Development of a Detachable Body Weight Support Robotic Rollator with Wearable Sensors to Assist Overground Gait Rehabilitation

Overground gait training under body weight support (BWS) for patients who suffer from neurological injuries has been proven practical in recovering from walking ability. Conventionally, skilled therapists or additional robots are required to assist the patient’s body weight and pelvis movement, making the rehabilitation process physically and economically burdensome. We investigate if a BWS walker using only two actuators can support the user’s body weight and simultaneously protect/assist the transverse pelvis rotation, improving natural gait with minimal motion compensation. In this paper, a BWS strategy called transverse pelvis rotation support (TPRS) is proposed to enable the BWS system to generate cable tension in the forward direction, as a purpose to support transverse pelvis rotation in addition to our previously proposed static or variable BWS. Wearable sensory devices, including instrumented shoes and harness, were developed to provide real-time ground reaction force and pelvis rotation signals simultaneously. Ten non-disabled participants were unloaded with 0% ~ 15% BWS under four different controls. Vertical ground reaction force, transverse pelvis kinematics, and user experience were compared using proposed controls. One-Way repeated measures ANOVA analysis assessed if control strategies generally affect the performance. All proposed controls enable the walker to support part of the user’s body weight. SBWS-TPRS and VBWS-TPRS control enable users to achieve a significantly improved pelvic motion and prolonged single support phase than pure static BWS or variable BWS, although users perceive a higher workload under them. The proposed BWS controls show the potential to become a complementary method in gait rehabilitation.

Previously, no research has investigated differences in preferred gait characteristics during forwards and backwards running at varying body weight (BW) support. PURPOSE: To understand how BW support and direction of locomotion influence descriptors of preferred gait. METHODS: Subjects (n=8; 27.0±11.7 years, 173.8±3.5 cm, 74.0±8.7 kg) performed forward and backward running on a lower body positive pressure treadmill at different levels of BW support (i.e., 0%-80% body weight support). Subjects preferred running speed (PS), preferred stride frequency (PSF), and rate of perceived exertion (RPE) were measured. PS, PSF, and RPE were analyzed using a 2(exercise mode: forward and backward locomotion) x 5(BW support: 0%, 20%, 40%, 60%, and 80%) repeated measures analysis of variance (α= 0.05). RESULTS: PS, PSF, and RPE were not influenced by the interaction of exercise mode and BW support (p > 0.05). PS was different between modes (p < 0.001) and between BW support conditions (p < 0.01). For example, PS increased approximately 3.8%-8.5% and 3.0%-11.9% with decreasing BW support for forward and backward running, respectively. Additionally, PS during forward running was higher than that of backward running at reduced BW support (e.g., 3.4±.9 m/s and 2.5±.5 m/s for forward and backward running at 80% BW support, respectively). Furthermore, PSF (p< 0.001) and RPE (p< 0.01) were different between BW conditions but not different between direction of locomotion (p>0.05). Specifically, PSF (e.g., a decrease of 13.2% during forward running at 0% BW support vs. 80% BW support) and RPE (e.g., a decrease of 19.9% during forward running at 0% BW support vs. 80% BW support) during forward and backward running decreased with decreasing BW support. CONCLUSION: It seems that BW support may have more of an influence on preferred gait characteristics than direction of locomotion since PSF and RPE were not different between directions of locomotion.

Locomotion gait training system plays a significant role in therapy for the patients who are in recovering from hemiplegia, paraplegia, spinal cord injury or after stroke. Modern gait training systems commonly use a Body Weight Support (BWS) system which is to enable the spinal cord injury or stroke patients bearing their weight during the walking practice. The conventional rope-pulley mechanism in conventional BWS systems could cause the “pendulum effect” during gait training and make subject be uncomfortable. Furthermore, using only one rope-pulley mechanism the conventional BWS system could not flexibly modulate the supported force, for example, the hemiplegic patient. This research is aimed to develop a novel BWS system which will be used to support the spinal cord injury patient during gait training. The novel BWS system will be applied Pneumatic Artificial Muscles (PAM) for generating the support force. The mechanical structure of the new BWS system is totally different from the conventional body weight support system. Therefore, the new BWS system will have several advantages, such as simplicity, low cost and flexibly adjusting the unloading force. The purpose is to develop a very simple BWS system for gait training, however, its capabilities generating active unloading forces. An experiment with a perturbation was conducted using the new BWS system and a representative conventional BWS system (Counter Weight system) to verify the performance of the new BWS system and to investigate the gait variance of the subject under both two BWS system. The results showed that the new BWS system presented a better performance in comparison with the Counter Weight system.

