Effect of Strength and Plyometric Training on Kinematics in Female Novice Runners.

ABSTRACT: Harrison, K, Williams, DSB III, Darter, BJ, Zernicke, RF, Shall, M, and Finucane, S. Effect of strength and plyometric training on kinematics in female novice runners. J Strength Cond Res 38(6): 1048-1055, 2024-Both running performance and injury have been associated with running kinematics. Plyometric training improves run performance and reduces injury risk in court-sport and field-sport athletes. The aim of this study was to assess longitudinal changes in kinematics in novice runners before and after a typical beginners' running program, compared with those who perform a plyometric intervention before running. Fifty-seven novice female runners were assigned to the control group (8 weeks walking +8 weeks running) or the intervention group (8 weeks strength or plyometric training +8 weeks running). Kinematics were assessed at baseline, 8 weeks, and 16 weeks. Joint angles throughout the stride of those who completed the training ( n = 21) were compared between groups and assessment time points using a statistical parametric mapping 2-way analysis of variance, with group and study time point as independent variables. There was no interaction effect of group and study time point ( p > 0.05), indicating that both training programs had similar effects on running kinematics. There was a main effect of time for sagittal plane knee and hip kinematics ( p < 0.001); after training, subjects ran with a more extended leg, particularly during swing. Programs of 8 weeks of preparatory training, followed by 8 weeks of running, resulted in altered sagittal plane biomechanics, which have previously been related to improved running economy. A greater volume of plyometric, run training or concurrent plyometric and run training may be required to elicit changes in running form associated with lower injury risk.

Perceptions of prosthetic attention among lower limb prosthesis users: a focus group study.

PURPOSE: Use of a lower limb prosthesis generally requires increased cognitive effort to compensate for missing motor and sensory inputs. This study sought to examine how lower limb prosthesis users perceive paying attention to their prosthesis(es) in daily life. MATERIALS AND METHODS: Focus groups with lower limb prosthesis users were conducted virtually using semi-structured questions. Verbatim transcripts were excerpted, coded, and reconciled. Inductive thematic analysis was undertaken to identify experiences shared by participants. RESULTS: Five themes emerged from five focus groups conducted with thirty individuals: Paying attention to my prosthesis is just what I have to do; I pay attention to how my prosthetic socket fits and feels every day; I pay attention because I don't want to fall; I pay attention because I have to learn to do things in a new way; and If I can trust that my prosthesis will do what I want, I can pay less attention to it. CONCLUSIONS: Prosthetic attention, including both background and foreground attention, is a shared experience among lower limb prosthesis users. The amount and frequency of prosthetic attention fluctuates throughout the day and changes over time. Measuring attention could inform the evaluation and prescription of technology intended to reduce cognitive effort.

Walking or performing mobility tasks with a prosthesis requires increased attention and may limit the cognitive resources available for other important activities.Lower limb prosthesis users report paying attention to their prosthesis(ses) to avoid falling, to maintain the fit of their prosthetic socket, and to learn to complete mobility tasks with a prosthesis.Clinicians should discuss prosthetic attention with new prosthesis users and explain how it is expected to decrease over time.Prosthetic technology may affect prosthetic attention but development of a measure to assess prosthetic attention is needed to accurately evaluate this relationship.

Changes in frontal plane kinematics over 12-months in individuals with the Percutaneous Osseointegrated Prosthesis (POP).

BACKGROUND: A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. OBJECTIVE: Examine changes in frontal plane movement patterns after BAP implantation. METHODS: Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12-months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. RESULTS: Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. CONCLUSIONS: Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while within-participant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.

The Running Readiness Scale as an Assessment of Kinematics Related to Knee Injury in Novice Female Runners.

