Article

Further clarification is needed with regard to the degree of atrophy
in individual muscle groups and its possible relationship to joint torque deficit
poststroke. The purpose of this study was to investigate quadriceps
and hamstring muscle volume and strength deficits of the knee extensors and
flexors in people with chronic hemiparesis compared with a control group.
This was a cross-sectional study. METHODS: Thirteen individuals with hemiparesis
due to chronic stroke (hemiparetic group) and 13 individuals who were healthy
(control group) participated in this study. Motor function, quadriceps and
hamstring muscle volume, and maximal concentric and eccentric contractions of the
knee extensors and flexors were assessed. RESULTS: Only the quadriceps muscle of
the paretic limb showed reduced muscle volume (24%) compared with the
contralateral (nonparetic) limb. There were no differences in muscle volume
between the hemiparetic and control groups. The peak torque of the paretic-limb
knee extensors and flexors was reduced in both contraction modes and velocities
compared with the nonparetic limb (36%-67%) and with the control group (49%-75%).
The nonparetic limb also showed decreased extensor and flexor peak torque
compared with the control group (17%-23%). Power showed similar deficits in
strength (12%-78%). There were significant correlations between motor function
and strength deficits (.54-.67). LIMITATIONS: Magnetic resonance imaging coil
length did not allow measurement of the proximal region of the thigh.
CONCLUSIONS: There were different responses between quadriceps and hamstring
muscle volumes in the paretic limb that had quadriceps muscle atrophy only.
However, both paretic and nonparetic limbs showed knee extensor and flexor torque
and power reduction.

Langue : ANGLAIS