The body weight support (BWS) system that allows a patient to support his or her body weight in step-wise fashion, depending on their physical condition, is an important intervention that assists individuals with gait disabilities in their gait rehabilitation. In this paper, we measured human body signals in order to verify a rehabilitation system using active harness that we developed for gait and balance training based on ceiling-rail platform. 20 healthy participants were performed to conduct daily activities related to lower limbs. They did a kind of motions related to daily life (Normal Walking, Stand-to-Sit, and Stair Walking Down) according to variation of body weight support rates (0%, 30%, 50% of subject’s body weight). The effectiveness of the weight supporting on healthy people is analyzed by the muscular activities and foot pressure distribution. In normal walking, the decrease of fore-foot pressure, lateral soleus muscle and biceps femoris muscle were remarkable. The result of stand-to-sit results motion indicated that the rearfoot pressure and tibialis anterior muscle activities exceptionally decreased according to body weight support. The stair walking down results indicate the marked drop of fore-foot pressure and rectus femoris muscle activities. Based on these results, a function of weight supporting is very helpful to improve the gait ability of people with gait disorder.

Partial body weight support during gait training and other tasks is a common practice. Approaches using robotic devices allow for a wide range of functions but at great cost and complexity. Based on constant force springs, we have created a low-cost body weight support system from off-the-shelf parts, with no tools required for assembly or maintenance, and it is easily integrated into any overhead support system. The design is presented as open source for future improvements. We evaluated the hysteresis using two different types of constant force springs, comprising clinically relevant levels of weight support, 61.2 N and 131 N. Force constancy during walking was examined. Hysteresis had noticeable effects on weight support, illustrating a potential challenge for future designs with body weight support through constant force springs. By providing the constant weight support, the most common type of body weight support, this device represents an accessible alternative to robotic dynamic body weight support tools.

Introduction Partial body weight support (BWS) systems have been employed for gait training of children with cerebral palsy (CP). Therefore, it would be important to analyze if the type of walking surface and the amount of body weight unloading over lower limbs change the way these children walk. Objectives Investigate the influence of walking surface and amount of body weight unloading on the spatial temporal characteristics during walking of children with CP. Materials and methods Seven children with spastic CP between four and eight years old and GMFCS (Gross Motor Function Classification System) between I and IV, were videotaped walking with 0%, 15% and 30% of BWS on both dynamic (treadmill) and static (ground level) surfaces. Walking spatial temporal variables were calculated. Results Children walked with similar velocity in all experimental conditions. While stance duration decreased as the percentage of BWS increased, no differences were found for stance and swing periods and cadence. Children walked with longer steps and strides and with faster strides on static surface compared to dynamic surface. Conclusion Children with CP presenting different levels of motor impairment presented some alterations in the spatial temporal walking parameters as they walked with body unloading. However, such alterations might be due mainly to the type of walking surface than the percentage of body weight unloading on lower limbs.

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.

Introduction: The locomotor training with body weight support has been proposed as an alternative for the rehabilitation of people with spinal cord injury, in order to develop most of the residual potential of the body. Objective: To compare the levels of muscle activation of the main muscle involved in gait during body weight-supported treadmill training and body weight-supported overground training in incomplete spinal cord injured patients. Methods: It was a prospective cross-sectional study, in which 11 incomplete injured patients were submitted to two modalities of gait with body weight support, the first one on the treadmill (two different speeds: 1 and 4km/h), and the second one with the walker on fixed floor. The electromyographical acquisition was done in the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL) and gluteus maximus (GM). Results: There was a greater muscle activation of all muscles analyzed in the treadmill training as compared to the over groundtraining, both at 4 km/h (RF: p=0.00), (VM: p=0.00), (VL: p=0.00) e (GM: p=0.00) and at 1km/h (RF: p=0.00), (VM: p=0.00), (VL: p=0.00) e (GM: p=0.00). When comparing the two modalities of treadmill training, at 4 and 1km/h, there was no statically significant difference between them (RF: p=0.36), (VM: p=1.00), (VL: p=1.00) e (GM: p=0.16). Conclusion: The gait training with body weight support is more effective in activating the muscles involved in the gait training on treadmill compared to overground training in patients with incomplete spinal cord injury.

