P-2-01-17
SURFACE EMG DURING ISOKINETIC FLEXION-EXTENSION OF THE KNEE IN HEMIPARETIC PATIENTS: ONE YEAR LATER CONTROL.
G. Felicetti A. Contardi, R.Rovescala, G. Notarangelo, R.Maestri*
Salvatore Maugeri Foundation - IRCCS, Institute of Montescano - Pavia, Italy
Division of Physical Medicine and Rehabilitation *Department of Biomedical Engineering
In this study the authors studied surface EMG activity of vastus medialis, vastus lateralis, semitendinous and femorale biceps muscles during isokinetic flexion-extension of the knee in a group of 26 patients affected by normotonic hemiparesis.
Twenty healthy subjects, same age of the hemiparetic patients, chosen as control group. Each subject underwent two tests of 5 flexion-extension of the knee at 60 and 120 degrees/second. The hemiparetic patients performed the tests first on the healthy and then on the paretic side at the end of the recovery and one year after the stroke.
lsokinetic and surface EMG signals were recorded simultaneously using a customized programme.
The time lapse between the appearance of EMG activity and the torque zero was analyzed.
The data we obtained showed two trends of EMG activity: in the healthy subjects and in the healthy and paretic side of 10 hemiparetic subjects we observed the typical changing of agonistic-antagonistic activity; in a group of 16 patients EMG activity persisted in the flexor muscles even during extensor contraction; the persistence of surface EMG activity in the paretic sides was observed one year late.
The temporal numerical data showed a high statistical difference between healthy and hemiparetic subjects both on the healthy and particularly on the paretic side. The presence of EMG activity flexor muscles could represent co-activation and or persistence of changed motor schemes after stroke. All patients show the same altered schemeseven one year after the end of rehabilitation test.
P-2-01-18
Influence of Obstructive Factors on Muscle Strength and Independence from Synergy of Hemiplegic Lower Limb
T. Yokoyama, K. Kawahira, A. OGATA and N. Tanaka
Department of Rehabilitation and Physical Medicine, Faculity of Medicine, Kagoshima University, Kagoshima, Japan
Purpose: The effect of obstructive factors (OF) on muscle strength and independence from synergy of hemiplegic lower limb before and after exercise therapy were studied.
Subject and Method: 26 patients with hemiplegia received 4 weeks intensive exercise therapy focused on hemiplegic lower limbs for 1.5hrs/day (repeats of several kinds of assisted or voluntary movements of lower limbs being coordinated and free from synergy). 14 out of 26 patients had slightly aphasia, agnosia and severe sensory loss. Independence from synergy was evaluated by Ueda's grading. Muscle strength of lower limb (knee extension/flexion) was measured with Cybex 6000 at sitting position (isokinetic: 60°/sec, isotonic: extension 10 Kg, flexion 5 Kg, isometric:knee flexion at 60°).
Results: On admission, the correlation between Ueda's grade and muscle strength were higher in patients without OF (r=0.55〜0.92) than in patients with OF (r=0.44〜 0.57). After 4 weeks intesive exercise therapy, these correlationa were slightly decreased in patients without OF, but markedly decreased in those with OF.
Conclusion: There was a positive correlation between muscle strength of hemiplegic lower limb and independence from synergy in pts with OF, but not in those with OF, and these corrlations were reduced after intensive exercise therapy. These results suggest that the patients with OF might have some discrepansy between voluntary movements and ordered movements. The independence of synergy and muscle strength after exercise is not always proportional.
