Peak Ankle Plantarflexion Moment Research Articles

Comparing Sagittal-Plane Biomechanics of Drop Jump Landing in Athletes With and Without Knee Osteoarthritis 2-Year Post-Anterior Cruciate Ligament Reconstruction.

The study aimed to determine differences in sagittal-plane joint biomechanics between athletes with and without knee osteoarthritis (OA) during drop vertical jump 2years after anterior cruciate ligament reconstruction (ACLR). Forty-one athletes with ACLR completed motion analysis testing during drop vertical jump from 30cm. Sagittal-plane peak joint angles and moments and joint contributions to total support moment (TSM) were calculated during first landing. Medial compartment knee OA of the reconstructed knee was evaluated using Kellgren-Lawrencescores (ACLR group: Kellgren-Lawrence <2; ACLR-OA group: Kellgren-Lawrence ≥2). The ACLR-OA group (n = 13) had higher hip and lower knee contributions in the surgical limb than the ACLR group and their nonsurgical limb. Further, the ACLR-OA group had higher peak hip extension moment than the ACLR group (P = .024). The ACLR-OA group had significantly lower peak knee extension and ankle plantar flexion moments and TSM (P ≤ .032) than ACLR group. The ACLR-OA group landed with increased hip extension moment, decreased knee extension and ankle plantar flexion moments and TSM, and decreased knee and increased hip contributions to TSM compared with ACLR group. The ACLR-OA group may have adopted movement patterns to decrease knee load and compensated by shifting the load to the hip. Clinicians may incorporate tailored rehabilitation programs that mitigate the decreased knee load to minimize the risk of knee OA after ACLR.

The effect of immediate neuromuscular training on ankle biomechanics in individuals with functional ankle instability

Functional ankle instability arises from recurrent ankle sprains. Neuromuscular training is employed to enhance ankle stability in individuals who experience functional ankle instability. The study involved 24 male university students with functional ankle instability, undergoing ankle neuromuscular training on three surfaces. The OpenSim musculoskeletal model assessed effects on ankle kinematics, kinetics, and muscle activity. Using one-way repeated measures ANOVA and one-dimensional statistical non-parametric mapping to distinguish differences among training surfaces. The study aimed to compare biomechanical characteristics of ankle motion in individuals with functional ankle instability undergoing immediate neuromuscular training on a foam cushion surface versus training on level-ground and artificial turf. Results showed foam cushion training significantly increased tibialis anterior and gastrocnemius medial activation during walking (p &lt; 0.05), with no differences observed in peak ankle plantarflexion, peroneus longus, and gastrocnemius lateral. Foam cushion training further increased activation in four muscles and peak ankle plantarflexion moment during jogging and fast running (p &lt; 0.05). Furthermore, foam cushion training reduced subtalar mobility (p &lt; 0.05) and showed greater dorsiflexion angles during jogging and fast running (p &lt; 0.05). Therefore, immediate ankle neuromuscular training on a foam cushion is more advantageous in enhancing ankle stability among individuals with functional ankle instability, positively impacting functional ankle instability improvement.

The effect of immediate neuromuscular training on ankle biomechanics in individuals with functional ankle instability

Functional ankle instability arises from recurrent ankle sprains. Neuromuscular training is employed to enhance ankle stability in individuals who experience functional ankle instability. The study involved 24 male university students with functional ankle instability, undergoing ankle neuromuscular training on three surfaces. The OpenSim musculoskeletal model assessed effects on ankle kinematics, kinetics, and muscle activity. Using one-way repeated measures ANOVA and one-dimensional statistical non-parametric mapping to distinguish differences among training surfaces. The study aimed to compare biomechanical characteristics of ankle motion in individuals with functional ankle instability undergoing immediate neuromuscular training on a foam cushion surface versus training on level-ground and artificial turf. Results showed foam cushion training significantly increased tibialis anterior and gastrocnemius medial activation during walking (p &lt; 0.05), with no differences observed in peak ankle plantarflexion, peroneus longus, and gastrocnemius lateral. Foam cushion training further increased activation in four muscles and peak ankle plantarflexion moment during jogging and fast running (p &lt; 0.05). Furthermore, foam cushion training reduced subtalar mobility (p &lt; 0.05) and showed greater dorsiflexion angles during jogging and fast running (p &lt; 0.05). Therefore, immediate ankle neuromuscular training on a foam cushion is more advantageous in enhancing ankle stability among individuals with functional ankle instability, positively impacting functional ankle instability improvement.

