Self-selected Walking Velocity Research Articles

Biomechanical differences between self-paced and fixed-speed treadmill walking in persons after stroke.

Using self-paced treadmills for gait analysis requires less space compared to overground gait labs while a more natural walking pattern could be preserved compared to fixed-speed treadmill walking. Although self-paced treadmills have been used in stroke related intervention studies, studies comparing self-paced to fixed-speed treadmill walking in this population are scarce. Twenty-five persons after stroke (10 males/15 females; 53±12.05years; 40.72±42.94months post stroke) walked on a treadmill in a virtual environment (GRAIL, Motek) in two conditions (self-paced and fixed-speed). After familiarization, all participants completed two trials (3min) at comfortable walking velocity in randomized order. A paired-sample t-test or Wilcoxon Signed Rank test was used to calculate differences between both conditions for spatiotemporal parameters. Statistical Parametric mapping was conducted using the t-tests (SPM(t)), to statistically compare the kinematic and kinetic curves. The self-selected walking velocity on the treadmill was higher in the self-paced condition compared to the fixed-speed condition (p<0.001). However, most variability and symmetry measures were similar in both conditions. Only the standard deviation of the step length at the paretic side was significant higher (p=0.007) and step length symmetry was significantly better (p=0.032) in the self-paced condition. Detected kinematic and kinetic differences were small (< 3°, < 0.1Nm/kg) and stride to stride variability was comparable in both conditions. Based on the results of the current study, self-paced walking can be used as an equivalent to fixed-speed treadmill walking in persons after stroke. Accordingly, this justifies the use of this more functional mode in clinical gait assessment and rehabilitation trials.

Biomechanical accommodation to walking with an ankle-foot prosthesis: An exploratory analysis of novice users with transtibial limb loss within the first year of ambulation.

The way in which a person with limb loss interacts with a prosthesis changes over time; however, there remains a lack of guidance for defining accommodation to walking with a prosthesis, limiting consistency and generalizability of research. To evaluate accommodations to walking with dynamic elastic response prosthetic ankle-foot devices among novice users with unilateral transtibial limb loss during the first year of ambulation. This is a retrospective cohort study. Prosthetic and intact ankle-foot mechanical power profiles and mechanical work during step-to-step transitions were calculated using the Unified Deformable model for 22 male individuals with limb loss at five time points within the first year of independent ambulation (0, 2, 4, 6, and 12 months). Subjects walked at a self-selected walking velocity and controlled walking velocity (CWV). Subjective measures included the Prosthetic Evaluation Questionnaire and the 36-Item Short-Form Health Survey. Self-selected walking velocity ranged from 1.24 ± 0.06 m/s at 0 month to 1.38 ± 0.04 m/s at 12 months, whereas CWV was 1.20 ± 0.02 m/s. At both velocities, positive work/peak power during prosthetic push-off trended upward until the 4-month time point. In addition, negative peak power during intact foot-strike seemed to qualitatively become less negative until 4 months. Positive work during intact push-off trended downward until 4 months at CWV, whereas positive peak power during intact push-off qualitatively became more positive at self-selected walking velocity. These trends may partially indicate (biomechanical) accommodation to walking by appearance of a "plateau" at 4 months after initial ambulation with a prosthesis.

The effect of a multi-modal boxing exercise program on cognitive locomotor tasks and gait in persons with Parkinson disease.

Parkinson disease (PD) is a progressive neurological disease resulting in motor impairments, postural instability, and gait alterations which may result in self-care limitations and loss of mobility reducing quality of life. This study's purpose was to determine the impact of a community-based boxing program on gait parameters, dual task and backwards walking in individuals with PD. This study included 26 community dwelling individuals with PD who participated in 12-week boxing classes (1 hour, 2 times a week). The focus was on upper/lower extremity exercises using punching bags, agility drills, and strengthening activities. Pre/post testing was performed for dual task and gait parameters and was analyzed using t-tests. Analysis of the scores indicated participants performed significantly better at post-test compared to pre-test on self-selected walking velocity (P = 0.041), cadence (P = 0.021); backwards walking velocity (P = 0.003), step length (P = 0.022); dual task walking velocity (P = 0.044), step length (P = 0.023), and gait variability index (P = 0.008). No significant differences for fast walking. Multi-modal boxing produced improvements in gait velocity, dual task velocity, step length, and gait variability, as well as backwards walking velocity and step length. These improvements may impact independence with functional mobility and may improve safety but require further studies.

