CLOCKWISE FROM BOTTOM: SUE ANN SISTO, PT, PHD, ASSOCIATE PROFESSOR, PHYSICAL MEDICINE AND REHABILITATION (PM&R), UMDNJ-NEW JERSEY MEDICAL SCHOOL (NJMS), CLINICAL ASSISTANT PROFESSOR OF PHYSICAL THERAPY, UMDNJ-SCHOOL OF HEALTH RELATED PROFESSIONS, AND DIRECTOR, HUMAN PERFORMANCE AND MOVEMENT ANALYSIS LABORATORY (HPMAL), KESSLER MEDICAL REHABILITATION RESEARCH AND EDUCATION CORPORATION; PIERRE ASSELIN, MS, BIOMEDICAL ENGINEER, HPMAL; GAIL F. FORREST, PHD, ASSISTANT PROFESSOR, PM&R, NJMS, RESEARCH SCIENTIST II, HPMAL; JOHN MORES, MS, LAB TECHNICIAN, HPMAL; KAREN J. NOLAN, PHD, INSTRUCTOR, PM&R, NIDRR POST-DOCTORAL RESEARCH FELLOW, HPMAL; MATHEW YAROSSI, BS, BIOMEDICAL ENGINEER AND STUDY COORDINATOR; ANDREW KWARCIAK, MS, BIOMEDICAL ENGINEER, HPMAL.

Bipedal and wheelchair locomotion in stroke and spinal cord injury by Sue Ann Sisto

Persons with stroke and spinal cord injury (SCI) suffer from problems that limit their mobility. Studies underway at the Human Performance and Movement Analysis Laboratory (HPMAL) at the Kessler Medical Rehabilitation Research and Education Corporation (KMRREC) address potential rehabilitation interventions that are best suited to improve mobility and enhance quality of life.

The HPMAL was established in 1997 under my direction. As a physical therapist and clinician, I focused the research on clinically relevant rehabilitation interventions that have the potential to improve functional mobility and prevent secondary complications associated with disability. The laboratory research has focused primarily on bipedal (gait) and wheelchair locomotion in two major patient populations — stroke and spinal cord injury.

Each year 700,000 people experience a new or recurrent stroke. Stroke is the leading cause of serious long-term disability in the U.S. and can cause significant functional limitations in activities of daily living, such as walking. The HPMAL uses instrumented gait analysis to routinely measure post stroke gait. Clinical gait analysis involves the collection of quantifiable information, such as kinematics (3D joint motion), kinetics (forces and moments), and electromyography (EMG) to objectively measure changes in walking patterns. Research in the HPMAL has focused on evaluating rehabilitation interventions to improve post stroke gait. Ongoing research includes how spasticity interventions may influence walking biomechanics and efficiency.

The HPMAL has recently received a mobile pedobarography system to objectively measure dynamic pressures on the plantar surface of the foot. This research was initiated by Karen J. Nolan, PhD, a postdoctoral fellow and principal investigator, examining ankle foot orthotics (AFOs) in patients with hemiplegia due to a stroke. Her research combines foot pressure measurements with kinematics and kinetics to provide information on how AFO affects plantar loading patterns during gait. Results from this investigation could guide prescription, evaluation, and modification of AFOs to ultimately improve walking ability, balance and comfort in post stroke patients.
Approximately 11,000 patients experience traumatic spinal cord injury each year in the U.S. The HPMAL has investigated several areas in SCI research, including bipedal locomotion using body weight supported walking, wheelchair propulsion, and the reduction and prevention of secondary conditions such as cardiovascular disease through diet and exercise.