Lower Limb Joint Mechanics during Maximal Accelerative and Decelerative Running.

Maximal acceleration and deceleration tasks are frequently required in team sports, often occurring rapidly in response to external stimuli. Accelerating and decelerating can be associated with lower limb injuries, thus knowledge of joint mechanics during these tasks can improve the understanding of both human high performance and injury mechanisms. The current study investigated the fundamental differences in lower limb joint mechanics when accelerating and decelerating by directly comparing the hip, knee and ankle joint moments and work done between the two tasks. Twenty participants performed maximal effort acceleration and deceleration trials, with three-dimensional marker trajectories and ground reaction forces collected simultaneously. Experimental data was combined with inverse dynamics analysis to compute joint moments and work. Net joint work for all lower limb joints was positive during acceleration, and negative during deceleration. This occurred due to significantly greater positive work production from the ankle and hip during acceleration, and significantly greater negative work production from all joints during deceleration. The largest contributions to positive work during acceleration came from the ankle, followed by the hip and knee joints; whilst the largest contributions to negative work during deceleration came from the knee and hip joints, followed by the ankle. Peak joint moments were significantly greater when decelerating compared to accelerating, except for the peak ankle plantarflexion and hip flexion moments which were significantly greater when accelerating. Our findings may help to guide training interventions which aim to enhance the performance of acceleration and deceleration tasks, whilst also mitigating the associated injury risk.

First tarsometatarsal joint mobility in hallux valgus during gait: A synchronized ultrasound and three-dimensional motion capture analysis

PurposeTo quantify the vertical translation between the first metatarsal and medial cuneiform during the stance phase of gait in young individuals with and without hallux valgus.DesignThis cross-sectional observational study included 34 young adults (male, n = 4; female, n = 30) who were divided into three groups according to the hallux valgus angle: control (< 20°, n = 13), mild hallux valgus (≥ 20° to < 30°, n = 12), and moderate hallux valgus (≥ 30°, n = 9). The mobility of the first tarsometatarsal joint was evaluated during the stance phase using B-mode ultrasound synchronized with a motion analysis system.ResultsThe medial cuneiform shifted more plantar during the early phase in mild hallux valgus and during the middle and terminal phases in moderate hallux valgus than in control. The severity of the hallux valgus was correlated with a trend toward plantar shift of the medial cuneiform. The first metatarsal was located more dorsal than the medial cuneiform; however, there was no significant variation. No significant differences in the peak ankle plantarflexion angle and moment were noted between the groups.ConclusionThe hypermobility of the first tarsometatarsal joint, especially plantar displacement of the medial cuneiform in the sagittal plane, was found in young individuals with hallux valgus during the stance phase of gait, and the mobility increased with the severity of hallux valgus. Our findings suggest the significance of preventing hallux valgus deformity early in life.