Factors associated with walking activity in adults with cerebral palsy.

This prospective study used instrumented gait analysis, patient-reported outcomes, and portable accelerometers to examine walking activity in adults with cerebral palsy (CP). This study aimed to provide objective data and evaluate factors associated with walking activity in adults with CP. Participants with CP (ages 25-45 years) completed instrumented gait analysis and patient-reported outcomes, including the Patient Reported Outcome Measurement Information System (PROMIS) and Satisfaction with Life Score (SWLS), and wore a StepWatch for 8 days. Average strides per day, stratified by Gross Motor Function Classification System (GMFCS), were compared with nondisabled adults ages 30-39 years utilizing Welch's t-tests with Bonferroni corrections. Correlation coefficients and stepwise multiple linear regression analyses examined relationships between walking activity and GMFCS, gait deviation index (GDI), gait velocity, PROMIS physical function, SWLS, body mass index (BMI), and employment. Participants included 109 adults with CP, ages 29 ± 4 years, classified at GMFCS levels I/II (73 %) and III/IV (27 %). Compared with nondisabled adults, daily stride count was significantly lower in both groups of adults with CP (p < 0.00025), with a progressive decline according to GMFCS level. Walking activity correlated with PROMIS physical function (r = .42), GDI (r = .48), and gait velocity (r = .58). Association for employment was lower (r = 0.27) but significant, while age, SWLS, and BMI were not individually correlated with walking activity. Stepwise, multiple linear regression modeled with Akaike information criterion explained 40.9 % of the observed variability in walking activity in this cohort of adults with CP. Physical function, as classified by GMFCS or measured by PROMIS and self-selected walking velocity, has the strongest association with and is the most significant predictor of walking activity in adults with CP. After accounting for physical function, a small amount of the variation in walking activity can be explained by GDI, employment, and age.

CORR Insights®: Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population.

CORR Insights®: Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population.

Validity of the Polar V800 Monitor for Assessing Heart Rate Variability in Elderly Adults under Mental Stress and Dual Task Conditions.

Background: Aging may result in autonomic nervous dysfunction. Heart rate variability (HRV) is a non-invasive method to measure autonomic nervous activities. Many studies have shown that HRV contributes to the risk assessment of diseases. A Polar V800 heart rate monitor is a wearable device that measures R-R intervals, but has only been validated in younger adults under limited testing conditions. There is no validation of the V800 under mental stress or in dual task testing conditions. Therefore, this study investigated the validity of the Polar V800 heart rate monitor for assessing R-R intervals and evaluated if there were differences on HRV parameters under different situations in community-dwelling elderly adults. Methods: Forty community-dwelling elderly adults were recruited. Heart rates were recorded via electrocardiogram (ECG) and the V800 under sitting, during an arithmetic test, during a naming test, a self-selected walking velocity test (SSWV), and dual tasks (SSWV performing mental arithmetic test and SSWV performing naming test). Indices of time and frequency domains of HRV were calculated afterwards. The intra-class correlation coefficient (ICC) analysis and effect size were calculated to examine the concurrent validity between the V800 and the ECG. Results: All HRV indices from the V800 were highly correlated with the ECG under all tested conditions (ICC = 0.995–1.000, p < 0.001) and the effect size of bias was small (<0.1). Conclusion: Overall, the V800 has good validity on the assessment of HRV in community-dwelling elderly adults during sitting, mental arithmetic test, naming test, SSWV, and dual tasks.

