RECOVERY OF MOVEMENT AND FUNCTIONAL ABILITY AFTER STROKE

by Professor Valerie Pomeroy, Centre for Rehabilitation and Ageing,

St George's Hospital Medical School, University of London, England

A model with reflective markers begins to proceed along the walkway.

Introduction

The Centre for Rehabilitation and Ageing (CRAg) movement analysis laboratory at St George's Hospital Medical School has been operational since February 2003. The laboratory supports aspects of the research programs within CRAg, particularly the stroke rehabilitation research program. Led by Professor Valerie Pomeroy and ably supported by Ashreft Sameja (Research Technician), the Stroke Rehabilitation Group comprises a multi-professional team that includes expertise in biomechanics, geriatric medicine, neurophysiology and physiotherapy. Collaborators contribute additional skills, including health economics, muscle physiology and neuroimaging. The focus of the stroke rehabilitation research program is to bring together basic and clinical scientists to investigate neuroscience-based interventions, both conventional and novel, to improve the recovery of neuromuscular weakness and functional ability after stroke. The ultimate goal of our research activity is to reduce the effects of disabling disease and thus increase the level of independence enjoyed by older people.

Movement analysis infrastructure

The new, purpose converted, clinical research laboratories are centrally located in Hunter Wing of St George's Hospital Medical School. Signs have recently been installed to provide clear direction to the Centre for Rehabilitation and Ageing. Accessibility is therefore ensured for all research subjects, whether in-patients arriving via lift or out-patients and healthy volunteers arriving by taxi. The accommodation consists of:

•  reception area

•  neurophysiology laboratory

•  technical workshop

•  movement analysis laboratory

Within this facility we have several key items of equipment, including an 8-camera Vicon motion analysis system, three Bertec forceplates, a Cybex dynamometer and a transcranial magnetic stimulation system. Thus we are able to combine kinematics, kinetics, neurophysiology and muscle function testing. This ensures that we do not just describe how movement changes in response to well defined rehabilitation interventions, but that we are also able to provide an explanation for changes in terms of muscle and nerve function, including transmission in the corticospinal pathways as assessed by transcranial magnetic stimulation.

This accommodation illustrates St George's Hospital Medical School's commitment to research into rehabilitation for older people and complements resources available in related clinical and research areas on the St George's site. The combination of infrastructure will be key to the further development of existing programs of rehabilitation research and expansion into other areas related to disability for older people.

Current research program

Our current research is based on earlier work conducted within the Stroke Association's Therapy Research Unit led by Professors Raymond Tallis and Valerie Pomeroy in the University of Manchester.

During the past few years we have:

•  developed methodologies applicable to the complexities of stroke rehabilitation

•  defined current therapy interventions

•  developed novel, objective, sensitive measures of the aims of therapy intervention

•  identified promising therapy techniques and modes of delivery of intervention

•  completed some exploratory clinical trials

Building on this work we are now conducting several pilot studies and a multicenter clinical trial to evaluate both novel and conventional stroke therapies for which we have received substantial external grant funding.

Measuring movement control during everyday functional tasks - sit to stand.

Current work includes a multicenter clinical trial evaluating the effects of functional strength training on neuromuscular weakness and functional ability of the lower limb after stroke. This research is building on published data suggesting that resistive exercise might not be detrimental after stroke and that outcome might also be better if therapy consists of task-related training. The results of this trial will thus be relevant to everyday clinical practice by providing information about whether more therapy needs to be provided than in current clinical practice and if so which type of therapy produces more benefits.

Other studies are investigating the use of assistive devices to aid basic mobility tasks such as sit-to-stand and walking after stroke. The sensitive measurement of movement afforded by synchronising data from the Vicon system, forceplates and EMG allow sensitive objective measurement to inform and/or support clinical decisions about the benefits or otherwise of such devices.

Summary

During the first year since our lab has been open we have begun several research projects. Many more projects are now being planned. We envisage that the addition of our integrated movement, muscle function and neurophysiology laboratory will further enhance our program which has achieved recognition both nationally and internationally.