed implants 10.0%, and 65.4% for non-stemmed implant (p value 0.00001). Conclusion: This paper describes the incidence of periprosthetic formation amongst a stemmed and non-stemmed total ankle arthroplasty cohort. Statistical significance was found when analyzing stemmed vs. non-stemmed incidence of radiolucency formation, this did not correlate with increased incidence of post-operative complications.

Foot and ankle characteristics associated with fear of falling and mobility in community-dwelling older people: a cross-sectional study.

Fear of falling is multifactorial in etiology and is associated with falls. It has been demonstrated that foot problems increase the risk of falls in older people. Therefore, the objective of this study was to investigate the associations of foot and ankle characteristics with fear of falling and mobility in community-dwelling older people. One hundred and eighty-seven community-dwelling older adults (106 females) aged 62-90 years (mean 70.5 ± 5.2) from Isfahan, Iran, were recruited. Foot and ankle characteristics (including foot posture, range of motion, muscle strength, deformity, tactile sensation, pain and dynamic function), fear of falling (Fall Efficacy Scale International) and mobility (Timed Up and Go Test) were measured. Two multivariate linear regression analyses identified variables independently associated with fear of falling and mobility. Linear regression analysis revealed that less ankle plantarflexor muscle strength, greater pressure-time integral, foot pain, and reduced tactile sensitivity of the ankle were significantly and independently associated with increased fear of falling. The total variance explained by the model was 59%. Less ankle plantarflexor muscle strength, greater pressure-time integral, and slower centre of pressure velocity were significantly and independently associated with poorer mobility. The total variance explained by the model was 48%. Several foot and ankle characteristics are associated with fear of falling and mobility in older people. Targeting these modifiable risk factors may play a role in reducing fear of falling and enhancing mobility performance in this population.

Structural and functional foot and ankle characteristics associated with falls in older people

Falls affect approximately one in three older people, and foot problems are amongst the modifiable potential risk factors. what are the associations between foot and ankle functional and structural characteristics with falls in community-dwelling older adults? One hundred eighty-seven community-dwelling older adults (106 females) aged 62-90 years (mean 70.5 ± 5.2) from Isfahan, Iran were recruited. Foot and ankle structure and function (including foot posture, range of motion, muscle strength, deformity, pain and plantar loading patterns during walking) were measured. Fall history was documented in the preceding year. Univariate analyses compared fallers and non-fallers on all variables to determine significant differences and logistic regression analysis identified variables independently associated with falls. Seventy-four participants (39.9 %) had experienced a fall in the previous year. Logistic regression analysis revealed that less first metatarsophalangeal joint extension (odds ratio 0.82, 95 % CI 0.73-0.91), less plantarflexor muscle strength (odds ratio 0.29, 95 % CI 0.15-0.55), greater pressure-time integral in the medial forefoot (odds ratio 2.65, 95 %CI 1.10-6.38), greater center of pressure velocity in the forefoot (odds ratio 1.27, 95 % CI 1.07-1.49) and greater foot pain (odds ratio 1.09, 95 % CI 1.02-1.16) were significantly and independently associated with falls after accounting for physiological falls risk factors. We have identified several structural and functional foot and ankle characteristics associated with falling in older people. Future development of interventions to help prevent or treat these potentially modifiable risk factors may help decrease the risk of falling in this population.

Foot and Ankle Characteristics in Gout: A Systematic Review

Objectives: Gout has a predilection for the foot and ankle, but the impact of gout has limited presence in the literature. The aim of this systematic review was to synthesise existing literature which has investigated the characteristics of foot and ankle involvement in gout; identifying consensus and highlighting areas for further study. Methods: Studies were included if they were published in English and involved participants over 18 years of age with gout, and presented original findings relating to outcome measures associated with the foot and ankle. Methodological quality was assessed using a modified version of the Quality Index Tool. Results. Of 707 studies identified, 16 met the inclusion criteria and were included in this review. The mean (range) quality score was 68.1% (38.9%-88.9%). Compared to controls, participants with gout reported higher levels of activity limitation, foot-related pain and disability and walked more slowly. Plain radiography, dual-energy Computer Tomography and diagnostic ultrasound consistently demonstrated pathological features of gout in the first metatarsophalangeal joint and Achilles tendon. However, studies offered limited quality, particularly around recruitment strategies, validity and potential impact of confounding factors, making definitive statements difficult. Conclusions: This systematic review highlights the negative impact of gout on the structure and function of the foot and ankle causing significant impairment and disability. To effectively guide management, improvements in methodological quality are recommended.