CONTEXT: Frontal- and transverse-plane kinematics have been prospectively identified as risk factors for running-related injuries in females. The Running Readiness Scale (RRS) may allow for clinical evaluation of these kinematics. OBJECTIVES: To determine the reliability and validity of the RRS as an assessment of frontal- and transverse-plane running kinematics. DESIGN: Cross-sectional study. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 56 novice female runners (median [interquartile range] age = 34 years [26-47 years]). MAIN OUTCOME MEASURE(S): We collected 3-dimensional kinematics during running and RRS tasks: hopping, plank, step-ups, single-legged squats, and wall sit. Five clinicians assessed RRS performances 3 times each. Interrater and intrarater reliabilities of the total RRS score and individual tasks were calculated using the intraclass correlation coefficient and Fleiss κ, respectively. Pearson product moment correlation coefficients between peak joint angles measured during running and the same angles measured during RRS tasks were computed. Peak joint angles of high- and low-scoring participants were compared. RESULTS: Interrater and intrarater reliabilities of assessment of the total RRS scores were good (intraclass correlation coefficients = 0.75 and 0.80, respectively). Reliability of assessing individual tasks was moderate to almost perfect (κ = 0.58-1.00). Peak hip adduction, contralateral pelvic drop, and knee abduction during running were correlated with the same angles measured during hopping, step-ups, and single-legged squats (r = 0.537-0.939). Peak knee internal rotation during running was correlated with peak knee internal rotation during step-ups (r = 0.831). Runners who scored high on the RRS demonstrated less knee abduction during running (P ≤ .01). CONCLUSIONS: The RRS may effectively assess knee abduction in novice runners, but evaluation criteria or tasks may need to be modified to effectively characterize pelvic and transverse-plane knee kinematics.

Disparities in functional recovery after dysvascular lower limb amputation are associated with employment status and self-efficacy.

PURPOSE: Employment status is considered a determinant of health, yet returning to work is frequently a challenge after lower limb amputation. No studies have documented if working after lower limb amputation is associated with functional recovery. The study's purpose was to examine the influence of full-time employment on functioning after lower limb amputation. METHODS: Multisite, cross-sectional study of 49 people with dysvascular lower limb amputation. Outcomes of interest included performance-based measures, the Component Timed-Up-and-Go test, the 2-min walk test, and self-reported measures of prosthetic mobility and activity participation. RESULTS: Average participant age was 62.1 ± 9.7 years, 39% were female and 45% were persons of color. Results indicated that 80% of participants were not employed full-time. Accounting for age, people lacking full-time employment exhibited significantly poorer outcomes of mobility and activity participation. Per regression analyses, primary contributors to better prosthetic mobility were working full-time (R2 ranging from 0.06 to 0.24) and greater self-efficacy (R2 ranging from 0.32 to 0.75). CONCLUSIONS: This study offers novel evidence of associations between employment and performance-based mobility outcomes after dysvascular lower limb amputation. Further research is required to determine cause-effect directionalities. These results provide the foundation for future patient-centered research into how work affects outcomes after lower limb amputation. IMPLICATIONS FOR REHABILITATIONLower limb amputation can pose barriers to employment and activity participation, potentially affecting the quality of life.This study found that the majority of people living with lower limb amputation due to dysvascular causes were not employed full-time and were exhibiting poorer prosthetic outcomes.Healthcare practitioners should consider the modifiable variable of employment when evaluating factors that may affect prosthetic mobility.The modifiable variable of self-efficacy should be assessed by healthcare professionals when evaluating factors that may affect prosthetic mobility.

Current Life Experiences in Veterans with Limb Loss: A Description of Survey Methods and Summary Results.

PURPOSE: To present the methods and summary findings of a nationwide survey on the current life experiences of Operation Iraqi Freedom/Operation Enduring Freedom (OEF/OIF) Veterans with limb loss. METHODS: A questionnaire was sent to Veterans with items covering sample demographics, summaries of health status, prosthesis usage and fit, employment experience, and use and satisfactions with support services and providers. RESULTS: 158 Veterans completed the survey. Approximately 40% perceived their overall status, function and problems related to the prosthesis as "Average". 58% wore a prosthesis over 10 hours per day and 74% did not use additional walking aids. Approximately 75% had at least "Moderate" pain and residual limb health problems. 37% were employed though conditions often changed. Over 80% used healthcare, mental health counseling and education services. The Departments of Defense and VA were primary service providers. CONCLUSIONS: Respondents generally exhibited satisfactory life experiences. Results suggest a positive current status despite challenges that could impair health, functioning and quality of life. Support services were available as needed. Satisfaction with services and providers varied.