Females with hip-related pain demonstrate reduced kinetics at the hip and ankle during terminal stance of gait

BackgroundIndividuals with hip-related pain (HRP) commonly report pain with walking and demonstrate altered movement patterns compared to healthy controls (HCs). Individuals with HRP may attempt to reduce pain during walking by decreasing kinetics and joint forces at the hip through increased use of the ankle during pushoff. Research questionDo individuals with HRP have increased kinetics at the ankle and decreased kinetics at the hip during pushoff in gait compared to HCs, and do kinetic patterns differ between males and females with HRP? MethodsThis retrospective observational study included 42 individuals with HRP and 20 HCs. Participants completed overground gait trials at their self-selected speed while kinematics and kinetics were recorded through a motion capture system and force plates. Peak internal hip and ankle moments and hip flexion and ankle plantarflexion angular impulse during terminal stance were used in general estimating equations for comparison of group by limb interactions for males and females separately, as well as a comparison of males and females within the HRP group. ResultsFemales with HRP demonstrated reduced hip flexion impulse on their involved limb (.070 Nm*s/kg*m) compared to female HCs (.083Nm*s/kg*m; p = .032), as well as reduced peak ankle plantarflexion moment (−.94Nm/kg*m) compared to their contralateral limb (−.99Nm/kg*m) and the involved limb of HRP males (−1.00Nm/kg*m) (p ≤ .007). There were no between-limb or between-group differences in hip or ankle peak moments or impulses in males. SignificanceFemales with HRP show decreased kinetics at both the hip and ankle; these patterns were not identified in males. Future investigations should examine whether increasing ankle kinetics during pushoff reduces pain at the hip, as this may be a valuable clinical treatment strategy.

Sex difference in effect of ankle landing biomechanics in sagittal plane on knee valgus moment during single-leg landing

Ankle landing strategies affects the biomechanical characteristics of the knee joint, especially knee frontal plane loading. However, no studies have investigated whether the association between ankle landing biomechanics in sagittal plane and the knee frontal plane loading differs between sexes. The purpose of this study was to examine whether there is a sex difference in the effect of ankle plantar flexion at the contact angle, ankle range of motion (ROM), and ankle plantar flexion moment on knee valgus loading during single-leg landing. Twenty-five females and twenty-four males performed a single-leg landing. Joint kinematics and kinetics of the lower extremities were measured. The relationship between ankle biomechanics in the sagittal plane (ankle plantar flexion angle at contact, ROM, and peak ankle plantar flexion moment) and peak knee valgus moment were analyzed. In males, the larger ankle plantarflexion angle at contact and ROM were significantly associated with lower peak knee valgus moment. In addition, in males only, a greater peak ankle plantar flexion moment was significantly associated with a lower peak knee valgus moment and greater peak ankle inversion moment. Altering ankle landing strategies in the sagittal plane during single-leg landing may reduce the knee valgus moment, which is one of risk factors for anterior cruciate ligament injury, in males only.

Conclusion or Illusion: Quantifying Uncertainty in Inverse Analyses From Marker-Based Motion Capture due to Errors in Marker Registration and Model Scaling.

Estimating kinematics from optical motion capture with skin-mounted markers, referred to as an inverse kinematic (IK) calculation, is the most common experimental technique in human motion analysis. Kinematics are often used to diagnose movement disorders and plan treatment strategies. In many such applications, small differences in joint angles can be clinically significant. Kinematics are also used to estimate joint powers, muscle forces, and other quantities of interest that cannot typically be measured directly. Thus, the accuracy and reproducibility of IK calculations are critical. In this work, we isolate and quantify the uncertainty in joint angles, moments, and powers due to two sources of error during IK analyses: errors in the placement of markers on the model (marker registration) and errors in the dimensions of the model’s body segments (model scaling). We demonstrate that IK solutions are best presented as a distribution of equally probable trajectories when these sources of modeling uncertainty are considered. Notably, a substantial amount of uncertainty exists in the computed kinematics and kinetics even if low marker tracking errors are achieved. For example, considering only 2 cm of marker registration uncertainty, peak ankle plantarflexion angle varied by 15.9°, peak ankle plantarflexion moment varied by 26.6 N⋅m, and peak ankle power at push off varied by 75.9 W during healthy gait. This uncertainty can directly impact the classification of patient movements and the evaluation of training or device effectiveness, such as calculations of push-off power. We provide scripts in OpenSim so that others can reproduce our results and quantify the effect of modeling uncertainty in their own studies.

