Effect Of Body Weight Support Research Articles

The Effect of Bodyweight Support and Incline Running on Triceps Surae Electromyographic Activity

Body weight support (BWS) and incline running (IR) are commonly used either during rehabilitation or during training separately, with many positive effects on athletes’ performance and rehabilitation. The aim of the present study was to investigate the interaction between bodyweight support and incline running on the electromyographic activity of the triceps surae and compare it to flat running. In eighteen healthy men (age: 20.3 ± 1.2 years, body weight: 70.2 ± 4.8 kg, body height: 179.6 ± 5.4 cm), the changes in electromyographic activity (EMGA) during a 10 min run with BWS (15% or 30% of body weight; in different occasions) and IR at 7%, as well as jumping performance and gait spatiotemporal parameters, were evaluated. A lower Rating of Perceived Exertion and a significant decrease in the size of the Vastus Lateralis (VL) (33.4%), Soleus (SOL) (17%), and Gastrocnemius Lateralis (GL) EMGA (28.5%, p < 0.05) but not in Gastrocnemius Medialis (GM) (10.5%, p > 0.05), was observed during BWS30% at 7% slope compared to flat running. Also, low-frequency fatigue of the quadriceps was induced only after running without BWS on a 7% slope (p = 0.011). No changes were found in jumping performance (p = 0.246) and gait spatiotemporal parameters (p > 0.05) except for flight time (p < 0.006). In conclusion, running with a slope of 7% and 30% of BWS can result in EMG activity comparable to that observed during level running. This method can also be used in prevention and rehabilitation training programs without creating fatigue.

Effects of Body Weight Support in Running on Achilles Tendon Loading.

Achilles tendon (AT) tendinopathy is common in runners. Repetitive AT loading may play a role in etiology. Interventions such as body weight support (BWS) may reduce loading on the AT in running. Examine how ground reaction force, AT loading, foot strike and cadence variables change in running with BWS. Twenty-four healthy female runners free from injury were examined. Participants ran on an instrumented treadmill with and without BWS using a harness-based system at a standardized speed. The system has 4 elastic cords affixed to a harness that is attached to a frame-like structure. Kinematic data and kinetic data were used in a musculoskeletal model (18 segments and 16 degrees of freedom) to determine AT loading variables, foot strike angle and cadence. Paired t-tests were used to compare each variable between conditions. Ground reaction force was 9.0% lower with BWS (p<.05). Peak AT stress, force, and impulse were 9.4%, 11.7% and 14.8% lower when using BWS in running compared to no support (p<.05). Foot strike angle was similar (p<.05) despite cadence being reduced (p<.05). BWS may reduce AT loading and impulse variables during running. This may be important in the rehabilitation efforts.

Effect of bodyweight support and incline running on electromyographic activity of triceps surae

During rehabilitation, body weight support (BWS) system is often used. It can be useful for optimizing time to return to practice by unloading joints and muscles. The present study aimed to explore the effects of Body Weight Support (BWS) and Incline Running (IR) on electromyographic activity (EMG) of triceps surae. We hypothesized that running with a slope of 7% and 30% of BWS could result in EMG comparable to level running. Eighteen healthy individuals participated in four randomized experimental sessions of ten minutes run at 10 km/h: 1) level running and 0% of BWS (LR), 2) incline running at 7% and 0% of BWS, 3) incline running at 7% and 15% of BWS, 4) incline running at 7% and 30% of BWS. EMG activity of Vastus Lateralis (VL), Gastrocnemius Lateralis (GL), Gastrocnemius Medialis (GM), and Soleus (SOL) was recorded during each 10 minutes running conditions and before two times during 30 seconds level running to normalize EMG activity (baseline). In addition, gait spatiotemporal parameters were taken at 1’, 5’ and 9 minutes and Rating of Perceived Exertion RPE was asked at 5’, 7’, and 10 minutes. Tests were conducted before and two minutes after running conditions. They included Counter Movement Jump (CMJ), and quadriceps low-frequency fatigue test.The results of the present study revealed a significant decrease in electromyographic activity of SOL at IR at 30% of BWS condition compared to IR without BWS (P &lt; 0.002). Moreover, a significant decrease in electromyographic activity was observed of VL at IR at 30% of BWS condition compared to level running and IR conditions without BWS (P &lt; 0.002 and P &lt; 0.001). No changes were found in jump test (P = 0.246) and gait spatiotemporal parameters (P &gt; 0.05) except in flight time (decrease with IR, increase with BWS, P &lt; 0.006). Rate of Perceived Exertion was decreased with 30% of BWS (P &lt; 0.002) and was no different to level running (P = 0.079). 15% of BWS (vs. uphill without BWS) did not significantly decrease the difficulty perception (P = 0.570). Also, low-frequency fatigue of the quadriceps was induced without BWS (P = 0.011) but not with 15% and 30% BWS (P &gt; 0.05)Our results show that EMG activity of the triceps surae can be similar between running on a flat surface and running on a slope and 30% BWS. Furthermore, muscle fatigue, perceived exertion rate and spatio-temporal running parameters were similar between running on a flat surface and 30% BWS at 7% IR. Therefore, it can be useful to optimize the return time to practice and it is recommending for monitoring loads in Achilles Tendon and triceps surae. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effects of body weight support and guidance force settings on muscle synergy during Lokomat walking.