Assessing the effects of gait asymmetry: Using a split-belt treadmill walking protocol to change step length and peak knee joint contact force symmetry.

Asymmetrical gait may affect important outcomes such as knee joint contact force (KJCF). A split-belt treadmill (SBTM) can be used to provoke changes in step length symmetry (SLsym) and may produce a similar response in KJCF symmetry (KJCFsym) between limbs. The purpose of this study was to explore the utility of employing a SBTM walking paradigm to alter KJCF and KJCFsym and to determine if changes in SLsym coincided with changes in KJCFsym. Twenty healthy individuals performed a standardized SBTM protocol, where baseline and post-adaptation conditions had tied belt speeds of 0.5 m/s and the split-adaptation condition used a 3:1 belt speed ratio. OpenSim techniques were used to produce normalized, averaged stance phase peak KJCF during baseline walking, early- and late-adaptation, and post-adaptation. SLsym and KJCFsym values were determined. Comparisons were made for symmetry values between early- and late-adaptation and between baseline and post-adaptation. SLsym and KJCFsym did not respond in the same manner during the walking conditions. While step lengths (SL) were asymmetric during early adaptation but become more symmetric by late adaptation (p < 0.01), KJCF was symmetric throughout adaptation. Conversely, SL and KJCF exhibited similar responses during the baseline and post-adaptation conditions, with symmetry at baseline and asymmetry during post-adaptation (p < 0.01). In the post-adaptation condition, higher peak forces were demonstrated on the limb taking a shorter step. Results suggest a SBTM program may alter KJCF and KJCFsym between limbs. Furthermore, a comparison between baseline and post-adaptation may be more appropriate for evaluating the relationship between SL and KJCF.

Comparison of Frontal and Transverse Plane Kinematics Related to Knee Injury in Novice Versus Experienced Female Runners.

Novice runners experience a higher incidence of knee injury than experienced runners, which may be related to aberrant frontal and transverse plane kinematics. However, differences in kinematics between novice and experienced runners have not been fully explored. For this study, 10 novice and 10 experienced female runners ran on a treadmill at 2.68 m/s. Ankle, knee, and hip joint angles during the stance phase were measured using a 3-dimensional motion capture system and modeled using cubic splines. Spline models were compared between groups using a generalized linear model (α = .05). Ninety-five percent confidence intervals of the difference between joint angles throughout stance were constructed to identify specific periods of stance where groups differed in joint position. Angle-angle diagrams of ankle and hip position in the frontal and transverse planes were constructed to depict joint coordination. Novice runners displayed less hip adduction, but greater knee abduction and knee internal rotation compared to experienced runners. Differences in knee joint position may be explained by coordination of hip and ankle motion. Greater knee abduction and knee internal rotation displayed by novice runners compared with experienced runners may help to explain their higher risk for injury.

Accuracy and precision of a wrist movement when vibrotactile prompts inform movement speed.

Purpose: This study investigated the effect of movement speed on task accuracy and precision when participants were provided temporally oriented vibrotactile prompts. Materials and methods: Participants recreated a simple wrist flexion/extension movement at fast and slow speeds based on target patterns conveyed via vibrating motors affixed to the forearm. Each participant was given five performance-blinded trials to complete the task at each speed. Movement accuracy (root mean square error) and precision (standard deviation) were calculated for each trial in both the spatial and temporal domains. Results: 28 participants completed the study. Results showed temporal accuracy and precision improved with movement speed (both: fast > slow, p < 0.01), while all measures improved across trials (temporal accuracy and precision: trial 1 < all other trials, p < 0.05; spatial accuracy: trial 1 and 2 < all other trials, p < 0.05; spatial precision: trial 1 < all other trials, p < 0.05). Conclusions: Overall, temporal and spatial results indicate participants quickly recreated and maintained the desired pattern regardless of speed. Additionally, movement speed seems to influence movement accuracy and precision, particularly within the temporal domain. These results highlight the potential of vibrotactile prompts in rehabilitation paradigms aimed at motor re-education.