Musculoskeletal profile of the hip, ankle and foot characteristics of cadets from Brazilian Navy academy

Musculoskeletal profile of the hip, ankle and foot characteristics of cadets from Brazilian Navy academy

A descriptive study comparing the foot and ankle structure and dynamics in children with cerebral palsy and children without cerebral palsy

This study will conduct to investigate the effects of foot and ankle characteristics on balance and function in children with Cerebral Palsy and healthy children. A total of 37 children; 17 healthy subjects and 20 children who diagnosed with Cerebral Palsy will included in the study. All of the childrens’ foot postures will determine with the foot posture index, navicular drop test, navicular height and arc height ratio calculation. In addition to these procedures, static and dynamic pedobarographic analysis will performe. Postural sway will measure on the stabilometric platform. Balance and functional performance will measure by using; the pediatric balance scale, pediatric reach test and timed performance tests such as the tind up and go test, time up-down stair test, ten meter walking test will performe. The differences of these parameters between two groups and the relationship between foot posture parameters, balance and functional tests will investigate.

Variable Lower Limb Alignment of Clinical Measures With Digital Photographs and the Footscan Pressure System

This study examines the effect of the lower limb misalignment and its possible compensatory effect on plantar pressure in a normal population. The aim of this paper is to present a structured method for the analysis of posture and its changes using a standardized digital photography technique and plantar pressure measuring device. Cohort. Laboratory. A total of 200 adult volunteers between 18 and 22 years of age who had no current symptoms of pain and foot or ankle pathology participated in the study. The gold standard measure of lower limb alignment with weight-bearing status is the mechanical axis and their angles using Image J software. Structural and functional measurements of the same foot were taken using a plantar pressure measuring device. In this study, 5 alignment (thigh, knee, leg, ankle, and foot) characteristics were measured on the lower limb using the 2 techniques, and, additionally, the foot contact area, peak pressure, foot axis, rearfoot angle, and subtalar joint flexibility score were analyzed in 10 different regions of the foot. This study has shown a reasonable correlation between digitalized measurements and plantar pressures values. Quadriceps angle affected midfoot impulse, foot axis angle, subtalar joint minimum angle, and rearfoot angle positively. Subtalar joint flexibility scores were analyzed in 10 different regions of the foot. There was a positive correlation between rearfoot angle and quadriceps angle (P = .009, r = .261). Results of both methods show that they endorse each other. The posture of the standing feet may have influence on lower limb alignment. Currently, there are no studies carried out by using digital photogrammetry and foot scan. The authors claim that patient-friendly digital photogrammetry would have a positive contribution to the monitoring of patients, even including new ones in the treatment programs, reducing any possible loss in the personal and national economy.

Spectral analysis of pathological gait characteristics of patients suffering from Parkinson disease and Strokes

Strokes and Parkinson's disease (PD) are the current leading cause of severe, and long-term disability prevailing in Sri Lanka. Detection of gait characteristics has become an interesting field of biomechanics that provides useful information in the management of the above two diseases. The objective of the study presented in this paper is to establish a technique for the gait detection of Stroke and PD patients using Discrete Fourier Transforms (DFT). Twenty four patients with PD and Stroke and five healthy controls were made to perform a series of movements which were measured using Kinect (a motion detection sensor produced by Microsoft). All the participants were recruited from the National Hospital Sri Lanka (NHSL). The Kinect device provided x, y, z coordinates of the ankle, knee, and hip joints. Ankle, knee, and hip joint angle characteristics have been analyzed in the frequency domain, and abnormal gait of Stroke and PD patients has been identified using harmonic coefficients. Experimental results and analysis indicate that both Stroke and PD patients have significant amplitude values for the first few harmonics relative to healthy controls. This result conforms with the shorter stride length property of Stroke and PD patients. For therapeutic interventions to improve gait performances, consideration should be given to both the severity of the disease and the lower limb involvement of the disease. Results conclude that the proposed method can accurately visualize the abnormality in the gait of Stroke and PD patients with sufficient accuracy.