The Lokomat is a robotic device that has been suggested to make gait therapy easier, more comfortable, and more efficient. In this study, we asked whether the Lokomat promotes physiological muscle activation patterns, a fundamental question when considering motor learning and adaptation. We investigated lower limb muscles coordination in terms of muscle activity level, muscle activity pattern similarity, and muscle synergy in 15 healthy participants walking at 3km/h on either a treadmill or in a Lokomat at various guidance forces (GF: 30, 50 or 70%) and body weight supports (BWS: 30, 50 or 70% of participant's body weight). Walking in the Lokomat was associated with a greater activation level of the rectus femoris and vastus medialis (×2-3) compared to treadmill walking. The level of activity tended to be diminished in gastrocnemius and semi-tendinosus, which particularly affected the similarity with treadmill walking (normalized scalar product NSP = 0.7-0.8). GF and BWS independently altered the muscle activation pattern in terms of amplitude and shape. Increasing BWS decreased the level of activity in all but one muscle (the soleus). Increasing GF slightly improved the similarity with treadmill walking for the tibialis anterior and vastus medialis muscles. The muscle synergies (N = 4) were similar (NSP = 0.93-0.97), but a cross-validation procedure revealed an alteration by the Lokomat. The activation of these synergies differed (NSP = 0.74-0.82). The effects of GF and BWS are modest compared to the effect of the Lokomat itself, suggesting that Lokomat design should be improved to promote more typical muscle activity patterns.

Effects of body weight support and gait velocity via antigravity treadmill on cardiovascular responses early after total knee arthroplasty.

To investigate the effects of body weight support (BWS) and gait velocity on cardiovascular responses during walking on an antigravity treadmill early after unilateral and bilateral total knee arthroplasty (TKA).This study was a cross-sectional study design. Fifty patients (7 males and 43 females; average age, 72.0 ± 5.1 years) at 4 weeks after unilateral (n = 25) and bilateral (n = 25) primary TKA were enrolled in the study. Subjects walked on an antigravity treadmill at speeds of 2.5 km/hour and 3.5 km/hour with 3 levels (50%, 25%, and 0%) of BWS. Cardiovascular responses were monitored by measuring oxygen consumption (VO2), heart rate (HR), systolic and diastolic blood pressure (SBP/DBP), the respiratory exchange ratio (RER), and rate pressure product (RPP). Borg rating of perceived exertion (RPE) and a visual analog scale (VAS) of knee pain were recorded immediately after each trial.There were no significant differences in cardiovascular responses between the unilateral and bilateral TKA groups. In the repeated measures Analysis of Variance, VO2 levels, HR, RPP, RPE, RER, and VAS were significantly increased in proportion to 3 levels (50%, 25%, and 0%) of BWS for unilateral and bilateral TKA groups, respectively. Meanwhile, SBP and DBP were unaffected by differences in BWS. At 3.5 km/hour, VO2, RPE, and RER values were statistically greater than those at 2.5 km/hour under the same BWS conditions.We found that the reduction in the metabolic demand of activity, coupled with positive pressure on the lower extremities, reduced VO2 and HR values as BWS increased.Cardiovascular responses vary according to BWS and gait velocity during antigravity treadmill walking. BWS rather than gait velocity had the greatest effect on cardiovascular responses and knee pain.