The Relationship Between Gait Symmetry and Metabolic Demand in Individuals With Unilateral Transfemoral Amputation: A Preliminary Study.

INTRODUCTION: Temporal-spatial symmetry allows for optimal metabolic economy in unimpaired human gait. The gait of individuals with unilateral transfemoral amputation is characterized by temporal-spatial asymmetries and greater metabolic energy expenditure. The objective of this study was to determine whether temporal-spatial asymmetries account for greater metabolic energy expenditure in individuals with unilateral transfemoral amputation. MATERIALS AND METHODS: The relationship between temporal-spatial gait asymmetry and metabolic economy (metabolic power normalized by walking speed) was retrospectively examined in eighteen individuals with transfemoral amputation walking at a self-selected velocity overground. Pearson's product-moment correlations were used to assess the relationship between: (1) step time symmetry and metabolic economy and (2) step length symmetry and metabolic economy. The retrospective analysis of this data was approved by the Walter Reed National Military Medical Center Institutional Review Board and all individuals provided written consent. Additional insights on this relationship are presented through a case series describing the temporal-spatial and metabolic responses of two individuals with transfemoral amputation who completed a split-belt treadmill walking test. RESULTS: For the cohort of individuals, there was no significant relationship between metabolic economy and either step time asymmetry or step length asymmetry. However, the case series showed a positive relationship between step length asymmetry and metabolic power as participants adapted to split-belt treadmill walking. CONCLUSION: There is mixed evidence for the relationship between temporal-spatial asymmetries and metabolic energy expenditure. This preliminary study may suggest optimal metabolic energy expenditure in individuals with transfemoral amputation occurs at an individualized level of symmetry and resultant deviations incur a metabolic penalty. The results of this study support the idea that addressing only temporal-spatial gait asymmetries in individuals with transfemoral amputation through rehabilitation may not improve metabolic economy. Nevertheless, future prospective research is necessary to confirm these results and implications for clinical practice.

Dynamic stability during split-belt walking and the relationship with step length symmetry.

INTRODUCTION: Walking instability is a contributor to falls and other undesired changes in walking performance. We investigated the effect of split-belt treadmill based perturbations on dynamic stability. Furthermore, we examined the relationships for dynamic stability and symmetry during unperturbed and perturbed walking. METHOD: Twenty healthy young adults completed unperturbed and perturbed walking conditions on a split-belt treadmill. The continuous perturbation involved moving the parallel belts at unequal speeds (1.5 m/s: 0.5 m/s). Margins of stability (MoS) and step length symmetry (SYM) were assessed. RESULTS: Stability and symmetry measures each decreased at the onset of the split walking perturbation. Only anterior-posterior (AP) MoS and SYM exhibited adaptive changes. Associations were found primarily for AP MoS with immediate changes in SYM at the onset of split walking, and over the duration of the split walking condition. DISCUSSION: Our findings suggest walking strategies were adapted to maintain dynamic stability when faced with a continuous perturbation. Additionally, dynamic stability was associated with symmetry during perturbed walking.

Factors Influencing Functional Outcomes and Return-to-Work After Amputation: A Review of the Literature.

