Benjamin L. Patritti

Noise-enhanced balance control in patients with diabetes and patients with stroke

Somatosensory function declines with diabetic neuropathy and often with stroke, resulting in diminished motor performance. Recently, it has been shown that input noise can enhance human sensorimotor function. The goal of this study was to investigate whether subsensory mechanical noise applied to the soles of the feet via vibrating insoles can be used to improve quiet‐standing balance control in 15 patients with diabetic neuropathy and 15 patients with stroke. Sway data of 12 healthy elderly subjects from a previous study on vibrating insoles were added for comparison.

Effects of virtual reality training on gait biomechanics of individuals post-stroke.

OBJECTIVE To evaluate gait biomechanics after training with a virtual reality (VR) system and to elucidate underlying mechanisms that contributed to the observed functional improvement in gait speed and distance. DESIGN A single blind randomized control study. SETTING Gait analysis laboratory in a rehabilitation hospital and the community. PARTICIPANTS Fifteen men and three women with hemiparesis caused by stroke. INTERVENTIONS Subjects trained on a six-degree of freedom force-feedback robot interfaced with a VR simulation. Subjects were randomized to either a VR group (n=9) or non-VR group (NVR, n=9). Training was performed three times a week for 4 weeks for approximately 1h each visit. MAIN OUTCOME MEASURES Kinematic and kinetic gait parameters. RESULTS Subjects in the VR group demonstrated a significantly larger increase in ankle power generation at push-off as a result of training (p=0.036). The VR group had greater change in ankle ROM post-training (19.5%) as compared to the NVR group (3.3%). Significant differences were found in knee ROM on the affected side during stance and swing, with greater change in the VR group. No significant changes were observed in kinematics or kinetics of the hip post-training. CONCLUSIONS These findings are encouraging because they support the potential for recovery of force and power of the lower extremity for individuals with chronic hemiparesis. It is likely that the effects of training included improved motor control at the ankle, which enabled the cascade of changes that produced the functional improvements seen after training.

Design, Control and Human Testing of an Active Knee Rehabilitation Orthotic Device

This paper presents a novel, smart and portable active knee rehabilitation orthotic device (AKROD) designed to train stroke patients to correct knee hyperextension during stance and stiff-legged gait (defined as reduced knee flexion during swing). The knee brace provides variable damping controlled in ways that foster motor recovery in stroke patients. A resistive, variable damper, electro-rheological fluid (ERF) based component is used to facilitate knee flexion during stance by providing resistance to knee buckling. Furthermore, the knee brace is used to assist in knee control during swing, i.e. to allow patients to achieve adequate knee flexion for toe clearance and adequate knee extension in preparation to heel strike. The detailed design of AKROD, the first prototype built, closed loop control results and initial human testing are presented here

Visual EMG Biofeedback to Improve Ankle Function in Hemiparetic Gait

Spasticity in stroke patients interferes with coordinated muscle firing patterns of the lower extremity leading to gait abnormalities. The goal of this study was to improve ankle function during walking by augmenting treadmill gait retraining with a visual EMG biofeedback technique. Eight stroke patients who could ambulate between 0.5 and 0.9 m/s participated in the study. The training consisted of 12 sessions of treadmill walking during which the activity of the tibialis anterior and gastrocnemius lateralis muscles of the affected side was displayed on a computer screen. Targets were shown to indicate to the subject when to activate the monitored muscles. Gait evaluations were performed before and after the training period to test the hypothesis that ankle mechanics improved following the intervention. Improvements in gait function were characterized by changes in temporal gait parameters and lower extremity kinematics and kinetics. Subjects showed an increase in gait speed, time of single leg support on the affected side, ankle power generation at push-off and a reduction in knee extensor moment. These results indicate that treadmill gait retraining augmented via visual EMG-biofeedback facilitates improvements in hemiparetic gait

Physiotherapy Rehabilitation for Individuals with Lower Limb Amputation: A 15-Year Clinical Series

