Non-paretic quadriceps activity influences paretic quadriceps activity post-stroke

作者：Lewek Michael D^*; Breslin Rachel; Hlad Lesley; Lanton Alex; John Jamie St

来源：Clinical Neurophysiology, 2010, 121(11): 1962-1967.

DOI：10.1016/j.clinph.2010.04.009

• Quadriceps
• Cerebrovascular accident
• Hemiparesis
• Bilateral muscle activation
• Volitional

Objective: Inappropriate muscle activity is common following stroke. Paretic muscle activation may be influenced by non-paretic volitional activation. We examined the influence of non-paretic quadriceps activation on paretic quadriceps excitability.
Methods: Individuals with chronic stroke performed bilateral and unilateral (paretic and non-paretic) maximum voluntary isometric contractions. Peak torque and muscle activity were compared between conditions. An instrumented tendon tapper elicited a patellar tendon reflex of the relaxed paretic leg while the non-paretic leg was relaxed and pre-activated. The threshold to elicit a paretic quadriceps response was compared between conditions.
Results: During the bilateral MVIC, the paretic quadriceps generated less absolute torque, but greater relative torque than the non-paretic side when normalized to the respective unilateral condition (p < 0.05). During reflex testing, the tendon tapping threshold to elicit paretic muscle and torque responses decreased with non-paretic activity (p < 0.05).
Conclusions: Concurrent non-paretic activation resulted in a relative disinhibition of the paretic quadriceps. The paretic limb's inability to remain inactive during isolated non-paretic contractions implies increased excitation or decreased inhibition of paretic motor pools, although the source remains unknown.
Significance: Unwanted muscle activity during reciprocal tasks (gait training) may be due to contralateral effects of non-paretic muscle activity.

• 出版日期2010-11