Associations of foot and ankle characteristics with knee symptoms and function in individuals with patellofemoral osteoarthritis

BackgroundFoot and ankle characteristics are associated with patellofemoral pain (PFP) and may also relate to patellofemoral osteoarthritis (PFOA). A greater understanding of these characteristics and PFOA, could help to identify effective targeted treatments.ObjectivesTo determine whether foot and ankle characteristics are associated with knee symptoms and function in individuals with PFOA.MethodsFor this cross-sectional study we measured weightbearing ankle dorsiflexion range of motion, foot posture (via the Foot Posture Index [FPI]), and midfoot mobility (via the Foot Measurement Platform), and obtained patient-reported outcomes for knee symptoms and function (100 mm visual analogue scales, Anterior Knee Pain Scale [AKPS], Knee injury and Osteoarthritis Outcome Score, repeated single step-ups and double-leg sit-to-stand to knee pain onset). Pearson’s r with significance set at p < 0.05 was used to determine the association between foot and ankle charateristics, with knee symptoms and function, adjusting for age.Results188 participants (126 [67%] women, mean [SD] age of 59.9 [7.1] years, BMI 29.3 [5.6] kg/m2) with symptomatic PFOA were included in this study. Lower weightbearing ankle dorsiflexion range of motion had a small significant association with higher average knee pain (partial r = − 0.272, p < 0.001) and maximum knee pain during stair ambulation (partial r = − 0.164, p = 0.028), and lower scores on the AKPS (indicative of greater disability; partial r = 0.151, p = 0.042). Higher FPI scores (indicating a more pronated foot posture) and greater midfoot mobility (foot mobility magnitude) were significantly associated with fewer repeated single step-ups (partial r = − 0.181, p = 0.023 and partial r = − 0.197, p = 0.009, respectively) and double-leg sit-to-stands (partial r = − 0.202, p = 0.022 and partial r = − 0.169, p = 0.045, respectively) to knee pain onset, although the magnitude of these relationships was small. The amount of variance in knee pain and disability explained by the foot and ankle characteristics was small (R2-squared 2 to 8%).ConclusionsLower weightbearing ankle dorsiflexion range of motion, a more pronated foot posture, and greater midfoot mobility demonstrated small associations with worse knee pain and greater disability in individuals with PFOA. Given the small magnitude of these relationships, it is unlikely that interventions aimed solely at addressing foot and ankle mobility will have substantial effects on knee symptoms and function in this population.Trial registrationThe RCT was prospectively registered on 15 March 2017 with the Australia and New Zealand Clinical Trials Registry (ANZCTRN12617000385347).

Objectively Assessed Foot and Ankle Characteristics in Patients With Systemic Lupus Erythematosus: A Comparison With Age- and Sex-Matched Controls.

To objectively identify foot and ankle characteristics in patients with systemic lupus erythematosus (SLE) compared to age- and sex-matched controls. A total of 54 patients with SLE and 56 control participants attended a study visit designed to comprehensively assess the foot and ankle. Objectively assessed foot characteristics included muscle strength, joint motion, foot posture, foot problems, protective sensation, vibration perception threshold (VPT), ankle brachial index (ABI), plantar pressure, and spatiotemporal gait characteristics. Self-reported measure of foot pain and impairment were also assessed using a 100-mm foot pain visual analog scale. Data were analyzed using regression models. Plantar pressure and gait models were adjusted for walking velocity, body mass index, and foot pain. Compared to controls, participants with SLE had lower muscle force for plantarflexion, dorsiflexion, inversion, and eversion (all P < 0.001), higher foot posture indices (P = 0.007), higher foot problem scores (P = 0.001), higher VPT (P = 0.001), and more frequent abnormal ABI (odds ratio [OR] 3.13, P = 0.044). Participants with SLE also had lower peak pressure and higher pressure time integrals for all foot regions (all P < 0.001), lower step and stride length, velocity, and cadence, and higher step, swing, stance, and single and double support times compared to controls (all P < 0.001). Compared to controls, participants with SLE also reported greater foot pain (P < 0.001). Patients with SLE experience a wide range of foot symptoms. This study has provided objective evidence of foot and ankle disease in patients with SLE, including reduced muscle strength and altered gait patterns when compared to controls. This highlights the importance of foot health assessments as part of SLE management.