BackgroundIt is not yet established if the use of body weight support (BWS) systems for gait training is effective per se or if it is the combination of BWS and treadmill that improves the locomotion of individuals with gait impairment. This study investigated the effects of gait training on ground level with partial BWS in individuals with stroke during overground walking with no BWS.MethodsTwelve individuals with chronic stroke (53.17 ± 7.52 years old) participated of a gait training program with BWS during overground walking, and were evaluated before and after the gait training period. In both evaluations, individuals were videotaped walking at a self-selected comfortable speed with no BWS. Measurements were obtained for mean walking speed, step length, stride length and speed, toe-clearance, durations of total double stance and single-limb support, and minimum and maximum foot, shank, thigh, and trunk segmental angles.ResultsAfter gait training, individuals walked faster, with symmetrical steps, longer and faster strides, and increased toe-clearance. Also, they displayed increased rotation of foot, shank, thigh, and trunk segmental angles on both sides of the body. However, the duration of single-limb support remained asymmetrical between each side of the body after gait training.ConclusionsGait training individuals with chronic stroke with BWS during overground walking improved walking in terms of temporal-spatial parameters and segmental angles. This training strategy might be adopted as a safe, specific and promising strategy for gait rehabilitation after stroke.

This study aimed to assess the effectiveness of gait training using body weight support on a treadmill compared with conventional gait training for people with subacute stroke who were unable to walk. This was a single-blind, randomized, controlled trial with a 6-month follow-up. Ninety-seven subjects were recruited within 6 weeks of stroke onset and were randomly assigned to conventional rehabilitative treatment plus gait training with body weight support on a treadmill (experimental group; n=52) and conventional treatment with overground gait training only (control group; n=45). All subjects were treated in 60-minute sessions every weekday for 4 weeks. Outcome measures were Motricity Index, Trunk Control test, Barthel Index, Functional Ambulation Categories, 10-meter and 6-minute Walk Tests, and Walking Handicap Scale. Assessments were made at baseline, after 20 sessions of treatment, 2 weeks after treatment, and 6 months after stroke. After treatment, all patients were able to walk. Both groups showed improvement in all outcome measures (P<0.0063) at the end of the treatment and at follow-up. No differences were seen between the 2 groups before, during, and after treatment and at follow-up. In subacute patients with stroke, gait training on a treadmill with body weight support is feasible and as effective as conventional gait training. However, the need for more personnel for treadmill training makes the use of robotically assisted systems more compelling.

A new gait training strategy for patients with stroke proposes to support a percentage of the patient's body weight while retraining gait on a treadmill. This research project intended to compare the effects of gait training with body weight support (BWS) and with no body weight support (no-BWS) on clinical outcome measures for patients with stroke. One hundred subjects with stroke were randomized to receive one of two treatments while walking on a treadmill: 50 subjects were trained to walk with up to 40% of their body weight supported by a BWS system with overhead harness (BWS group), and the other 50 subjects were trained to walk bearing full weight on their lower extremities (no-BWS group). Treatment outcomes were assessed on the basis of functional balance, motor recovery, overground walking speed, and overground walking endurance. After a 6-week training period, the BWS group scored significantly higher than the no-BWS group for functional balance (P = 0.001), motor recovery (P = 0.001), overground walking speed (P = 0.029), and overground w alking endurance (P = 0.018). The follow-up evaluation, 3 months after training, revealed that the BWS group continues to have significantly higher scores for overground walking speed (P = 0.006) and motor recovery (P = 0.039). Retraining gait in patients with stroke while a percentage of their body weight was supported resulted in better walking abilities than gait training while the patients were bearing their full weight. This novel gait training strategy provides a dynamic and integrative approach for the treatment of gait dysfunction after stroke.