The mechanics behind gait problems in patients with Dravet Syndrome

BackgroundDravet Syndrome (DS) is a developmental and epileptic encephalopathy starting in infancy and characterised by treatment resistant epilepsy with cognitive impairment and progressive motor dysfunction. Walking becomes markedly impaired with age, but the mechanical nature of gait problems remains unclear. Research questionWhat are the kinetic strategies characterised in gait of patients with DS? MethodsThis case-control study compared 41 patients with DS aged 5.2–26.1 years (19 female, 22 male) to 41 typically developing (TD) peers. Three dimensional gait analysis (VICON) was performed to obtain spatiotemporal parameters, kinematics and kinetics during barefoot, level walking at self-selected walking velocity. The sagittal plane support moment was analysed using Statistical Parametric Mapping (SPM). Three DS subgroups were identified based on differences in kinetic strategies characterised by the net internal knee joint moments and trunk lean. Kinematic and kinetic time profiles of the subgroups were compared to the TD group (SPM t-test). Clinical characteristics from physical examination and parental anamnesis were compared between DS (sub)groups using non-parametric tests (Kruskal-Wallis, Wilcoxon rank-sum, Fisher’s exact). ResultsSupport moments in stance were significantly increased in the DS group compared to TD and strongly related to minimum knee flexion in midstance. Persistent internal knee extension moments during stance were detected in a subgroup of 27 % of the patients. A second subgroup of 34 % showed forward trunk lean and attained internal knee flexion moments. The remaining 39 % had neutral or backward trunk lean with internal knee flexion moments. Subgroups differed significantly in age and functional mobility. SignificanceInefficient kinetic patterns suggested that increased muscle effort was needed to control lower limb stability. Three distinct kinetic strategies that underly kinematic deviations were identified. Clinical evaluation of gait should pay attention to knee angles, trunk lean and support moments.

Changes in Trunk and Pelvis Motion Among Persons With Unilateral Lower Limb Loss During the First Year of Ambulation

ObjectiveTo retrospectively investigate trunk-pelvis kinematic outcomes among persons with unilateral transtibial and transfemoral limb loss with time from initial independent ambulation with a prosthesis, while secondarily describing self-reported presence and intensity of low back pain. Over time, increasing trunk-pelvis range of motion and decreasing trunk-pelvis coordination with increasing presence and/or intensity of low back pain were hypothesized. Additionally, less trunk-pelvis range of motion and more trunk-pelvis coordination for persons with more distal limb loss was hypothesized. DesignInception cohort with up to 5 repeated evaluations, including both biomechanical and subjective outcomes, during a 1-year period (0, 2, 4, 6, 12 months) after initial ambulation with a prosthesis. SettingBiomechanics laboratory within military treatment facility. ParticipantsTwenty-two men with unilateral transtibial limb loss and 10 men with unilateral transfemoral limb loss (N=32). InterventionsNot applicable. Main Outcome MeasuresTriplanar trunk-pelvis range of motion and intersegmental coordination (continuous relative phase) obtained at self-selected (∼1.30m/s) and controlled (∼1.20m/s) walking velocities. Self-reported presence and intensity of low back pain. ResultsAn interaction effect between time and group existed for sagittal (P=.039) and transverse (P=.009) continuous relative phase at self-selected walking velocity and transverse trunk range of motion (P=.013) and sagittal continuous relative phase (P=.005) at controlled walking velocity. Trunk range of motion generally decreased, and trunk-pelvis coordination generally increased with increasing time after initial ambulation. Sagittal trunk and pelvis range of motion were always less and frontal trunk-pelvis coordination was always greater for persons with more distal limb loss. Low back pain increased for persons with transtibial limb loss and decreased for persons with transfemoral limb loss following the 4-month time point. ConclusionsTemporal changes (or lack thereof) in features of trunk-pelvis motions within the first year of ambulation help elucidate relationships between (biomechanical) risk factors for low back pain after limb loss.

