Passive movement of hip and knee joints decreases the amplitude of soleus H-reflex in stroke patients.
OBJECTIVE
The study aims to investigate the changes of the H-reflex in soleus (Sol-H-reflex) during hip and knee joint movements in stroke patients.


METHODS
The experiments were carried out on five stroke patients with spastic hemiplegia (2 males and 3 females, 48 to 71 years old). Sol-H-reflexes were measured 200 times for each joint movement speed Stimulus was given at random intervals (4 to 5 seconds) during the joint movement. Two movement speeds were used to investigate the effects of movement speed.


RESULTS
For both fast and slow movements, the amplitude of the Sol-H-reflex decreased in the middle flexion phase. In contrast, the amplitude of the Sol-H-reflex increased in the middle extension phase. For the fast movement, the Sol-H-reflex was smaller in only a small angle range during the flexion and extension phase in comparison to the slow movement. The Sol-H-reflex during the flexion phase was significantly smaller than during the extension phase at almost all angles for both speeds. The Sol-H-reflex for both speeds was smaller than the Sol-H-reflex at rest for the whole angle range.


CONCLUSIONS
These results demonstrate the differential effects of Sol-H-reflex modulation in stroke patients when compared with normal subjects.
Graduate School of Science and Technology, Keio University, Japan.
S
S
Tanabe
Y
Y
Muraoka
A
A
Kamiya
Y
Y
Tomita
Y
Y
Masakado
D000368:Aged; D004558:Electric Stimulation; D005260:Female; D006181:H-Reflex; D006429:Hemiplegia / Q000503:physiopathology; D006621:Hip Joint / Q000294:innervation / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000294:innervation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009068:Movement; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D020521:Stroke / Q000503:physiopathology*