Effects of bodyweight support and guidance force on muscle activation during Locomat walking in people with stroke: a cross-sectional study

BackgroundLocomat is a robotic exoskeleton providing guidance force and bodyweight support to facilitate intensive walking training for people with stroke. Although the Locomat has been reported to be effective in improving walking performance, the effects of training parameters on the neuromuscular control remain unclear. This study aimed to compare the muscle activities between Locomat walking and treadmill walking at a normal speed, as well as to investigate the effects of varying bodyweight support and guidance force on muscle activation patterns during Locomat walking in people with stroke.MethodsA cross-sectional study design was employed. Participants first performed an unrestrained walking on a treadmill and then walked in the Locomat with different levels of bodyweight support (30% or 50%) and guidance force (40% or 70%) at the same speed (1.2 m/s). Surface electromyography (sEMG) of seven muscles of the affected leg was recorded. The sEMG envelope was time-normalised and averaged over gait cycles. Mean sEMG amplitude was then calculated by normalising the sEMG amplitude with respect to the peak amplitude during treadmill walking for statistical analysis. A series of Non-parametric test and post hoc analysis were performed with a significance level of 0.05.ResultsFourteen participants with stroke were recruited at the Yangzhi Affiliated Rehabilitation Hospital of Tongji University (female n = 1; mean age 46.1 ± 11.1 years). Only the mean sEMG amplitude of vastus medialis oblique during Locomat walking (50% bodyweight support and 70% guidance force) was significantly lower than that during treadmill walking. Reducing both bodyweight and guidance increased muscle activity of gluteus medius and tibialis anterior. Activity of vastus medialis oblique muscle increased as bodyweight support reduced, while that of rectus femoris increased as guidance force decreased.ConclusionsThe effects of Locomat on reducing muscle activity in people with stroke were minimized when walking at a normal speed. Reducing bodyweight support and guidance force increased the activity of specific muscles during Locomat walking. Effects of bodyweight support, guidance force and speed should be taken into account when developing individualized Locomat training protocols for clients with stroke.

Effects of body weight support and pedal stance width on joint loading during pinnacle trainer exercise

BackgroundA pinnacle trainer is a stair climber that has a biplane exercise trajectory and an adjustable pedal stance width (PSW). A pinnacle trainer integrated with a body weight support (BWS) system can help overweight individuals or individuals with poor balance exercise safely by reducing excessive or improper joint loads, preventing training-related injuries. However, few studies have investigated the biomechanical features of the lower extremities during pinnacle trainer exercise with and without partial BWS for various PSWs. Research questionWe aimed to investigate the effects of partial BWS and PSW on the joint loading of the lower extremities during stepping on a pinnacle trainer. MethodsSeventeen healthy adults exercised on the pinnacle trainer with or without BWS using various PSWs. The joint resultant forces and joint moments of the lower extremities were calculated according to the kinematic and kinetic data measured via a motion capture system and force transducers on the pedals, respectively. ResultsThe joint resultant forces and joint moments of the lower extremities significantly decreased with increasing percentage of BWS. The internal knee adduction moment and internal hip abduction moment significantly increased with increasing PSW. For every kilogram of BWS, the joint loading of the lower extremities decreased by approximately 1% of the joint resultant forces of body weight during exercise with the pinnacle trainer. SignificanceExercise on the pinnacle trainer with partial BWS significantly reduced joint loading. Exercise with a wider pedal stance may be helpful for knee osteoarthritis rehabilitation as it produces greater internal hip abduction and internal knee adduction moments.

Effect of body weight support on muscle activation during walking on a lower body positive pressure treadmill

Following lower limb injury, some patients are not able to walk at full weight bearing and may require body weight support for ambulation during the early stages of rehabilitation. The aim of the present study was to investigate how various degrees of reduced effective body weight in a Lower Body Positive Pressure Treadmill (LBPPT), affects muscle activation levels during walking. Twelve healthy participants were instructed to walk at 2.5 km/h and 3.6 km/h on a LBPPT that provided a reduced effective body weight equivalent to 100%, 80%, 60%, 40%, and 20% of their individual body mass. Electromyography data were recorded during 20 gait cycles, from seven lower limb muscles, and segmented into a mean envelope by computing root mean square values. A two-way repeated measures ANOVA was used to test for differences in the highest root mean square value obtained, with walking speed and fractional reduction in effective body weight as factors. Significant decreases in EMG amplitude were identified in the following muscles as a result of reduced effective body weight: Vastus Medialis, Vastus Lateralis, Soleus, Gastrocnemius Medial and Lateral head (p ≤ 0.05). For Tibialis Anterior, significant reductions in EMG amplitude were only observed when effective body weight was reduced to 40% or less at a walking speed of 2.5 km/h (p ≤ 0.05). The EMG amplitude for Tibialis Anterior at 3.6 km/h and Biceps Femoris at both speeds remained unaffected at all fractional reductions (p ≥ 0.05). These findings suggests that the muscles of the lower limb respond differently to the body weight support provided by the LBPPT during walking, with the extensor muscles of the knee and ankle displaying decreased muscle activation, and the Tibialis Anterior and Biceps Femoris displaying minimal to no changes in muscle activation.