Kinematic foot types in youth with pes planovalgus secondary to cerebral palsy

BackgroundKinematic variability of the foot and ankle segments exists during ambulation among individuals with pes planovalgus (PPV) secondary to cerebral palsy (CP). Clinicians have previously recognized such variability through classification schemes to identify subgroups of individuals, but have been unable to identify kinematic foot types. Research questionThe purpose of this work was to identify kinematic foot types among children with PPV secondary to CP using 3-dimensional multi-segment foot and ankle kinematics during gait as inputs for principal component analysis (PCA) and K-means cluster analysis. MethodsIn a single assessment session, multi-segment foot and ankle kinematics using the Milwaukee Foot Model (MFM) were collected in 31 children/adolescents with pes planovalgus (49 feet) and 16 typically developing (TD) children/adolescents (31 feet). PCA was used as a data reduction technique on 34 kinematic variables. K-means cluster analysis was performed on the identified principal components (PCs) and one-way analyses of variance (ANOVA) was done to determine the effect of subgroup membership on PC scores. ResultsThe PCA reduced the kinematic variables to seven PCs which accounted for 91% of the total variance. Six distinct kinematic foot types were identified by the cluster analysis. The foot types showed unique kinematic characteristics in both the hindfoot and forefoot. SignificanceThis study provides further evidence of kinematic variability in the foot and ankle during ambulation associated with pes planovalgus secondary to CP. The specific contributions of the hindfoot and forefoot would not have been detected using a single segment foot model. The identification of kinematic foot types with unique foot and ankle characteristics has the potential to improve treatment since patients within a foot type are likely to benefit from similar intervention(s).

Foot and ankle characteristics and dynamic knee valgus in individuals with patellofemoral osteoarthritis

Study designControlled laboratory study; cross-sectional design.BackgroundFoot and ankle characteristics and dynamic knee valgus differ in people with and without patellofemoral (PF) pain. However, it is unknown if these characteristics are evident in people with PF osteoarthritis (OA), compared to pain-free older adults.ObjectivesTo compare foot and ankle mobility, foot posture and dynamic knee valgus, measured as the frontal plane projection angle (FPPA) during single-leg squatting, between individuals with and without PFOA.MethodsFifty-one participants with PFOA (66% women, mean ± SD age 57 ± 10 years, body mass index (BMI) 27 ± 6 kg/m2), and 23 controls (56% women, age 56 ± 9 years, BMI 24 ± 4 kg/m2) had ankle dorsiflexion measured using the knee-to-wall test, foot mobility calculated as the difference in midfoot height or width between non-weightbearing and weightbearing, and static foot posture characterized utilizing the Foot Posture Index. Peak FPPA was determined from video recordings while participants performed 5 single-leg squats. Linear regressions examined between-groups relationships for foot and ankle characteristics and the FPPA.ResultsThe PFOA group had less ankle dorsiflexion (odds ratio 6.7, 95% confidence interval 2.46–18.2), greater midfoot height mobility (5.2, 1.78–15.14) and width mobility (4.3, 1.33–14.39), and greater foot mobility magnitude (8.4, 2.32–30.69) than controls. There was no difference in FPPA (knee valgus angle) between groups (15, 0.63–377.99).ConclusionFoot and ankle characteristics were different in individuals with PFOA compared to control participants, however there was no difference in dynamic knee valgus during single leg squat. Clinical interventions to address greater foot mobility may be relevant for PFOA.