Purpose Amputation is a life changing event that can significantly impact an individual's physical and mental well-being. Our objective was to review literature exploring the impact of amputation upon a person's functioning and inclusion in the workplace. Methods Medline, CINAHL, and PsycINFO were searched using keywords related to amputation, employment and community reintegration. Eligible studies were published since 2000 and one of the following study designs: randomized controlled trial, non-randomized controlled trial, retrospective study, prospective study, concurrent cohort study, or cross sectional study. Studies for civilians with amputation as well as service members and Veterans with amputation were considered for inclusion. Results The search identified 995 articles, 25 of which met inclusion/exclusion criteria and were included in the review. While strong evidence for correlations and predictors of outcomes after amputation were limited, multiple factors were identified as contributing to physical functioning and employment after amputation. Conclusions Outcomes after amputation can vary widely with many potentially inter-related factors contributing. The factors identified may also serve to inform the development of interventions aiming to improve functional performance and reintegration after amputation. Furthermore, the review highlights the need for more high quality prospective studies.

Gait and Functional Outcomes for Young, Active Males With Traumatic Unilateral Transfemoral Limb Loss.

OBJECTIVE: Altered body structures that occur with the loss of a lower limb can impact mobility and quality of life. Specifically, biomechanical changes that result from wearing a prosthesis have been associated with an increased risk of falls or joint degeneration, as well as increased energy demands. While previous studies describing these outcomes are typically limited by number of outcome measures and/or small, diverse patient groups, recent military conflicts present a unique opportunity to collect outcomes from a relatively homogenous, active patient population with limb loss. Thus, the objective of this study is to provide reference outcome measures on the basis of a large, relatively homogenous cohort of military personnel with transfemoral limb loss. METHODS: A retrospective review of biomechanical, physiological, functional, and subjective measures was completed for 67 male servicemembers who sustained an injury resulting in traumatic, transfemoral limb loss during recent conflicts. These individuals represent a defined cohort, capable of exhibiting improved clinical outcomes resulting from demographic characteristics and extensive rehabilitation. Biomechanical and physiological outcome measures for 76 uninjured male servicemembers are also provided to serve as normative reference for full return to function. Select biomechanical and physiological outcomes related to stability, overuse, and efficiency are discussed in the text, on the basis of relevance to clinical gait assessment, in addition to functional and subjective measures. RESULTS: In general, individuals with transfemoral limb loss exhibit decreased stability relative to uninjured individuals, noted by larger peak trunk velocity and step width variability; increased risk of low back and knee joint pain and/or degeneration, noted by larger trunk lateral flexion and bending moments, as well as larger vertical ground reaction force (vGRF) loading rates and impulses, respectively; and decreased efficiency during gait, noted by larger oxygen costs and leading limb mechanical work. CONCLUSION: Although the comprehensive set of measures presented here indicates overall reductions in biomechanical and functional performance with transfemoral limb loss compared to uninjured individuals, these reductions were relatively smaller than existing evidence among populations that are more diverse in age and activity level. Therefore, this data set may be used as benchmarks for young, active individuals with transfemoral limb loss, to assist with setting clinical goals, and to aid in the evaluation of new treatment techniques or interventions. These measures will also be particularly important for subsequent evaluations and longitudinal follow-ups to determine the longer-term impact of transfemoral limb loss on this cohort.

Locomotor adaptability in persons with unilateral transtibial amputation.

BACKGROUND: Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. OBJECTIVE: Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). METHODS: The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. RESULTS: Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. CONCLUSIONS: Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb.

Can real-time visual feedback during gait retraining reduce metabolic demand for individuals with transtibial amputation?

The metabolic demand of walking generally increases following lower extremity amputation. This study used real-time visual feedback to modify biomechanical factors linked to an elevated metabolic demand of walking in individuals with transtibial amputation. Eight persons with unilateral, traumatic transtibial amputation and 8 uninjured controls participated. Two separate bouts of real-time visual feedback were provided during a single session of gait retraining to reduce 1) center of mass sway and 2) thigh muscle activation magnitudes and duration. Baseline and post-intervention data were collected. Metabolic rate, heart rate, frontal plane center of mass sway, quadriceps and hamstrings muscle activity, and co-contraction indices were evaluated during steady state walking at a standardized speed. Visual feedback successfully decreased center of mass sway 12% (p = 0.006) and quadriceps activity 12% (p = 0.041); however, thigh muscle co-contraction indices were unchanged. Neither condition significantly affected metabolic rate during walking and heart rate increased with center-of-mass feedback. Metabolic rate, center of mass sway, and integrated quadriceps muscle activity were all not significantly different from controls. Attempts to modify gait to decrease metabolic demand may actually adversely increase the physiological effort of walking in individuals with lower extremity amputation who are young, active and approximate metabolic rates of able-bodied adults.