Background & Purpose: To date, it is unclear whether robotic-assisted gait training is effective at restoring walking ability in hemiparetic stroke subjects. This case study provides an example of when a robotic gait-orthosis provides distinct advantages over conventional over-ground gait training strategies focused on gait restoration. Case Description: In February 2006 a 48 year old caucasian female presented with right quadrant pain, headaches, blurry vision and weakness in all four extremities. She was diagnosed with cortical blindness, bilateral occipital/parietal infarcts right greater than left secondary to necrotizing vasculitis. Upon transfer to the National Rehabilitation Hospital in March 2006, patient presented with impairments in multi-systems resulting in poor posture and motor control, increased extensor tone, decreased body awareness, localized hypersensitivity to touch, decreased skin integrity, decreased perceptual skills, decreased recent memory and hypothetical problem solving. During the first month the treatment focused on stability in sitting and increasing body awareness. Treatment progressed to learning how to initiate gross motor movement with breathing strategies. Visual training was incorporated into every session initially to track objects with her eyes with stationary head then with head turning. She advanced to localizing and reaching for objects. During the next four weeks standing activities and gait were the focus. Attempts at gait training were not successful as patient could not initiate stepping. An over ground body-weight support system was trialed for two weeks. Though able to take steps with body weight support, there was no carry over to functional walking when unweighted. Finally the patient was trialed on the Lokomat (Hocoma AG, Volketswil, Switzerland) a robotic-gait orthosis suspended over a treadmill. The patient was trained three times a week on the Lokomat for 5 sessions progressing from approximately 50% to 20% body weight, walking duration from 9 minutes to 30 minutes at 1.5 Km/hr to 2.0 Km/hr. Outcomes: Over the first two months of therapy the patient showed slow yet steady improvements in functional mobility skills, increase in sitting control and static standing control. Her ability to take steps only occurred with body-weight support. She was not able to transfer those movements to walking without body-weight support in the parallel bars. However, after the patient trained in the Lokomat, within two sessions, she was able to take steps in the parallel bars without body-weight support. Discussion: The use of a robotic-gait orthosis may offer advantages over conventional approaches for improving walking ability, particularly in individuals with multiple sensorimotor impairments. Devices such as the Lokomat can help initiate and maintain stepping patterns, which when combined with body-weight support, provides unique therapeutic advantages.

IntroductionBody weight support overground walking training (BWSOWT) is widely used in gait rehabilitation. However, existing systems require large workspace, complex structure, and substantial installation cost for the actuator, which make those systems inappropriate for the clinical environment. For wide clinical use, the proposed system is based on a self-paced treadmill, and uses an optimized body weight support with frame-based two-wire mechanism.MethodThe Interactive treadmill was used to mimic overground walking. We opted the conventional DC motors to partially unload the body weight and modified pelvic type harness to allow natural pelvic motion. The performance of the proposed system on the measurement of anterior/posterior position, force control, and pelvic motion was evaluated with 8 healthy subjects during walking training.ResultsWe verified that the proposed system was the cost/space-effective and showed the more accurate anterior/posterior position than motion sensor, comparable force control performance, and natural pelvic motion.DiscussionThe proposed system is cost/space effective, and able to mimic overground walking training with body weight support. In future work, we will improve the force control performance and optimize the training protocol for wide clinical use.

BackgroundPatients undergoing total knee arthroplasty (TKA) may benefit from early focused postoperative rehabilitation, and progressive weight-bearing activities, such as walking, are routinely recommended during rehabilitation to facilitate return to normal...

Functional gait training in cerebral palsy can involve over ground gait training or treadmill-based gait training which incorporates partial body weight support (PBWS) system. Insufficient clinical evidence prevails to recommend the superiority over the other intervention. ICF model has created a paradigm shift in understanding motor learning mechanisms, with the use of repetitive, task-specific movements beneficial to restructuring motor pathways. The primary aim of the study was to compare the effect of integrated task oriented Body Weight Supported overground Training (BWSOGT) against the Body Weight Supported Treadmill Training (BWSTT) and the conventional gait training protocols to improve the functional mobility in Cerebral Palsy. Methods: A Single-blinded, randomised control design. Sixty-children with GMFCS Level of III, IV were recruited in the study with an age ranges between 4 to 14 years (mean age = 9). Participants were randomly assigned into three groups using simple randomisation method with 20 subjects in each group for 8 weeks. The training programme consists of Group A with 40% of body weight supported walker with overhead pulley system which allows multiple degrees of freedom. Body weight- supported treadmill training (Group B) in a closed environment and conventional gait protocol using standard walkers (Group C). Outcome measures: Gross Motor Function Measure dimension-88 (GMFM-88) score. Gait kinematics (Stride length, Step length, Cadence) and 10 meter walk test. Tukey’s Post Hoc for group and time interactions, Krushkal Wallis test for overall significance and Mann Whitney’s U test to compare the significance between the groups. BWSOGT group showed significance over the BWSTT and Control group in GMFM score with p = 0.000 p = 0.002, respectively. Step length of gait parameter remained unchanged in all the three groups. Integrated task oriented BWSOGT might be an effective intervention to improve functional ambulation in children with spastic cerebral palsy due to the usage of a context specific environment and the training protocol.