BACKGROUND AND PURPOSE Individuals with amputations are a core group in Australian rehabilitation units that have a long index length of stay. The Repatriation General Hospital (RGH) offers general rehabilitation services to the population of Southern Adelaide (a population of 350,000) and includes an on-site prosthetic manufacturing facility. Using a physiotherapy database at the RGH, we sought to answer the following questions: What are the demographic and clinical characteristics of patients admitted for lower limb prosthetic rehabilitation over 15 years? What are the times to rehabilitation outcomes? How have these changed over 15 years with changes in service delivery? METHODS This paper is a retrospective observational study using a physiotherapy clinical database (1996-2010) of 531 consecutive individuals with lower limb amputation at one South Australian hospital (RGH). There were two changes in service delivery: 1) a multidisciplinary interim prosthetic programme (IPP) introduced in 1998 and 2) removable rigid dressings (RRDs) introduced in 2000. Outcome measures were patient demographics, clinical characteristics and time to rehabilitation outcome markers. RESULTS Mean age was 68 years (standard deviation [SD]: 15), with 69% male, 80% dysvascular and 68% transtibial. The overall median inpatient rehabilitation length of stay (RLOS) was 39 days (interquartile range [IQR]: 26-57). Individuals with amputation entering rehabilitation each year had a higher number of co-morbidities (β: 0.08; 95% confidence interval: 0.05-0.11). Introduction of the IPP was associated with a significant reduction in time to initial prosthetic casting, independent walking and inpatient RLOS. Introduction of RRDs was associated with a significant reduction in time to wound healing, initial prosthetic casting and independent walking. CONCLUSIONS Individuals with amputation were typically elderly dysvascular men with transtibial amputations. Introduction of the IPP and RRDs successfully reduced time to rehabilitation outcomes including independent walking, an outcome that is rarely reported but is of significance to patients and physiotherapists.

Robotic Gait Training in an Adult With Cerebral Palsy: A Case Report

Improved treatments and rehabilitation for cerebral palsy (CP) have led to an increased number of children with CP surviving into adulthood. Adults with CP show an increased prevalence of pain, fatigue, and musculoskeletal dysfunction, leading to a decrease in ambulatory function. Recent work has demonstrated the potential benefits of intensive task‐specific gait training, including the use of robotic‐driven gait orthoses, on motor recovery in children with CP [ 1,2 ]. In contrast, reports of interventions aimed at improving motor function in adults with CP are lacking. This case study reports on the outcomes of a 6‐week intervention of robotic‐assisted gait training administered to a 52‐year‐old woman with right hemiplegia attributable to CP. Improvements were noted in balance, walking speed, and time to negotiate stairs at posttraining and follow‐up. Gait analysis showed an increase in step length and a reduction in the period of double support. In conclusion, robotic‐assisted gait training may be beneficial in enhancing locomotor function in adults with CP.

Comparing a passive-elastic and a powered prosthesis in transtibial amputees

Passive-elastic foot prostheses cannot produce net work. Consequently, passive-elastic foot prostheses are limited in their ability to enable a biologically-realistic gait pattern in transtibial amputees. This shortcoming results in difficulties in balance and walking and leads to high levels of oxygen consumption during locomotion. A powered prosthesis has the potential for overcoming these problems and allowing transtibial amputees to achieve a biologically-realistic gait pattern. In this study, we compared the effects of the Ceterus by Össur, a traditional passive-elastic prosthesis, with those of the PowerFoot Biom (iWalk, Cambridge, MA), a recently-developed powered prosthesis. Gait biomechanics and metabolic cost were compared in a group of 5 transtibial amputees during level-ground walking. The results provided preliminary evidence that the use of a powered prosthesis leads to a decrease in the level of oxygen consumption during ambulation due to improvements in ankle kinematics and kinetics primarily during late stance. An average decrease in oxygen consumption of 8.4% was observed during the study when subjects used the PowerFoot compared to the Ceterus. An average increase of 54% was observed in the peak ankle power generation during late stance. Our results suggest that powered prostheses have the potential for significantly improving ambulation in transtibial amputees.