A cross-sectional observational study comparing foot and ankle characteristics in people with stroke and healthy controls

Purpose: The purpose of this study was to explore and compare foot and ankle characteristics in people with stroke and healthy controls; and between stroke fallers and non-fallers.Methods: Participants were recruited from community groups and completed standardized tests assessing sensation, foot posture, foot function, ankle dorsiflexion and first metatarsal phalangeal joint range of motion (1st MPJ ROM), hallux valgus presence and severity.Results: Twenty-three stroke participants (mean age 75.09 ± 7.57 years; 12 fallers) and 16 controls (mean age 73.44 ± 8.35 years) took part. Within the stroke group, reduced 1st MPJ sensation (p = 0.016) and 1st MPJ ROM (p = 0.025) were observed in the affected foot in comparison to the non-affected foot; no other differences were apparent. Pooled data (for both feet) was used to explore between stroke/control (n = 78 feet) and stroke faller/non-faller (n = 46 feet) group differences. In comparison to the control group, stroke participants exhibited reduced sensation of the 1st MPJ (p = 0.020), higher Foot Posture Index scores (indicating greater foot pronation, p = 0.008) and reduced foot function (p = 0.003). Stroke fallers exhibited significantly greater foot pronation in comparison to non-fallers (p = 0.027).Conclusions: Results indicated differences in foot and ankle characteristics post stroke in comparison to healthy controls. These changes may negatively impact functional ability and the ability to preserve balance. Further research is warranted to explore the influence of foot problems on balance ability and falls in people with stroke.Implications for RehabilitationFoot problems are common post stroke.As foot problems have been linked to increased fall risk among the general population we recommend that it would be beneficial to include foot and ankle assessments or a referral to a podiatrist for people with stroke who report foot problems.Further research is needed to explore if we can improve functional performance post stroke and reduce fall risk if treatment or prevention of foot problems can be included in stroke rehabilitation.

Foot and ankle characteristics associated with falls in adults with established rheumatoid arthritis: a cross-sectional study.

BackgroundPeople with rheumatoid arthritis (RA) have an increased risk of falls. The foot is a common site of pathology in RA and foot problems are reported in up to 90 % of patients with established disease. The aim of this study was to determine whether foot and ankle characteristics are associated with falls in people with RA.MethodsAdults with RA were recruited from rheumatology outpatient clinics in Auckland, New Zealand. Participants reported whether they had fallen in the preceding year, and the number of falls. Clinical characteristics, common fall risk factors, and foot and ankle variables were measured. Univariate parametric and non-parametric analysis compared fallers and non-fallers on all variables to determine significant differences. Logistic regression analysis identified variables independently associated with falls.ResultsTwo hundred and one participants were prospectively recruited. At least one fall in the preceding 12-months was reported by 119 (59 %) participants. Univariate analysis showed that fallers had significantly longer mean disease duration, more co-morbid conditions, an increase in lower limb tender joints, higher midfoot peak plantar pressures and were more likely to have a history of vascular disease than non-fallers. Fallers also reported greater difficulty with activities of daily living, increased fear of falling and greater self-reported foot impairment. Logistic regression analysis revealed that increased midfoot peak plantar pressures (odds ratio (OR) 1.12 [for each 20 kPa increase], 95 % confidence interval (CI) 1.00-1.25), self-reported foot impairment (OR 1.17 [for each three point increase], 95 % CI 1.05-1.31) and history of vascular disease (OR 3.22, 95 % CI 1.17-8.88) were independently associated with a fall in the preceding 12 months.ConclusionsElevated midfoot peak plantar pressures, self-reported foot impairment and vascular disease are associated with falls in people with RA. Assessment of foot deformity, foot function and self-reported foot impairment may be of benefit when considering falls prevention strategies in people with RA.Trial registrationAustralia New Zealand Clinical Trial Registry (trial ACTRN12612000597897).

The immediate effect of facilitation technique applied to the ankle joint on the balance ability in young healthy subjects