Foot and Ankle Patients Prefer a Hands-Free Single Crutch Compared to Standard Axillary Crutches

Category: Ankle Introduction/Purpose: Following lower extremity surgery patients are often required to utilize assistive devices in order to perform activities of daily living. As technology and assistive devices continue to improve, providers are faced with selecting a device that is safe while providing high patient satisfaction and a quick return to actives. The purpose of the current study was to compare physical exertion and subject preference between a hands-free single crutch and standard axillary crutches in foot and ankle patients. Methods: A prospective, randomized crossover study was performed using 35 orthopedic foot and ankle patients from within one treatment facility. Each participant had demographic data and heart rate recorded. The patients were then randomized to an assistive device. All participants completed a 6-minute walk test (6MWT); immediately following each 6MWT heart rate, self-selected walking velocity (SSWV), perceived exertion using OMNI Rating of Perceived Exertion (OMNI-RPE) and perceived dyspnea using Modified Borg Dyspnea Scale was obtained. The patients then completed another 6MWT using the other assistive device and was asked the same questions. After completing both 6MWTs participants were asked which assistive device they would prefer to use. Results: A total of 35 patients were included with a median age of 32-year-old. The hands-free crutch was preferred by 86% of participants. Regression analysis was used to test if factors such as gender, height, weight, BMI predicted patient preference of iWalk vs. Crutch. None of these factors were found to be significant. Student t-tests and ANOVAs were performed separately for dyspnea, fatigue ratings, distance (meters) and heart rate between iWalk and crutch all were found to be significant (p&lt;0.05, p=1.13e-11, p=2.29e-13, p=5.21e-05, respectively). The axillary crutch group had higher SSWV (0.8 vs 0.77m/s) but was not found to be significant. Neither group had any falls, however, 58% of axillary participants complained of axillary/hand pain while the hands-free group had 14% complain of proximal strap discomfort. Conclusion: Patients preferred the hands-free crutch while reporting lower perceived dyspnea and fatigue. The hands-free group demonstrated lower physiologic demand, which correlated with patient perception.

Assessment of Disability Related to Femoroacetabular Impingement Syndrome by Use of the Patient-Reported Outcome Measure Information System (PROMIS) and Objective Measures of Physical Performance

Background: The National Institutes of Health (NIH)–sponsored Patient-Reported Outcomes Measurement System (PROMIS) has been described as a valuable tool for characterizing outcomes among patients with specific musculoskeletal conditions. Additionally, previously proposed objective measures of physical performance among patients with nonarthritic hip abnormalities are costly and not practically incorporated into routine clinical practice. Purpose: (1) To determine the ability of the PROMIS to differentiate between patients with femoroacetabular impingement (FAI) and asymptomatic controls, (2) to determine the effect of FAI on subjects’ completion of timed physical performance measures, and (3) to determine whether associations exist between established patient-reported outcome (PRO) measures and subjects’ completion of physical performance measures. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-two asymptomatic controls (CON group) and 20 patients with FAI completed multiple activities to assess physical ability: self-selected walking velocity (SSWV), timed stair ascent (TSA), four-square step test (FSST), and sit-to-stand five times test (STS5). All subjects also underwent a battery of PRO questionnaires: Visual Analog Scale for Pain (VAS), Modified Harris Hip Score (mHHS), International Hip Outcome Tool (iHOT-33), Hip Disability and Osteoarthritis Outcome Score (HOOS), and PROMIS. Descriptive analyses were performed and comparisons between groups were made by use of paired t tests with Bonferroni-Holm correction. Spearman’s rank correlation coefficients were used to determine associations between physical performance measures and PRO. The magnitude of differences between groups for each measured variable was calculated by use of Cohen’s d. Results: Significant differences between CON and FAI groups were observed for all hip-specific PRO measures (CON vs FAI for all; HOOS 99.2 vs 42.8, P < .001, iHOT-33 99.0 vs 26.6, P < .001, mHHS 99.6 vs 62.2, P < .001). Similarly, PROMIS scores were significantly different between groups for 8 of 9 tested domains. Patients with FAI demonstrated significant decrements in performance of all tested physical measures compared with asymptomatic controls (CON vs FAI, SSWV: 1.51 vs 1.32 m/s, P = .002; TSA: 3.05 vs 5.92 s, P = .017; FSST: 4.83 vs 8.89 s, P = .006; STS5: CON 5.53 vs FAI 10.75 s, P = .005.) Deficits in activities involving hip flexion—TSA, STS5—were strongly associated (r < –0.7, P < .001) with increased reports of disability. Conclusion: FAI has a negative effect on patient-reported and objectively measured function. Hip-specific and general measures such as PROMIS, FSST, TSA, and STS5 are responsive to FAI-associated debility and may be used to objectively assess surgical or rehabilitative outcomes.