Energy dissipation during single-leg landing from three heights in individuals with and without chronic ankle instability

ABSTRACT Inadequate energy dissipation during landing may increase the risk of ankle sprain. Mechanical demands (landing height) in landing tasks may affect the biomechanical differences between individuals with and without chronic ankle instability (CAI). However, energy dissipation strategies during landing from various heights in individuals with CAI are unclear. The purpose of this study was to compare the effect of landing height on lower extremity biomechanics between individuals with and without CAI. Eleven participants in each of the CAI and Control group performed a single-leg landing from three heights (30, 40, and 50 cm). We calculated the contribution of each joint to total energy dissipation at 50-ms intervals during 0–200 ms post-initial contact (IC). Peak joint angles and moments and joint stiffnesses were calculated during 0–200 ms post-IC. Two-way mixed analysis of variance revealed significant group-by-height interactions for hip energy dissipation at 101–150 ms post-IC and peak ankle plantarflexion and hip extension moment. These significant interactions suggested that the effects of landing height on the ankle and hip joints differ between individuals with and without CAI. The effect of mechanical demands on altered landing biomechanics among CAI populations should be considered in biomechanical studies and clinical practice.

Neuromechanics of Middle-Distance Running Fatigue: A Key Role of the Plantarflexors?

This study aimed to investigate the changes in lower limb kinematics, kinetics, and muscle activation during a high-intensity run to fatigue (HIRF). Eighteen male and female competitive middle-distance runners performed a HIRF on an instrumented treadmill at a constant but unsustainable middle-distance speed (~3 min) based on a preceding maximum oxygen uptake (V˙O2max) test. Three-dimensional kinematics and kinetics were collected and compared between the start, 33%, 67%, and the end of the HIRF. In addition, the activation of eight lower limb muscles of each leg was measured with surface EMG (sEMG). Time to exhaustion was 181 ± 42 s. By the end of the HIRF (i.e., vs the start), ground contact time increased (+4.0%), whereas flight time (-3.2%), peak vertical ground reaction force (-6.1%), and vertical impulse (-4.1%) decreased (all P < 0.05), and joint angles at initial contact became more (dorsi)flexed (ankle, +1.9°; knee, +2.1°; hip, +3.6°; all P < 0.05). During stance, by the end of the HIRF: peak ankle plantarflexion moment decreased by 0.4 N·m·kg-1 (-9.0%), whereas peak knee extension moment increased by 0.24 N·m·kg-1 (+10.3%); similarly, positive ankle plantarflexion work decreased by 0.19 J·kg-1 (-13.9%), whereas positive knee extension work increased by 0.09 J·kg-1 (+33.3%; both P < 0.05) with no change in positive hip extension work. Hip extensor surface EMG amplitude increased during the late swing phase (+20.9-37.3%; P < 0.05). Running at a constant middle-distance pace led primarily to the fatigue of the plantarflexors with a compensatory increase in positive work done at the knee. Improving the fatigue resistance of the plantarflexors might be beneficial for middle-distance running performance.

Movement compensations during a step ascent task are associated with stair climbing performance in people with multiple sclerosis.