Over the last three years Gail Forrest, PhD, principal investigator, has been involved in research related to the effect of locomotor training (LT) as a rehabilitation intervention for individuals with a chronic SCI. The main objective is to address whether the neuromusculoskeletal system of the lower limbs can respond to levels of limb loading and repetitive stepping. Specifically, the aim of the research is to determine if LT can modify motor output, change muscle firing patterns in the legs, increase muscle volume, slow down the loss in bone, alter the autonomic nervous system, and improve functional locomotor capacity or increase ability to stand overground. To date, there is limited research that has reported the effect of LT on individuals who have an incomplete SCI with no motor function below the level of injury. Our research would provide baseline data as the first step of a series of investigations where LT could be used with another modality to examine the improvement of functional recovery, or help to alleviate long-term secondary complications (such as severe muscle atrophy and bone loss) that often follow SCI.
Another focus of SCI research is repetitive strain injuries that are potentially related to prolonged wheelchair use. Nearly 70% of upper limb pain in SCI is due to repetitive strain injuries. Currently, I am site director on a multi-site study entitled “Collaboration on Upper Limb Pain in Spinal Cord Injury” (CULP-SCI). This research is designed to evaluate upper limb kinematics and kinetics during standardized wheelchair propulsion.

Testing instrumentation for ongoing HPMAL research protocols: a) kinematic and EMG testing during body weight support treadmill training in SCI; b) maximum plantar pressures collected using pedobarography; c) smartwheel measures kinetics during manual wheelchair propulsion; d) kinematics and kinetic data measuring post stroke gait during one walking trial along an 8 meter walkway. Pictures by Andrew Kwarciak, MS, and Karen J. Nolan, PhD.

Through this line of research, the HPMAL has made great strides toward understanding the relationship between upper limb pain and wheelchair propulsion biomechanics. The current limitation on this important work is the lack of studies that evaluate individuals with tetraplegia (IWT) who have a greater prevalence of shoulder pain due to shoulder muscle weakness and shoulder instability. We have been awarded a new grant to evaluate the biomechanical predictors of shoulder pain and pathology during manual wheelchair propulsion in persons with tetraplegia. This will be accomplished through a biomechanical analysis of wheelchair propulsion including upper limb kinematics and kinetics using two force-sensing instrumented wheels. Shoulder pain will be measured using a wheelchair propulsion shoulder pain questionnaire and a standardized clinical physical examination. Injury will be measured using MRI imaging and radiographic scores of bony changes. As principal investigator of this new grant, it is my desire that we increase our understanding of the motions and forces that predispose IWT to upper limb pain and injury. We hope to be able to make specific recommendations to help clinicians in the prescription and set-up of wheelchairs and exercise interventions for shoulder pain in individuals after SCI who use manual wheelchairs.

Persons with SCI have a greater risk for cardiovascular disease than their age-matched able-bodied peers. This is due to inactivity and loss of muscle mass. I have demonstrated positive changes in the cardiovascular risk factors, including weight loss, an increase in muscle mass, a decrease in fat mass and improved lipid profiles for those individuals after SCI who become involved in activities that promote weight loss and exercise. This potentially will lead to improvements in quality of life through greater ease of wheelchair locomotion, less upper limb pain during wheelchair propulsion and transfers.

Looking to the future, I would like to provide the field of physical rehabilitation with evidence to support clinical practice. The ultimate goal is to improve mobility and quality of life for individuals with disabilities.

Sue Ann Sisto, PT, MA, PhD, is the director of the Human Performance and Movement Analysis Laboratory (HPMAL) at the Kessler Medical Rehabilitation Research and Education Corporation, (KMRREC). She received her bachelor’s degree in physical therapy from St. Louis University and a master’s and PhD in pathokinesiology and physical therapy research from New York University. Dr. Sisto is an associate professor of physical medicine and rehabilitation and a clinical assistant professor of physical therapy at UMDNJ-New Jersey Medical School and UMDNJ-School of Health Related Professions. Her studies have involved collection of 3D gait analyses, metabolics, kinetics (using force plates and force sensing wheelchair pushrims) and blood assays. She is on the board of the Gait and the Clinical Movement Analysis Society, actively involved in the American Congress of Rehabilitation Medicine, on the Scientific Review Committee of the American Physical Therapy Association’s Foundation for Physical Therapy and the New Jersey American Physical Therapy Association Research Committee and the Rehabilitation Research Advisory Board of the National Stroke Association. Dr. Sisto serves on the editorial boards of several journals including the Journal of Spinal Cord Medicine, assistive technology panel of the Disability & Rehabilitation journal and the Journal of Head Trauma Rehabilitation.