Comparative Study of Assisted Ambulation and Perceived Exertion With the Wheeled Knee Walker and Axillary Crutches in Healthy Subjects.

Functional limitations after lower extremity surgery often require the use of an assistive device for ambulation during rehabilitation and recovery. There are no known objective data evaluating the wheeled knee walker as an assistive device for protected ambulation. The purpose of this study was to compare assisted ambulation and perceived exertion with the wheeled knee walker and the axillary crutches in healthy participants. A prospective, randomized crossover study was performed using 24 healthy volunteers. Each participant performed a 6-minute walk test (6MWT) using each assistive device in a crossover manner. Preactivity and postactivity heart rates were recorded. The self-selected walking velocity (SSWV) was calculated and the participant's rating of perceived exertion was recorded using the OMNI Rating of Perceived Exertion (OMNI-RPE). Participant's preference for assistive device was identified. The 6MWT, SSWV, and the Omni-RPE were evaluated using paired t tests and determined to be statistically significant for the wheeled knee walker compared with axillary crutches. Evaluation of the preactivity and postactivity heart rates demonstrated a statistically significant difference for the wheeled knee walker compared with axillary crutches. The wheeled knee walker was preferred by 88% of participants. The wheeled knee walker provided increased assisted ambulation and had a lower rating of perceived exertion than axillary crutches on level surfaces in healthy participants. Level III, comparative study.

Comparative Study of Mobility and Perceived Exertion for the Wheeled Knee Walker and Axillary Crutches in Healthy Participants

Category: Other Introduction/Purpose: Functional limitations are common after lower extremity surgery and often require the use of an assistive device for ambulation during rehabilitation and recovery. There is no known data evaluating the wheeled knee walker (WKW) as an assistive device for postoperative protected ambulation. The purpose of this study is to compare mobility and perceived exertion in the WKW and the axillary crutch (AC) in healthy volunteers. Methods: This is a cross sectional study of the WKW and the AC that was performed on 24 healthy volunteers utilizing the Six- Minute Walk Test (6MWT). The participants were randomized into two separate arms, one starting with the AC (N=12) and one starting with the WKW (N=12). A modified version of the American Thoracic Society (ATS) Guidelines for the 6MWT was performed for both assistive devices on all subjects. Pre-activity and post-activity heart rates were recorded for both events. From the 6MWT data the values for the Self Selected Walking Velocity (SSWV) were calculated and the subjects rating of perceived exertion was recorded using the OMNI Rating of Perceived Exertion (OMNI-RPE). Patient's preference for assistive device was identified. Results: The 6MWT, SSWV and the Omni-RPE were evaluated using paired T-tests and was determined to be statistically significant for the WKW when compared to the AC (p &lt; 0.001). The confounding effect of the sequences were measured utilizing a mixed-model 2x2 ANOVA and was determined to have no significant 3 way (time x device x sequence) interaction (p = 0.968). Factorial 2 x 2 repeated measures ANOVA was used to evaluate the pre-activity and post-activity heart rates and demonstrated a statistically significant difference for the WKW when compared to the AC (p &lt; 0.001). 87.5% of subjects preferred the WKW to the AC. Conclusion: The WKW provided increased mobility and had a lower rating of perceived exertion than the AC on level surfaces in healthy participants