Effect of body weight support on predicted locomotive physical activity.

[Purpose] This study aimed to evaluate the effect of body weight support with an assistive device on predicted locomotive physical activity measured using triaxial accelerometers in healthy young subjects. [Subjects and Methods] Sixteen healthy subjects aged 21.9 ± 1.1 years walked on a treadmill at speeds of 45 and 55 meters/min under 0%, 10%, 20%, and 30% body weight support conditions. Predicted metabolic equivalents and number of steps were evaluated using triaxial accelerometers. Measured metabolic equivalents and number of steps were evaluated using a metabolic system and observers, respectively. Raw data of synthetic accelerations were also obtained. [Results] Predicted metabolic equivalents and number of steps and raw data of synthetic accelerations decreased with increasing amounts of body weight support. [Conclusion] These findings suggest that accelerometers may underestimate locomotive physical activity with increasing amounts of body weight support using assistive devices. Thus, it is important to consider the amount of body weight support when assessing physical activities in subjects using assistive devices for mobility.

Biomechanical effects of body weight support with a novel robotic walker for over-ground gait rehabilitation.

Body weight support (BWS) promotes better functional outcomes for neurologically challenged patients. Despite the established effectiveness of BWS in gait rehabilitation, the findings on biomechanical effects of BWS training still remain contradictory. Therefore, the aim of this study is to comprehensively investigate the effects of BWS. Using a newly developed robotic walker which can facilitate pelvic motions with an active BWS unit, we compared gait parameters of ten healthy subjects during a 10-m walk with incremental levels of body weight unloading, ranging from 0 to 40% at 10% intervals. Significant changes in joint angles and gait temporospatial parameters were observed. In addition, the results of an EMG signal study showed that the intensity of muscle activation was significantly reduced with increasing BWS levels. The reduction was found at the ankle, knee, and hip joints in the sagittal plane as well as at the hip joint in the frontal plane. The results of this study provide an important indication of increased lateral body balance and greater stabilization in sagittal and frontal plane during gait. Our findings provide a better understanding of the biomechanical effects of BWS during gait, which will help guide the gait rehabilitation strategies.

Dimensionality and Item-Difficulty Hierarchy of the Lower Extremity Fugl-Meyer Assessment in Individuals With Subacute and Chronic Stroke

ObjectiveTo investigate the dimensionality and item-difficulty hierarchy of the Fugl-Meyer Assessment of the lower extremity (FMA-LE). DesignSecondary analyses of data pooled from 4 existing datasets: a phase III randomized controlled trial investigating the effectiveness of body weight support and a treadmill for rehabilitation of walking poststroke, and 3 cross-sectional studies investigating the link between impaired motor performance poststroke and walking. SettingUniversity research centers and rehabilitation centers. ParticipantsA pooled sample of individuals with a stroke (N=535, men=313; mean age ± SD, 61.91±12.42y). InterventionsNot applicable. Main Outcome MeasuresConfirmatory factor analyses (CFA) and Rasch residual principal component analysis (PCA) investigated the dimensionality of the FMA-LE. The Rasch analysis rating scale model investigated item-difficulty hierarchy of the FMA-LE. ResultsThe CFA showed adequate fit of a 3-factor model, with 2 out of 3 indices (CFA=.95; Tucker-Lewis Index=.94; root mean square error of approximation=.124) showing good model fit. Rasch PCA showed that removal of the reflex and coordination items explained 90.8% of variance in the data, suggesting that the abnormal synergy items contributed to the measurement of a unidimensional construct. However, rating scale model results revealed deviations in the item-difficulty hierarchy of the unidimensional abnormal synergy items from the originally proposed stepwise sequence of motor recovery. ConclusionsOur findings suggest that the FMA-LE might represent a multidimensional construct, challenging the use of a total score of the FMA-LE to predict lower extremity motor recovery. Removal of the misfit items resulted in creation of a unidimensional scale composed of the abnormal synergy items. However, this unidimensional scale deviates from the originally proposed hierarchical ordering.

The Effect of Body Weight Support on Kinetics and Kinematics of a Repetitive Plyometric Task.