The biomechanical mechanisms underlying stair climbing limitations are poorly understood in people with multiple sclerosis (MS). Are trunk and pelvis motion and lower extremity joint moments during step ascent different between MS and control groups? Are step ascent biomechanics and stair climbing performance associated in people with MS? 20 people with MS (49 ± 12 years, EDSS range: 1.5-5.5) and ten control participants (48 ± 12 years) underwent three-dimensional motion analysis while ascending a 15.2-cm step and also completed a timed Functional Stair Test. Main effects of group (MS vs Control) and limb (Stronger/Dominant vs Weaker/Non-dominant) and interactions were assessed using two-way analyses of variance. Associations between movement patterns during the step ascent and Functional Stair Test performance were performed using Pearson's correlations and backward stepwise linear regression. Significant group main effects were observed in greater sagittal pelvis excursion (p < 0.001), greater sagittal (p = 0.013) and frontal (p = 0.001) trunk excursion, and lower trail limb peak ankle plantar flexion moment (p < 0.001) of the MS group. Significant limb main effects were observed with greater sagittal trunk excursion (p = 0.037) and peak trail limb ankle plantar flexion moment (p = 0.037) in the stronger/dominant limb. A significant interaction was observed in peak knee extensor moment (p = .002). Stair climbing performance in the MS group correlated with sagittal (r = .607, p=<0.001) and frontal pelvis excursions (r = 0.385, p = 0.014), sagittal trunk excursion (r = .411, p = 0.008), and ankle plantar flexion moments (r=-0.415, p = 0.008). Sagittal and frontal pelvis excursion and bilateral handrail use explained a significant amount of variability in stair climbing performance (Adj R2 = 0.775). In conclusion, despite the presence of proximal and distal lower extremity movement pattern compensations during a step ascent task, larger pelvis angular excursions are associated with impaired stair climbing performance in people with MS and may serve as targets for future rehabilitation interventions.

Effects of dual tasks on kinematic and kinetic performances during stair descent: respective effects of manual and cognitive tasks.

Stair descent is one of the most common and challenging daily activities for several populations, particularly under dual-task conditions. This study investigated the effects of cognitive or manual task on kinematics and kinetics during stair descent. A total of 37 participants performed stair descent under three conditions: stair descending only, stair descending while performing a cognitive task and stair descending while performing a manual task. Kinematic and kinetic data were collected. Multivariate analysis of variance with repeated measures was conducted to test the significant differences among the three conditions. The gait performance, loading rate, lower limb joint moments and powers were significantly lower under the two dual-task conditions compared with stair descending only. The participants had lower knee flexion/extension range of motion, loading rate, peak hip flexion moment, first peak knee extensor moment, second peak ankle plantar flexion moment, first knee power absorption and less stride width under the manual task compared with the cognitive task. Dual tasks during stair descent had a significant impact on the kinematics and kinetics of motion, and the effect was more significant while performing a concurrent manual task in healthy young adults. Further studies could focus on the complexity level of dual tasks on the biomechanical parameters during stair walking.

Progression of Fatigue Modifies Primary Contributors to Ground Reaction Forces During Drop Landing.

Few studies have focused on the effect of fatigue severity on landing strategy. This study aimed to investigate the effect of fatigue progression on ground reaction force during landing. Eighteen participants performed a fatigue exercise protocol. Then participants performed drop landings at three levels of fatigue: no fatigue, medium fatigue, and severe fatigue. Multiple linear regression was conducted to identify the predictors of the peak vertical ground reaction force at each level of fatigue. Two-way ANOVAs were conducted to test the effect of fatigue on the vertical ground reaction force and the predictors. For the vertical ground reaction force, the knee joint stiffness and the knee angle at initial contact were the main predictors at no fatigue. The peak knee flexion angle and knee power were the main predictors at medium fatigue. However, the peak ankle plantarflexion moments became the main predictor at severe fatigue. The vertical ground reaction force decreased from no to medium fatigue (p = 0.001), and then increased from medium to severe fatigue (p = 0.034). The knee joint stiffness decreased from no to medium fatigue (p = 0.049), and then remained unchanged from medium to severe fatigue. The peak knee flexion angle increased from no to medium fatigue (p = 0.001), and then slightly decreased from medium to severe fatigue (p = 0.051). The results indicate that fatigue progression causes a transition from stiff to soft landing, and then to stiff landing. Participants used ankle joints more to control the landing intensity at severe fatigue.