Axial bone-socket displacement for persons with a traumatic transtibial amputation: The effect of elevated vacuum suspension at progressive body-weight loads.

BACKGROUND: Elevated vacuum suspension systems use a pump to draw air from the socket with the intent of reducing bone-socket motion as compared to passive suction systems. However, it remains unknown if elevated vacuum suspension systems decrease limb displacement uniformly during transitions from unloaded to full-body-weight support. OBJECTIVES: To compare limb-socket motion between elevated vacuum and passive suction suspension sockets using a controlled loading paradigm. STUDY DESIGN: Comparative analysis. METHODS: Persons with transtibial amputation were assessed while wearing either an elevated vacuum or passive suction suspension socket. Digital video fluoroscopy was used to measure axial bone-socket motion while the limb was loaded in 20% body-weight increments. An analysis of variance model was used to compare between suspension types. RESULTS: Total axial displacement (0%-100% body weight) was significantly lower using the elevated vacuum (vacuum: 1.3 cm, passive suction: 1.8 cm; p < 0.0001). Total displacement decreased primarily due to decreased motion during initial loading (0%-20%; p < 0.0001). Other body-weight intervals were not significantly different between systems. CONCLUSION: Elevated vacuum suspension reduced axial limb-socket motion by maintaining position of the limb within the socket during unloaded conditions. Elevated vacuum provided no meaningful improvement in limb-socket motion past initial loading. CLINICAL RELEVANCE: Excessive bone-socket motion contributes to poor residual limb health. Our results suggest elevated vacuum suspensions can reduce this axial displacement. Visual assessment of the images suggests that this occurs through the reduction or elimination of the air pocket between the liner and socket wall while the limb is unloaded.

Biomechanical measures in participants with shoulder pain: Intra-rater reliability.

Biomechanical measures are used to characterize the mechanisms of treatment for shoulder pain. The objective was to characterize test-retest reliability and measurement error of shoulder surface electromyographic(sEMG) and kinematic measures. Individuals(n = 12) with subacromial pain syndrome were tested at 2 visits. Five repetitions of shoulder scapular plane elevation were performed while collecting sEMG of the upper trapezius(UT), middle trapezius(MT), lower trapezius(LT), serratus anterior(SA) middle-deltoid, and infraspinatus muscles during ascending and descending phases. Simultaneously, electromagnetic sensors measured 3-dimensional kinematics of scapular internal/external rotation, upward/downward rotation, posterior/anterior tilt, and clavicular elevation/depression and clavicular protraction/retraction. Kinematic and sEMG variables were reduced for the total phase of ascending and descending elevation (30°-120°, 120°-30°), at 30° intervals for sEMG, and at every 30° discrete kinematic angle. The intraclass correlation coefficients(ICC) ranged from 0.08 to 0.99 for sEMG and 0.23-0.95 for kinematics. Correspondingly, the standard error of the measurement(SEM) and minimal detectable change(MDC) for sEMG measures varied from 2.3% to 103.8% of a reference contraction(REF-contraction). For kinematics, the SEM and MDC varied from 1.4° to 5.9°. Between-day reliability was good to very good, except for scapular internal/external rotation kinematics, and sEMG for the LT, UT, and SA. sEMG error values were highest (>25%REF-contraction) for most of the LT, UT, and SA variables. Kinematic error values indicate changes or differences of 2°-3° are meaningful, except for upward/downward rotation and internal/external rotation with MDCs of 4°-6°. Generally, data from the total phase of movement had better reliability and lower error than the data from sEMG interval or kinematic discrete angles.

Assessing preparative gait adaptations in persons with transtibial amputation in response to repeated medial-lateral perturbations.