Measurements scales for associated reactions of the upper limb in stroke and traumatic brain injury (TBI): a systematic review

held dynamometry was used to measure ankle plantarflexor strength. Three dimensional gait analysis was performed to quantify APG at push off during walking. Mobility performance was quantified by self-selected walking speed. Results: Ankle plantarflexor strength of the affected leg was only moderately correlated with APG at push-off (r= 0.43, p< 0.001; 95% CI 0.26–0.58). There was also a moderate correlation between ankle plantarflexor strength and self-selected walking velocity (r= 0.32, p= 0.002; 95% CI 0.13 to 0.48). Conclusion(s): Hand held dynamometry measures of ankle plantarflexor strength are only moderately correlated with APG during walking. This clinical test of ankle plantarflexor strength is a poor predictor of ankle plantarflexor muscle function during gait. APG is a strong determinant of gait speed and in people with TBI. Implications: Further research is required, focusing on developing clinically feasible ankle plantar flexor muscle strength testingmethods that are functionallymeaningful and reflect the muscle’s performance during gait.

Clinical tests of ankle plantarflexor strength do not predict ankle power generation during walking

OBJECTIVE The aim of this study was to investigate the relationship between a clinical test of ankle plantarflexor strength and ankle power generation (APG) at push-off during walking. DESIGN This is a prospective cross-sectional study of 102 patients with traumatic brain injury. OUTCOME MEASURES Handheld dynamometry was used to measure ankle plantarflexor strength. Three-dimensional gait analysis was performed to quantify ankle power generation at push-off during walking. RESULTS Ankle plantarflexor strength was only moderately correlated with ankle power generation at push-off (r = 0.43, P < 0.001; 95% confidence interval, 0.26-0.58). There was also a moderate correlation between ankle plantarflexor strength and self-selected walking velocity (r = 0.32, P = 0.002; 95% confidence interval, 0.13-0.48). CONCLUSIONS Handheld dynamometry measures of ankle plantarflexor strength are only moderately correlated with ankle power generation during walking. This clinical test of ankle plantarflexor strength is a poor predictor of calf muscle function during gait in people with traumatic brain injury.

Effects Of Dual-tasking On Stability During Walking In Children With Cerebral Palsy

Background: Many children with Cerebral Palsy (CP) have impaired walking abilities associated with poor maintenance of balance. Such impairments unseen in typically developing children include reduced walking speed, reduced step length, and wider step width. Further, dual-tasking has been associated with reductions in walking speed, stride length, step width and toe clearance compared to normal walking in children with CP but not in typically developing children. However, little is known about the effects of dual-tasking on other balance characteristics during walking in this population. PURPOSE: To examine the effects of dual-tasking on stability (dynamic balance) during walking in children with CP. METHODS: Five assenting children with CP (four boys, one girl; 7.0 ± 0.9 yrs, 125.7 ± 6.5 cm, 26.0 ± 4.5 kg) participated in the experiment and walked four times across a 3.4 m GAITRite® instrumented walkway system (CIR Systems Inc., GAITRite, Sparta, NJ; 120 Hz) at their self-selected speed. Next, participants completed the same walking protocol while simultaneously carrying a tray, similar to what they might do in a school lunchroom. Foot pressure data were extracted and analyzed by footfall (minimum 12 strides per participant) to compare velocity, unilateral step width, stride width, and base of support width for each condition. Data were evaluated using a single-subject procedure (Model Statistic, α = 0.05). RESULTS: Walking velocity decreased significantly when dual tasking for two children (44.0 cm/sec and 40.7 cm/sec, respectively; p < 0.05) while two other children elicited a significant velocity increase (9.4 cm/sec and 12.5 cm/sec, respectively; p < 0.05). Three children reduced base of support when dual-tasking (2.9 ± 2.8 cm, 5.1 ± 4.2 cm, 7.6 ± 7.5 cm, respectively; p < 0.05). Stride width was reduced in two children as a result of the dual-tasking condition (3.7 ± 1.8 cm and 2.3 ± 3.2 cm, respectively; p < 0.05), and one of five children showed reduced step width (9.7 ± 5.1 cm; p < 0.05). CONCLUSION: This dual-tasking condition significantly altered dynamic balance characteristics in children with CP, most notably velocity, base of support, and stride width. Whether this was a function of the observed change in self-selected walking velocity or a characteristic of the population warrants further investigation.