Knee joint biomechanics of patients with unilateral total knee arthroplasty during stationary cycling

Stationary cycling is typically recommended following total knee arthroplasty (TKA) operations. However, knee joint biomechanics during cycling remains mostly unknown for TKA patients. Biomechanical differences between the replaced and non-replaced limb may inform applications of cycling in TKA rehabilitation. The purpose of this study was to examine the knee joint biomechanics of TKA patients during stationary cycling. Fifteen TKA participants cycled at 80 revolutions per minute and workrates of 80 W and 100 W while kinematics (240 Hz) and pedal reaction forces using a pair of instrumented pedals (1200 Hz) were collected. A 2x2 (limb × workrate) repeated measures ANOVA was run with an alpha of 0.05. Peak knee extension moment (KEM, p = 0.034) and vertical pedal reaction force (p = 0.038) were significantly reduced in the replaced limbs compared to non-replaced limbs by 21.3% and 5.3%, respectively. Peak KEM did not change for TKA patients with the increased workrate (p = 0.750). However, both peak hip extension moment (p = 0.009) and ankle plantarflexion moment (p = 0.017) increased due to increased workrate. Patients following TKA showed similar decreases in peak KEM and vertical pedal reaction force in their replaced compared to non-replaced limbs, as previously seen in gait. Patients of TKA may rely on their hip and ankle extensors to increases in workrate. Increasing intensity by 20 W did not exacerbate any inter-limb differences for peak KEM and vertical PRF.

Joint moments and power in the acceleration phase of bend sprinting

Joint kinetics of the lower limb (hip, knee, ankle, midfoot and metatarsophalangeal joints) were investigated during the acceleration phase of bend sprinting and straight-line sprinting. Within the bend sprinting literature, it is generally accepted that sprint performance on the bend is restricted by moments in the non-sagittal plane preventing the production of force in the sagittal plane. However, there is limited evidence in conditions representative of elite athletics performance that supports this hypothesis. Three-dimensional kinematic and ground reaction force data were collected from seven participants during sprinting on the bend (36.5 m radius) and straight, allowing calculation of joint moment, power and energy. No changes in extensor moment were observed at the hip and knee joints. Large effect sizes (g = 1.07) suggest a trend towards an increase in left step peak ankle plantarflexion moment. This could be due to a greater need for stabilisation of the ankle joint as a consequence of non-sagittal plane adaptations of the lower limb. In addition, the observed increase in peak MTP joint plantar-flexor moment might have implications for injury risk of the fifth metatarsal. Energy generation, indicated by positive power, in the sagittal plane at the MTP and ankle joints was moderately lower on the bend than straight, whilst increases in non-sagittal plane energy absorption were observed at the ankle joint. Therefore, energy absorption at the foot and ankle may be a key consideration in improving bend sprinting performance.

Unloading Shoes for Intermittent Claudication: A Randomised Crossover Trial

Introduction - Intermittent claudication is a common condition often managed with high-risk invasive arterial revascularisation procedures. The primary first-line non-invasive intervention of supervised exercise training is rarely available for several reasons. As such non-invasive management is often sub-optimal. This study aims to assess the functional effects and acceptability of rocker-soled shoes that were designed to relatively “unload” the calf muscles during walking in people with calf claudication due to peripheral arterial disease. Methods - In this randomised AB/BA crossover trial, participants completed two assessment visits up to two weeks apart. At each visit, participants completed walking tests whilst wearing the unloading shoes or visually-similar control shoes. At the end of the second visit, participants were given either the unloading or control shoes to use in their home environment for 2 weeks, with the instruction to wear them at least 4 hours every day. The primary outcome was total distance walked during a forced-pace, 6-minute walking test. We also assessed pain-free walking distance and gait biomechanical variables during usual-pace walking, adverse events, and participants’ opinions about the shoes. Data for continuous outcomes are presented as mean difference between conditions with corresponding 95% confidence interval Results - Thirty-four participants (27 males, mean age 68 years, mean ankle-brachial index 0.54) completed both assessment visits. On average, the 6-minute walk distance was 11 m greater when participants wore the control shoes (95% CI -5 to 26), whereas mean pain-free walking distance was 7 m greater in the unloading shoes (95% CI -17 to 32). Neither of these differences were statistically significant (p=0.18 and p=0.55, respectively). This was despite the unloading shoes reducing peak ankle plantar flexion moment (mean difference 0.2 Nm/kg, 95% CI 0.0 to 0.3) and peak ankle power generation (mean difference 0.6 W/kg, 95% CI 0.2 to 1.0) during pain-free walking. The survey and interview data was mixed, with no clear differences between the unloading and control shoes. Conclusion - Shoes with modified soles to relatively unload the calf muscles during walking conferred no substantial acute functional benefit over control shoes.