Background: The ankle joint stability is considered important component for the standing balance. Foot and ankle characteristics, such as ankle flexibility and strength, contribute to functional ability in elderly people. Therefore, improvement of the ankle joint stability is essential to obtain the better balance ability. Previously, a variety of approaches applied to the ankle joint to improve the standing balance have been investigated. However, the number of studies which explored the effect of the facilitation technique is few, although the techniques have been used in order to improve balance ability in the patients with neurological disorders. Purpose: The purpose of this study was to investigate the immediate effect of the facilitation technique applied to the ankle joint on the balance ability in young healthy subjects by comparing before and after the intervention. Methods:Nine young healthy subjects (fivemale and four female, 25.2± 1.0 ages, height 169.8± 7.8 cm, weight 59. 6± 7.1 kg) were recruited. The subjects who had orthopedic disease that could cause balance disability were excluded. A force platform (Gravicorder, Anima, Tokyo, Japan) was used to measure postural sway. The displacement of the center of pressure (COP) was measured at a 20Hz frequency. The subjects were asked to perform single leg stance with their right leg with their eyes open for 30 seconds and to look at a fixed eye-level target approximately 2m away before and after the intervention. The subjects were asked to sit on a chair, and keep their pelvis upright without leaning on the backrest during the intervention. A physiotherapist held and compressed the medial and lateral gastrocnemius muscle by their both hands and induces the plantarflexion with their forefoot on the floor 30 times. The total length of the body sway (LNG), the rectangle area (REC. area), the environmental area (ENV. area), the root mean square (RMS) and the root mean square area (RMS. area) were calculated as an indicator of the balance ability. A paired t-test was used for statistical analysis to compare the variables before and after interventions. The level of significance was set at p< 0.05. Results: There was a significant decrease of ENV.area, RMS and RMS.area (p< 005). However the values of LNG and REC. area did not show significant decrease. Conclusion(s): This result suggested the facilitation technique of the ankle joint could enable the participants to maintain one leg stance with smaller perturbation. The future research will be recommended to investigate the effect of this intervention on the balance ability in elderly people and patients with neurological disorders. Implications: The facilitation technique can be an effective approach for the improvement of the standing balance. This technique can be applied not only to elderly people but also the patients with neurological disorders who are not able to performvoluntarymovement of the ankle joint as voluntary movement of the joint is not required.

Association of foot and ankle characteristics with progression of venous disease.

Although risk factors have been identified for the cross-sectional prevalence of venous disease, few studies have investigated risk factors for venous disease progression. Therefore, the aim of this study was to investigate the relationship between foot and ankle characteristics and the progression of venous disease. A total of 1025 participants from the San Diego Population Study were assessed at baseline and at follow-up 11 years later. Risk factors were assessed by questionnaire and physical measurements, while venous disease was determined by physical examination and Duplex ultrasound. Change in venous disease from baseline to 11-year follow-up was characterized as stable or progression. Those with venous disease progression were less likely to spend increased time lying per day, more likely to have a history of hypertension, lie supine for a surgical procedure greater than an hour, and report an occupation that was professional, technical, administrative, or management. Those with a normal arch reported the greatest degree of plantar flexion. In multivariable logistic regression, including adjustment for weight-bearing arch characteristics, greater dorsiflexion (per 5 degrees) was significantly associated with progression of venous disease (OR = 1.11, p = 0.01). A weight-bearing flat arch compared to a weight-bearing normal arch was of borderline significance as a protective factor against progression of venous disease with adjustment for dorsiflexion (OR = 0.56, p = 0.07). Our results indicate that the ability to have higher levels of dorsiflexion is a risk factor for the progression of venous disease, and suggest a role for connective tissue laxity in the pathogenesis of venous disease.

Kinematic foot types in youth with equinovarus secondary to hemiplegia

BackgroundElevated kinematic variability of the foot and ankle segments exists during gait among individuals with equinovarus secondary to hemiplegic cerebral palsy (CP). Clinicians have previously addressed such variability by developing classification schemes to identify subgroups of individuals based on their kinematics. ObjectiveTo identify kinematic subgroups among youth with equinovarus secondary to CP using 3-dimensional multi-segment foot and ankle kinematics during locomotion as inputs for principal component analysis (PCA), and K-means cluster analysis. MethodsIn a single assessment session, multi-segment foot and ankle kinematics using the Milwaukee Foot Model (MFM) were collected in 24 children/adolescents with equinovarus and 20 typically developing children/adolescents. ResultsPCA was used as a data reduction technique on 40 variables. K-means cluster analysis was performed on the first six principal components (PCs) which accounted for 92% of the variance of the dataset. The PCs described the location and plane of involvement in the foot and ankle. Five distinct kinematic subgroups were identified using K-means clustering. Participants with equinovarus presented with variable involvement ranging from primary hindfoot or forefoot deviations to deformtiy that included both segments in multiple planes. ConclusionThis study provides further evidence of the variability in foot characteristics associated with equinovarus secondary to hemiplegic CP. These findings would not have been detected using a single segment foot model. The identification of multiple kinematic subgroups with unique foot and ankle characteristics has the potential to improve treatment since similar patients within a subgroup are likely to benefit from the same intervention(s).

