Electromyographic response to manual passive stretch of the hemiplegic wrist: accuracy, reliability, and correlation with clinical spasticity assessment and function.
BACKGROUND
The management of spasticity is important in neurorehabilitation and needs to be assessed accurately. The commonly used clinical tools have been criticized for lack of validity and sensitivity.


OBJECTIVE
To investigate the reliability of electromyographic (EMG) response to manual stretches of the hemiplegic wrist and its correlation with clinical assessments of spasticity and physical function.


METHODS
EMG activity was measured in 10 stroke patients and control participants (53.7 +/- 10 and 32 +/- 9.1 years respectively, mean +/- SEM) during 3 cycles of 10 seconds passive manual movements of the wrist at 60 to 360 degrees * s(-1). Isometric maximal voluntary contractions (MVC) strength, range of movement (ROM) of the wrist flexors and extensors, spasticity (Modified Ashworth Scale [MAS]) and hand function (Block and Box Test [BBT]) were also assessed.


RESULTS
EMG activity of the stroke patients increased with velocity from 4% to 40% MVC (P < .001) but there was none in the controls. It was unaffected by repetition and good to moderate reliability occurred at all speeds (ICC, 0.71-0.81). EMG correlated negatively with MVC strength (r = -.9), active wrist flexion ROM ( r = -.8), and hand function scores (r = -.7), but not with clinical measures of spasticity except at the lowest velocity (r = .72).


CONCLUSIONS
Consistent and accurate stretch velocities and EMG responses can be achieved with manual wrist stretches for the assessment of the neural component of spasticity. These objective tests did not correlate well with the standard clinical assessment of spasticity. They showed significant negative relationships with function, indicating that increased reflex excitability contributes to hand disability after stroke.
Sorinola
Isaac O
IO
Division of Applied Biomedical Research, School of Biomedical and Health Sciences, King's College, London, UK.
White
Claire M
CM
Rushton
David N
DN
Newham
Dianne J
DJ
D000328:Adult; D000368:Aged; D004185:Disability Evaluation; D004576:Electromyography / Q000379:methods; D005260:Female; D006429:Hemiplegia / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D009128:Muscle Spasticity / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012018:Reflex / Q000502:physiology; D015203:Reproducibility of Results; D016896:Treatment Outcome; D014953:Wrist / Q000033:anatomy & histology / Q000503:physiopathology*