The effects of intensive dietary weight loss and exercise on gait in overweight and obese adults with knee osteoarthritis. The Intensive Diet and Exercise for Arthritis (IDEA) trial

The Intensive Diet and Exercise for Arthritis (IDEA) trial was an 18-month randomized controlled trial that enrolled 454 overweight and obese older adults with symptomatic and radiographic knee osteoarthritis (OA). Participants were randomized to either exercise (E), intensive diet-induced weight loss (D), or intensive diet-induced weight loss plus exercise (D + E) interventions. We previously reported that the clinical benefits of D + E were significantly greater than with either intervention alone (e.g., greater pain reduction, and better function, mobility, and health-related quality of life). We now test the hypothesis that D + E has greater overall benefit on gait mechanics compared to either intervention alone. Knee joint loading was analyzed using inverse dynamics and musculoskeletal modeling. Analysis of covariance determined the interventions’ effects on gait. The D + E group walked significantly faster at 18-month follow-up (1.35 m s−1) than E (1.29 m s−1, p = 0.0004) and D (1.31 m s−1, p = 0.0007). Tibiofemoral compressive impulse was significantly lower (p = 0.0007) in D (1069 N s) and D + E (1054 N s) compared to E (1130 N s). D had significantly lower peak hip external rotation moment (p = 0.01), hip abduction moment (p = 0.0003), and peak hip power production (p = 0.016) compared with E. Peak ankle plantar flexion moment was significantly less (p < 0.0001) in the two diet groups compared with E. There also was a significant dose-response to weight loss; participants that lost >10% of baseline body weight had significantly (p = 0.0001) lower resultant knee forces and lower muscle (quadriceps, hamstring, and gastrocnemius) forces than participants that had less weight loss. Compared to E, D produces significant load reductions at the hip, knee, and ankle; combining D with E attenuates these reductions, but most remain significantly better than with E alone.

The effects of compression stockings on the energetics and biomechanics during walking.

The purpose of this study was to explore how compression stockings affect the energetics and biomechanics during walking. Sixteen male adults participated in this study. Participants completed walking trials on the treadmill and force plates, wearing compression stockings (CS) or nothing as a control condition (CON). The data obtained included metabolic rate, muscle activation, step frequency and step length as well as their variability, joint kinematics and joint kinetics. The effect of compression stockings on metabolic rate was trivial (CS: 3.81 ± 0.44Wkg-1, CON: 3.83 ± 0.46Wkg-1, p = 0.84, d = 0.05). Activation of calf muscles, step frequency and step length as well as their variability, joint range of motion and joint powers did not show a significant difference between conditions (p = 0.09-0.90, d = 0.01-0.34). The peak knee extension moment during the early stance phase had a tendency to increase (CS: 0.57 ± 0.27Nmkg-1, CON: 0.51 ± 0.28Nmkg-1, p = 0.05, d = 0.19) while the peak knee flexion moment during the late swing phase had a tendency to decrease (CS: 0.16 ± 0.10Nmkg-1, CON: 0.19 ± 0.12Nmkg-1, p = 0.10, d = 0.21). The peak ankle dorsiflexion moment during the early stance phase significantly increased (CS: 0.11 ± 0.06Nmkg-1, CON: 0.08 ± 0.05Nmkg-1, p = 0.02, d = 0.58) while the peak ankle plantar flexion moment during the late swing phase significantly decreased (CS: 1.41 ± 0.12Nmkg-1, CON: 1.47 ± 0.14Nmkg-1, p = 0.02, d = 0.45). Compression stockings have a limited effect on improving energetics of walking, but they may play a role in improving biomechanics by altering the relative contribution of knee and ankle moments to propulsion.