Fatigue induced changes to kinematic and kinetic gait parameters following six minutes of walking in people with multiple sclerosis

Abstract Purpose: The aim of this study was to examine the effect of 6 min of walking on fatigue, exertion and spatiotemporal, kinematic and kinetic gait parameters in people with multiple sclerosis (MS). Methods: Thirty-four people with MS with moderate levels of disability completed measures of fatigue, exertion and instrumented gait analysis before and after 6-min trials of rest and walking (using a modified 6-min walk test, m6MWT). Ten age- and gender-matched healthy controls completed analysis before and after the m6MWT. Results: The MS group had a significant increase in self-reported fatigue following the m6MWT; however, there was no effect on spatiotemporal gait parameters. During stance on the more affected side ankle dorsiflexion at initial contact decreased, while knee and hip flexor moments and hip power absorption increased. On the less affected side ankle and knee power absorption, and hip extensor moment all increased. Healthy controls showed increases in joint kinetics likely due to increased walking speeds following m6MWT. Conclusion: For people with MS, ankle dorsiflexion angle reduces at initial contact following walking induced fatigue, while increased power absorption at the hip, knee and ankle indicate gait inefficiencies that may contribute to higher levels of fatigue and exertion. Implications for Rehabilitation The modified 6-min walk test (m6MWT) leads to significant increases in self-reported fatigue and exertion in people with MS. Following the m6MWT, there is significantly reduced ankle dorsiflexion angle at initial contact in the more affected leg in people with MS. This reveals an important walking-induced kinematic change that should be the target of future orthotic and strengthening interventions. In people with MS, increased power absorption primarily during the stance phase of gait following the m6MWT reveals important walking-induced muscle weakness that should also be monitored in future strengthening and gait retraining interventions.

Assessing Gait Variability in Transtibial Amputee Fallers Based on Spatial-Temporal Gait Parameters Normalized for Walking Speed

OBJECTIVE To determine whether normalizing spatial-temporal gait data for walking speed obtained from multiple walking trials leads to differences in gait variability parameters associated with a history of falling in people with transtibial amputations. DESIGN Cross-sectional study. SETTING Rehabilitation center. PARTICIPANTS People with unilateral transtibial amputations (N=45; mean age ± SD, 60.5±13.7y; 35 men [78%]) were recruited. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Participants completed 10 consecutive walking trials using an instrumented walkway system. Primary gait parameters were walking speed and step-length, step-width, step-time, and swing-time variability. A retrospective 12-month fall history was obtained from participants. RESULTS Sixteen amputees (36%) were classified as fallers. Variation in gait speed across the 10 walking trials was 2.9% (range, 1.1%-12.1%). Variability parameters of normalized gait data were significantly different from variability parameters of nonnormalized data (all P<.01). For nonnormalized data, fallers had greater amputated limb step-time (P=.02), step-length (P=.02), swing-time (P=.05), and step-width (P=.03) variability and nonamputated limb step-length (P=.04) and step-width (P=.01) variability. For normalized data, only 3 variability parameters were significantly greater for fallers. These were amputated limb step-time (P=.05), step-length (P=.02), and step-width (P=.01) variability. CONCLUSIONS Normalizing spatial-temporal gait data for walking speed before calculating gait variability parameters may aid in discerning variability parameters related to falls histories in people with transtibial amputations. This may help focus on the initial rehabilitation efforts of amputees with a fall history.

A Preliminary Assessment of a Novel Pneumatic Unloading Knee Brace on the Gait Mechanics of Patients With Knee Osteoarthritis

To determine whether a knee brace incorporating inflatable air bladders can alter the net peak external knee adduction moment in persons with medial compartment knee osteoarthritis.