Clinical tests of ankle plantarflexor strength do not predict ankle power generation during walking.

The aim of this study was to investigate the relationship between a clinical test of ankle plantarflexor strength and ankle power generation (APG) at push-off during walking. This is a prospective cross-sectional study of 102 patients with traumatic brain injury. Handheld dynamometry was used to measure ankle plantarflexor strength. Three-dimensional gait analysis was performed to quantify ankle power generation at push-off during walking. Ankle plantarflexor strength was only moderately correlated with ankle power generation at push-off (r = 0.43, P < 0.001; 95% confidence interval, 0.26-0.58). There was also a moderate correlation between ankle plantarflexor strength and self-selected walking velocity (r = 0.32, P = 0.002; 95% confidence interval, 0.13-0.48). Handheld dynamometry measures of ankle plantarflexor strength are only moderately correlated with ankle power generation during walking. This clinical test of ankle plantarflexor strength is a poor predictor of calf muscle function during gait in people with traumatic brain injury.

Gait Mechanics Are Different Between Healthy Controls and Patients With Multiple Sclerosis

Multiple sclerosis (MS) causes severe gait problems in relatively young individuals, yet there have been limited studies to quantitatively identify the specific gait parameters that are affected. The purpose of this study was to define any differences in biomechanical gait parameters between patients with MS and healthy controls. A total of 31 MS patients and 31 healthy controls were evaluated: joint torques and joint powers were calculated at the ankle, knee, and hip during the stance phase of gait. The self-selected walking velocity was used as a covariate in the analysis to ensure that group differences were not due to differences in walking velocity between the MS and healthy control groups. Reduced angular range, less joint torque, and reduced joint power were seen in patients with MS. We also found significant correlations between biomechanical gait parameters and EDSS score, which provides a clinical rating of disease severity. Our findings provide a quantitative assessment of the gait mechanics employed in patients with MS. The altered lower extremity mechanics observed in patients with MS reflect both a neurological and strength deficit compared with healthy controls during walking.

Comparison of energy cost in transtibial amputees using “prosthesis” and “crutches without prosthesis” for walking activities

BackgroundIn a survey of 100 transtibial amputees (TTA) in the study place, it was noticed that nearly 30% of total activities performed by crutches. It was recorded nearly 52% of the amputees were totally independent, 39% had to use a crutch or cane and only 9% need not used any devices simply because they are unaware of current technology or availability. Out of 39 TTA, nine used crutches only for performing daily activities while 30 used both prosthesis and crutch. Walking is a major activity in lower limb amputees and therefore it is imperative to know the energy cost in both the mobility devices (prosthesis and crutches without prosthesis) for walking activities. ObjectivesThe purpose of this study was to quantify and compare the difference in energy cost between the two most commonly used assistive devices (prosthesis and axillary crutches) in adults with Transtibial amputation by indirect calorimetric method at the self-selected speed in plane surface walking. MethodsThirty adults who had a unilateral transtibial amputation participated in this study. Oxygen consumption was measured with a Cosmed K4 b2 oxygen analysis telemetry unit (Rome, Italy) as the participants walked over level ground for 30 meters at a self-selected speed. The variables that were analyzed were VO2 rate (mL/min), VO2 cost (mL/kg/m), heart rate (bpm), self-selected walking velocity (m/min) and energy expenditure per minute (Kcal/min). ResultsIt was observed that VO2 uptake rate and EE comparisons were highly significant for both prosthesis and crutches without prosthesis walking in adults with transtibial amputation (P<0.025). There was significant difference between prosthesis walking and crutches without prosthesis walking in terms of VO2 uptake rate (P<0.005) and EE/min (P<0.00001). It was noticed the adults with transtibial amputation using prosthesis walked with 21% more efficient in terms of VO2 uptake rate and 92% more efficient in terms of EE/min as compared to crutches without prosthesis. ConclusionsThe data on energy cost indicates that all below knee amputee groups walk with less effort by using prosthesis. It may be concluded that crutches without prosthesis may not be used as a permanent rehabilitative measure in transtibial amputations.