Lower extremity characteristics in recurrent clubfoot: Clinical and gait analysis findings that may influence decisions for additional surgery

BackgroundPatients with recurrent clubfoot may seek intervention to address impairments that impact gait function. An understanding of these impairments and associated gait issues will provide valuable information about ongoing treatment requirements. Research QuestionThe purpose of this study was to describe the prevalence of impairments and associated gait deviations in children with recurrent clubfoot and to evaluate whether these findings differ depending on unilateral or bilateral presentation. MethodsEighty-four affected feet (42 unilateral, 21 bilateral) were retrospectively reviewed. History, clinical exam, and gait data were collected. Statistical analysis included evaluations of associations between clinical exam and gait parameters and differences among patients with unilateral versus bilateral clubfoot and a database of healthy controls. ResultsThe average age was 7.5 ± 3.3 years for unilateral and 7.0 ± 2.8 years for bilateral patients. Patients presented with limited passive ankle dorsiflexion (unilateral/bilateral:67%/57%), limited ankle plantar flexion strength (unilateral/bilateral:53%/55%), metatarsus adductus (unilateral/bilateral:86%/83%) and internal foot-thigh angles (unilateral/bilateral:83%/82%), while only a subset presented with internal bi-malleolar axis angles (unilateral/bilateral:36%/45%). The most common gait deviations were internal foot progression (unilateral/bilateral:76%/73%), external hip rotation (unilateral/bilateral:66%/69%), reduced peak ankle plantar flexion moments (unilateral/bilateral:84%/83%), and reduced peak ankle power generation (unilateral/bilateral:67%/74%). Passive dorsiflexion was significantly correlated with peak dorsiflexion during stance and swing in both groups. Patients with unilateral compared to bilateral clubfoot showed decreased peak dorsiflexion and an associated knee flexor moment. SignificancePatients with recurrent clubfoot show gait deviations at the ankle that can be explained by joint level impairment and compensations at the knee, hip and pelvis. Patients with unilateral clubfoot typically show decreased dorsiflexion range of motion and associated greater gait impacts and compensations than bilateral clubfoot. Understanding the relationships between impairments and gait function and the implications of unilateral versus bilateral clubfoot will help improve prognostic ability and optimize future treatment outcomes.

Amputee Locomotion: Joint Moment Adaptations to Running Speed Using Running-Specific Prostheses after Unilateral Transtibial Amputation.

The objective of this study was to investigate three-dimensional lower extremity joint moment differences between limbs and speed influences on these differences in individuals with lower extremity amputations using running-specific prostheses. Eight individuals with unilateral transtibial amputations and 8 control subjects with no amputations ran overground at three constant velocities (2.5, 3.0, and 3.5 m/sec). A 2 × 2 × 3 (group × leg × speed) repeated-measures analysis of variance with Bonferroni adjustments determined statistical significance. The prosthetic limb generated significantly greater peak ankle plantarflexion moments and smaller peak ankle varus, knee stance extension, knee swing flexion, knee internal rotation, hip stance flexion, hip swing flexion, hip swing extension, hip valgus, and hip external rotation moments than the intact limb did. The intact limb had greater peak hip external rotation moments than control limbs did, but all other peak moments were similar between these limbs. Increases in peak hip stance and knee swing flexion moments associated with speed were greater in the intact limb than in the prosthetic limb. Individuals with amputation relied on the intact limb more than the prosthetic limb to run at a particular speed when wearing running-specific prostheses, but the intact joints were not overloaded relative to the control limbs.