The association between physical characteristics of the ankle joint and the mobility performance in elderly people with type 2 diabetes mellitus

Previous studies showed that older adults with diabetes have a worse mobility performance as compared with those without diabetes. Studies also demonstrated that older adults with diabetes have weakened ankle muscle strength, reduced joint range in ankle dorsiflexion and worsened ankle joint proprioception as compared with control population. The purpose of the present study was to examine the relationship between the physical characteristics of the ankle joint and the mobility performance in older adults with type 2 diabetes. Older adults with type 2 diabetes (n=85) were recruited, and Timed Up and Go test (TUG) for mobility assessment was performed. Active ankle joint repositioning test was used for assessing the ankle joint proprioception sense; peak torque of ankle dorsiflexors and plantar flexors were tested by using a Cybex Norm dynamometer, and weight-bearing lunge test (WBLT) was used for assessing the stiffness of ankle dorsiflexion. Our results showed that age, body mass index (BMI), normalized peak torque of plantar flexors and dorsiflexors, active ankle joint repositioning test errors and the WBLT distance were significantly correlated with the TUG (all p<0.001). These ankle characteristics, together with the demographic data of the subjects, contributed 59.9% of the variance in the TUG by multiple regression analysis. Body mass, ankle plantar flexors strength and ankle joint proprioception are important factors contributing to the physical mobility of the older adults with type 2 diabetes.

Quantitative analysis of human ankle characteristics at different gait phases and speeds for utilizing in ankle-foot prosthetic design

BackgroundAnkle characteristics vary in terms of gait phase and speed change. This study aimed to quantify the components of ankle characteristics, including quasi-stiffness and work in different gait phases and at various speeds.MethodsThe kinetic and kinematic data of 20 healthy participants were collected during normal gait at four speeds. Stance moment-angle curves were divided into three sub-phases including controlled plantarflexion, controlled dorsiflexion and powered plantarflexion. The slope of the moment-angle curves was quantified as quasi-stiffness. The area under the curves was defined as work.ResultsThe lowest quasi-stiffness was observed in the controlled plantarflexion. The fitted line to moment-angle curves showed R2 > 0.8 at controlled dorsiflexion and powered plantarflexion. Quasi-stiffness was significantly different at different speeds (P = 0.00). In the controlled dorsiflexion, the ankle absorbed energy; by comparison, energy was generated in the powered plantarflexion. A negative work value was recorded at slower speeds and a positive value was observed at faster speeds. Ankle peak powers were increased with walking speed (P = 0.00).ConclusionsOur findings suggested that the quasi-stiffness and work of the ankle joint can be regulated at different phases and speeds. These findings may be clinically applicable in the design and development of ankle prosthetic devices that can naturally replicate human walking at various gait speeds.

The relationship between ankle joint physiological characteristics and balance control during unilateral stance

BackgroundThe role that the ankle's physiological characteristics play in maintaining balance during quiet stance has been well documented. However, the role of the ankle in maintaining balance during more challenging conditions is questionable. As such, the objectives of this study were to identify any significant relationships between the physiological characteristics of the ankle joint and the ability to maintain more challenging unilateral stance. Participants21 healthy, adult athletes (age=24.67±5.42 years; height=175.34±7.48cms; weight=79.09±14.07kg). ProceduresPassive resistance and joint position sense in the sagittal plane of the ankle, and active dorsiflexion range of motion of each subject was assessed, in addition to centre of pressure parameters during 20s unilateral stance. ResultsPearson's product moment correlation coefficient found significant positive correlations between Dpeaktorque and sway area (r=.554); Ax range (r=.449); and Ay range (r=.471). Significant negative correlations were found between Ppeaktorque angle and sway area (r=−.538, p=.012), Ax range (r=−.590, p=.005) and Ay range (r=−.439, p=.046). DiscussionThe results highlighted limited relationships between unilateral stance balance control and the ankle characteristics commonly associated with quiet stance balance control and has, thus, further questioned the role that the ankle plays during more challenging stance conditions. The majority of balance training protocols in the athletic community focuses on the distal joints, however, this needs re-addressing in order to maximise performance.