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.

Abdominal muscle size and symmetry in normal subjects.

This study was undertaken to establish normal reference ranges for abdominal muscle size and symmetry and to examine the effects on these of gender and age. We studied 123 subjects, consisting of 55 men (aged 21-72 years) and 68 women (aged 20-64 years). Real-time ultrasound imaging of the abdominal muscles was performed. Thickness of internal and external oblique (IO, EO), transversus abdominis (TA), and rectus abdominis (RA), and cross-sectional area (CSA) of RA were measured, and absolute and relative muscle thickness (percent total muscle thickness), order of thickness, and symmetry (percent difference between sides) were determined. Males had significantly larger muscles than females and size was poorly correlated with age. The pattern of relative muscle thickness was RA > IO > EO > TA. Symmetry for total absolute thickness of all three lateral muscles was 8%-9% (mean) but for individual muscles there was asymmetry of absolute size (13%-24%), whereas relative thickness was symmetrical for all muscles. These findings provide robust reference data for the abdominal muscles in normal males and females in order to enable comparison with clinical groups to assess abnormalities and establish sensitivity for evaluating the effectiveness of interventions.