Though essential to athletic performance, the ability to land from a jump often remains limited following injury. While recommended, jump training is difficult to include in rehabilitation programs due to high impact forces. Body weight support (BWS) is frequently used in rehabilitation of gait following neurological and orthopedic injury, and may also allow improved rehabilitation of high-impact tasks. There is a differential effect of BWS on walking and running gaits, and the effect of BWS on movements with relatively large vertical displacement is unknown. The current study evaluates the effect of BWS on a replicable single-leg hopping task. We posited that progressive BWS would decrease limb loading while maintaining the joint kinematics of the task. Twenty-eight participants repetitively hopped on and off a box at each of four BWS levels. Peak vertical ground reaction forces decreased by 22.5% between 0% and 30% BWS (P < .001). Average hip, knee, and ankle internal moments decreased by 0.5 N·m/kg each. Slight kinematic changes across BWS levels were clinically insignificant. The high level of task specificity evidenced by consistent kinematics coupled with a similar reduction of internal moment at each joint suggests that BWS may be a useful strategy for rehabilitation of jumping tasks.

The combined effects of body weight support and gait speed on gait related muscle activity: a comparison between walking in the Lokomat exoskeleton and regular treadmill walking.

BackgroundFor the development of specialized training protocols for robot assisted gait training, it is important to understand how the use of exoskeletons alters locomotor task demands, and how the nature and magnitude of these changes depend on training parameters. Therefore, the present study assessed the combined effects of gait speed and body weight support (BWS) on muscle activity, and compared these between treadmill walking and walking in the Lokomat exoskeleton.MethodsTen healthy participants walked on a treadmill and in the Lokomat, with varying levels of BWS (0% and 50% of the participants’ body weight) and gait speed (0.8, 1.8, and 2.8 km/h), while temporal step characteristics and muscle activity from Erector Spinae, Gluteus Medius, Vastus Lateralis, Biceps Femoris, Gastrocnemius Medialis, and Tibialis Anterior muscles were recorded.ResultsThe temporal structure of the stepping pattern was altered when participants walked in the Lokomat or when BWS was provided (i.e. the relative duration of the double support phase was reduced, and the single support phase prolonged), but these differences normalized as gait speed increased. Alternations in muscle activity were characterized by complex interactions between walking conditions and training parameters: Differences between treadmill walking and walking in the exoskeleton were most prominent at low gait speeds, and speed effects were attenuated when BWS was provided.ConclusionWalking in the Lokomat exoskeleton without movement guidance alters the temporal step regulation and the neuromuscular control of walking, although the nature and magnitude of these effects depend on complex interactions with gait speed and BWS. If normative neuromuscular control of gait is targeted during training, it is recommended that very low speeds and high levels of BWS should be avoided when possible.

Sprint Running With a Body-Weight Supporting Kite Reduces Ground Contact Time in Well-Trained Sprinters

It is well founded that ground contact time is the crucial part of sprinting because the available time window to apply force to the ground diminishes with growing running velocity. In view of this knowledge, the purpose of this study was to investigate the effects of body-weight support during full-effort sprints on ground contact time and selected stride parameters in 19 Austrian male elite sprinters. A kite with a lifting effect combined with a towing system to erase drag was used. The subjects performed flying 20-m sprints under 3 conditions: (a) free sprint; (b) body-weight supported sprint-normal speed (BWS-NS); and (c) body-weight supported sprint-overspeed (BWS-OS). Sprint cycle characteristics were recorded during the high-speed phase by an optical acquisition system. Additionally, running velocity was derived from the 20-m sprint time. Compared with the fastest free sprint, running velocity, step length, and step frequency remained unchanged during BWS-NS, whereas ground contact time decreased (-5.80%), and air time increased (+5.79%) (both p < 0.001). Throughout, BWS-OS ground contact time (-7.66%) was reduced, whereas running velocity (+2.72%), air time (+4.92%), step length (+1.98%) (all p < 0.001), and step frequency (+1.05%; p < 0.01) increased. Compared with BWS-NS, BWS-OS caused an increase in running velocity (+3.33%), step length (+1.92%) (both p < 0.001), and step frequency (+1.37%; p < 0.01), whereas ground contact time was diminished (-1.97%; p < 0.001). In summary, sprinting with a body-weight supporting kite appeared to be a highly specific method to simulate an advanced performance level, indicated by higher running velocities requiring reduced ground contact times. The additional application of an overspeed condition led to a further reduction of ground contact time. Therefore, we recommend body-weight supported sprinting as an additional tool in sprint training.