Robotic Resistance Treadmill Training Improves Locomotor Function in Human Spinal Cord Injury: A Pilot Study

Wu M, Landry JM, Schmit BD, Hornby TG, Yen S-C. Robotic resistance treadmill training improves locomotor function in human spinal cord injury: a pilot study. ObjectiveTo determine whether cable-driven robotic resistance treadmill training can improve locomotor function in humans with incomplete spinal cord injury (SCI). DesignRepeated assessment of the same patients with crossover design. SettingResearch units of rehabilitation hospitals in Chicago. ParticipantsPatients with chronic incomplete SCI (N=10) were recruited to participate in this study. InterventionsSubjects were randomly assigned to 1 of 2 groups. One group received 4 weeks of assistance training followed by 4 weeks of resistance training, while the other group received 4 weeks of resistance training followed by 4 weeks of assistance training. Locomotor training was provided by using a cable-driven robotic locomotor training system, which is highly backdrivable and compliant, allowing patients the freedom to voluntarily move their legs in a natural gait pattern during body weight supported treadmill training (BWSTT), while providing controlled assistance/resistance forces to the leg during the swing phase of gait. Main Outcome MeasuresPrimary outcome measures were evaluated for each participant before training and after 4 and 8 weeks of training. Primary measures were self-selected and fast overground walking velocity and 6-minute walking distance. Secondary measures included clinical assessments of balance, muscle tone, and strength. ResultsA significant improvement in walking speed and balance in humans with SCI was observed after robotic treadmill training using the cable-driven robotic locomotor trainer. There was no significant difference in walking functional gains after resistance versus assistance training, although resistance training was more effective for higher functioning patients. ConclusionsCable-driven robotic resistance training may be used as an adjunct to BWSTT for improving overground walking function in humans with incomplete SCI, particularly for those patients with relatively high function.

Comparative Effect of Orthosis Design on Functional Performance

High-energy extremity trauma is common in combat. Orthotic options for patients whose lower extremities have been salvaged are limited. A custom energy-storing ankle-foot orthosis, the Intrepid Dynamic Exoskeletal Orthosis (IDEO), was created and used with high-intensity rehabilitation as part of the Return to Run clinical pathway. We hypothesized that the IDEO would improve functional performance compared with a non-custom carbon fiber orthosis (BlueRocker), a posterior leaf spring orthosis, and no brace. Eighteen subjects with unilateral dorsiflexion and/or plantar flexion weakness were evaluated with six functional tests while they were wearing the IDEO, BlueRocker, posterior leaf spring, or no brace. The brace order was randomized, and five trials were completed for each of the functional measures, which included a four-square step test, a sit-to-stand five times test, tests of self-selected walking velocity over level and rocky terrain, and a timed stair ascent. They also completed one trial of a forty-yard (37-m) dash, filled out a satisfaction questionnaire, and indicated whether they had ever considered an amputation and, if so, whether they still intended to proceed with it. Performance was significantly better with the IDEO with respect to all functional measures compared with all other bracing conditions (p < 0.004), with the exception of the sit-to-stand five times test, in which there was a significant improvement only as compared with the BlueRocker (p = 0.014). The forty-yard dash improved by approximately 35% over the values for the posterior leaf spring and no-brace conditions, and by 28% over the BlueRocker. The BlueRocker demonstrated a significant improvement in the forty-yard dash compared with no brace (p = 0.033), and a significant improvement in self-selected walking velocity on level terrain compared with no brace and the posterior leaf spring orthosis (p < 0.028). However, no significant difference was found among the posterior leaf spring, BlueRocker, and no-brace conditions with respect to any other functional measure. Thirteen patients initially considered amputation, but after completion of the clinical pathway, eight desired limb salvage, two were undecided, and three still desired amputation. Use of the IDEO significantly improves performance on validated tests of agility, power, and speed. The majority of subjects initially considering amputation favored limb salvage after this noninvasive intervention.