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In this paper we explore the mechanical behavior of the ankle in the progression stage of stance during normal walking. We show that the torque/angle behavior of the ankle during this stage can be approximated by an augmented linear torsional spring. The mechanical parameters completely specifying this spring are identified, including stiffness, amount of rotation, and angle of zero moment. The effect...
This paper investigates a quantization and clustering issue on human motion performance constrained by disabilities. In a longitudinal study of medical therapy on motion disorder, stages of patient disability condition change over time. We investigate four different stages of one arm constrained walking motions by restricting 0%, 10%, 16% and 22% of arm swing angles. For analysis we use One-way ANOVA...
While many studies have reported on the use of kinematic analysis on well-controlled, in-laboratory mobility tasks, few studies have examined the challenges of recording dynamic mobility in home environments. This preliminary study evaluated whole body mobility in eleven patients with Parkinson disease (H&Y 2–4). Patients were recorded in their home environment during scripted and non-scripted...
The purpose of this study is to develop a wireless FES rehabilitation system to assist effective improvement of the lower limbs. In this report, a prototype system combined with foot drop correction and gait evaluation using wireless surface electrical stimulator and the wireless inertial sensors was developed and tested with a right hemiplegic subject. For gait evaluation, lower limb joint angles...
This paper examines the impact of a biomimetic active knee prosthesis on the metabolic costs associated with a unilateral transfemoral amputee walking at self selected speed. In this study we compare the antagonistic active knee prosthesis developed at MIT to an electronically controlled, variable-damping commercial knee prosthesis, the Otto Bock C-leg. Use of the active knee prosthesis resulted in...
Human locomotion is based on the finely tuned coordination of the two legs. For this research, we studied the contribution of interlimb pathways for coordinating and synchronizing the legs' motion in the case where body weight is externally supported and vestibular feedback is limited. The experiments were conducted using a novel device intended for gait therapy: the MIT-Skywalker. The subject's body...
The objective of this study is to develop a 3D ankle-foot model containing toe expression for designing an AFO (ankle-foot orthosis) with a training function. Two experiments were conducted to (1) show the influence of toes by comparing walking with and without an AFO, and (2) clarify the functions of toes during walking by correlating the activity of the major muscles controlling the ankle and the...
Before 2009, the feasibility of applying brain-machine interfaces (BMIs) to control prosthetic devices had been limited to upper limb prosthetics such as the DARPA modular prosthetic limb. Until recently, it was believed that the control of bipedal locomotion involved central pattern generators with little supraspinal control. Analysis of cortical dynamics with electroencephalography (EEG) was also...
To explore the effect of LOKOMAT and LOKOMAT+Tizanidine on the improvement of walking capacity for people with spinal cord injury (SCI), 20 SCI subjects with hypertonia spasticity at their ankle joints participated in a 12-session Lokomat training; among them, 10 subjects received Tizanidine. 1-hour LOKOMAT training was provided 3 times per week for 4-weeks. Subjects were evaluated 4 times for Timed-Up-and-Go,...
In contrast to the muscle recruitment during voluntary walking, only a limited number of muscles are activated during functional electrical stimulation (FES)-based walking. This implies that a trajectory designed or recorded from the normal human walking data may not be the best choice for tracking control. Another major challenge during FES-based walking is the rapid onset of muscle fatigue. Two...
A mechanical Lower Limb Paralysis Simulator (LLPS) was developed for able-bodied persons to model the gait of Reciprocating Gait Orthosis (RGO) users. The purpose of this study was to determine if able-bodied subjects ambulating with the LLPS exhibited gait characteristics typical of RGO users. Five able-bodied persons were trained to ambulate with the LLPS and underwent a motion gait analysis. LLPS...
We analyzed bipedal locomotion of Japanese macaques from the view point of leg joint synergy by the UCM (Uncontrolled manifold) analysis in order to examine how and when hip, knee and ankle joints cooperate so as to suppress the variances of the toe position relative to the hip position. Our results showed that joint synergy is exploited at some moments during walking. For instance, the variance of...
Trans-femoral amputees must regain moving pattern by refined rehabilitation program using loads applied on a prosthetic limb. On the other hand, understanding those loads is indispensable for biomechanical consideration of trans-femoral amputees. However, conventional prosthetic gait training systems cannot measure long continuous walking motions. In this paper, loads applied on trans-femoral prosthesis...
Emerging technologies such as rehabilitation robots (RehaBot) for retraining upper and lower limb functions have shown to carry tremendous potential to improve rehabilitation outcomes. Hstar Technologies is developing a revolutionary rehabilitation robot system enhancing healthcare quality for patients with neurological and muscular injuries or functional impairments. The design of RehaBot is a safe...
Powered lower-limb orthosis is a type of wearable mechanical devices that can serve a wide variety of important biomedical purposes. Due to the constraints associated with the actuation technology, the majority of current lower-limb orthoses are either passive or tethered to external power sources, limiting the functionality of such devices. In this paper, the authors present their preliminary research...
Individuals with quadriceps muscle weakness often have difficulty generating the knee-extension moments required for common mobility tasks. A new device that provides a knee-extension moment was designed to help individuals perform sit-to-stand and stand-to-sit. The knee-extension-assist (KEA) was designed as a modular component to be incorporated into existing knee-ankle-foot-orthoses (KAFO). The...
In the present paper, we propose an algorithm for selecting appropriate transfer support equipment based on the physical ability of the user. In addition, we describe the relationship between features of the human body and the physical burdens during standing. Although several care support devices have been developed, assistive robots are not yet popular because users do not know which devices are...
Ankle-foot orthoses (AFOs) ameliorate the impact of impairments to the lower limb neuromuscular motor system that affect gait. Emerging technologies provide a vision for fully powered, untethered AFOs. The portable powered AFO (PPAFO) provides both plantarflexor and dorsiflexor torque assistance via a bi-directional pneumatic rotary actuator. The system uses a portable pneumatic power source (bottle...
A hybrid neuroprosthesis (HNP) combines lower extremity bracing with functional neuromuscular stimulation (FNS) to restore walking function and enhance the efficiency of ambulation. This report details the development of a novel HNP containing a variable impedance knee mechanism (VIKM) capable of supporting the knee against collapse while allowing controlled stance phase knee flexion. The design of...
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