Aging and partial body weight support affects gait variability

BackgroundAging leads to increases in gait variability which may explain the large incidence of falls in the elderly. Body weight support training may be utilized to improve gait in the elderly and minimize falls. However, before initiating rehabilitation protocols, baseline studies are needed to identify the effect of body weight support on elderly gait variability. Our purpose was to determine the kinematic variability of the lower extremities in young and elderly healthy females at changing levels of body weight support during walking.MethodsTen young and ten elderly females walked on a treadmill for two minutes with a body weight support (BWS) system under four different conditions: 1 g, 0.9 g, 0.8 g, and 0.7 g. Three-dimensional kinematics was captured at 60 Hz with a Peak Performance high speed video system. Magnitude and structure of variability of the sagittal plane angular kinematics of the right lower extremity was analyzed using both linear (magnitude; standard deviations and coefficient of variations) and nonlinear (structure; Lyapunov exponents) measures. A two way mixed ANOVA was used to evaluate the effect of age and BWS on variability.ResultsLinear analysis showed that the elderly presented significantly more variability at the hip and knee joint than the young females. Moreover, higher levels of BWS presented increased variability at all joints as found in both the linear and nonlinear measures utilized.ConclusionIncreased levels of BWS increased lower extremity kinematic variability. If the intent of BWS training is to decrease variability in gait patterns, this did not occur based on our results. However, we did not perform a training study. Thus, it is possible that after several weeks of training and increased habituation, these initial increased variability values will decrease. This assumption needs to be addressed in future investigation with both "healthy" elderly and elderly fallers. In addition, it is possible that BWS training can have a positive transfer effect by bringing overground kinematic variability to healthy normative levels, which also needs to be explored in future studies.

Effect of body weight support and walking speed on intersegmental coordination during gait

Effect of body weight support and walking speed on intersegmental coordination during gait

Effect of body weight support on cortical activation during gait in patients with stroke

Treadmill training with body weight support (BWS) was shown to improve locomotion after stroke. We investigated whether BWS affected cortical activation during gait using an optical imaging system. In six patients with subcortical stroke, BWS lowered activation in the sensorimotor cortex (SMC) as assessed by task-related changes of oxygenated hemoglobin levels (P<0.01). The changes of SMC activation correlated with those of cadence (P<0.05). Improvement of asymmetry in SMC activation also correlated with improvement of asymmetric gait (P<0.05). In five age-matched controls, BWS increased overall activation (P<0.05) but did not modify gait parameters and there was no correlation between gait parameters and SMC activation. It is suggested that BWS might improve efficacy of SMC function in patients with stroke.

Treadmill Training with Partial Body Weight Support: Influence of Body Weight Release on the Gait of Hemiparetic Patients

Objective: To investigate the effect of body weight support on the gait of hemiparetic subjects walking on a treadmill. Design: Survey. Patients: Eleven nonambulatory hemi paretic subjects. Methods: Subjects walked on the treadmill with full weight bearing and with 15%, 30%, 45%, and 60% body weight support at constant walking veloc ity. Cycle parameters, symmetry ratios, and the kinematic EMG of several lower limb muscles of the affected leg were recorded. Video-analysis served for assessment of pos ture and hip and knee angle displacement. Results: With body weight support the rel ative double support time decreased, the relative single stance period of the affected limb increased, and the functional activity of the vastus and soleus diminished. The activity of the gluteus tended to increase. Patients walked more upright and with less hip and knee flexion. The extensor spasticity did not change and the qualitative acti vation pattern of all recorded muscles remained unchanged. Conclusion: Body weight su...

The effects of body weight support on the locomotor pattern of spastic paretic patients.

The effects of mechanically supporting a percentage of body weight on the gait pattern of spastic paretic subjects during treadmill locomotion was investigated. Electromyographic (EMG), joint angular displacement and temporal distance data were simultaneously recorded while 7 spastic paretic subjects walked at 0% and 40% body weight support (BWS) at their maximal comfortable treadmill speed. Forty percent BWS produced a general decrease in EMG mean burst amplitude for the lower limb muscles investigated with instances of more appropriate EMG timing in relation to the gait cycle. The joint angular displacement data at 40% BWS revealed straighter trunk and knee alignment during the weight bearing phase especially at initial foot-floor contact and midstance. An increase in single limb support time and a decrease in percentage total double support time were evident at 40% BWS. An increase in stride length and maximum comfortable walking speed was also seen with BWS. The use of BWS during treadmill locomotion as a therapeutic approach to retrain gait in neurologically impaired patients is discussed.