Preventing loss of balance in individuals with transtibial amputation is important, as they are susceptible to a high frequency of fall related injuries. In order to validate fall prevention and balance therapies, methods to assess gait stability must be developed. Kinematic, temporal-spatial, and center of mass data from six healthy young participants with transtibial amputation were collected during treadmill walking during exposure to 10 randomly ordered discrete medial-lateral perturbations. The 20 strides prior to each perturbation were assessed for anticipatory changes. The only consistent postural adjustment made as a result of the perturbations was a significantly lowered center of mass height (p=0.016).

Energetic consequences of using a prosthesis with adaptive ankle motion during slope walking in persons with a transtibial amputation.

BACKGROUND: Technological advances in prosthetic design include the use of microprocessors that adapt device performance based on user motion. The Proprio ankle unit prepositions the foot to adjust for walking on slopes and increases foot clearance during swing to minimize gait deviations. STUDY DESIGN: Comparative analysis. OBJECTIVES: To investigate the effect of a prosthesis with adaptive ankle motion on physiological gait performance during slope walking. METHODS: Six persons with a unilateral transtibial amputation completed treadmill walking tests at three slopes (-5°, 0°, and 5°). The participants were tested wearing a customary device, active Proprio (Pon), and an identical inactivated Proprio (Poff). RESULTS: Metabolic energy expenditure, energy cost for walking, and rating of walking difficulty were not statistically different between the Pon and Poff for all tested slopes. However, for slope descent, energy expenditure and energy cost for walking improved significantly by an average of 10%-14% for both the Pon and Poff compared to the customary limb. Rating of walking difficulty also showed an improvement with slope descent for both the Pon and Poff compared to the customary device. An improvement with slope ascent was found for Pon compared to the customary limb only. CONCLUSIONS: Adaptive ankle motion provided no meaningful physiological benefit during slope walking. The Proprio was, however, less demanding than the customary device for slope descent. Differences in the mechanical properties of the prosthetic feet likely contributed to the changes. CLINICAL RELEVANCE: While the adaptive ankle motion did not affect metabolic energy expenditure or energy cost for walking, the results suggest close attention should be paid to the mechanical properties of the foot component. Assessment of gait on nonlevel surfaces is recommended to better understand the implications of different prosthetic design features.

Home-based treadmill training to improve gait performance in persons with a chronic transfemoral amputation.

OBJECTIVE: To investigate the effectiveness of a home-based multiple-speed treadmill training program to improve gait performance in persons with a transfemoral amputation (TFA). DESIGN: Repeated measures. SETTING: Research laboratory. PARTICIPANTS: Individuals with a TFA (N=8) who had undergone a unilateral amputation at least 3 years prior as a result of limb trauma or cancer. INTERVENTION: Home-based treadmill walking for a total of 30 minutes a day, 3 days per week for 8 weeks. Each 30-minute training session involved 5 cycles of walking for 2 minutes at 3 speeds. MAIN OUTCOME MEASURES: Participants were tested pretraining and after 4 and 8 weeks of training. The primary measures were temporal-spatial gait performance (symmetry ratios for stance phase duration and step length), physiological gait performance (energy expenditure and energy cost), and functional gait performance (self-selected walking speed [SSWS], maximum walking speed [MWS], and 2-minute walk test [2MWT]). RESULTS: Eight weeks of home-based training improved temporal-spatial gait symmetry at SSWS but not at MWS. A relative interlimb increase in stance duration for the prosthetic limb and proportionally greater increases in step length for the limb taking shorter steps produced the improved symmetry. The training effect was significant for the step length symmetry ratio within the first 4 weeks of the program. Energy expenditure decreased progressively during the training with nearly 10% improvement observed across the range of walking speeds. SSWS, MWS, and 2MWT all increased by 16% to 20%. CONCLUSIONS: Home-based treadmill walking is an effective method to improve gait performance in persons with TFA. The results support the application of training interventions beyond the initial rehabilitation phase, even in individuals considered highly functional.