The effects of rehabilitation training on lower extremity muscle function in patients convalescing after stroke as revealed by velocity-encoded phase-contrast MRI

Abstract

Objective To assess the effects of rehabilitation training on lower extremity muscle function in stroke patients using velocity-encoded phase-contrast MRI ( VE-PC MRI). Methods Twenty-nine stroke patients at the convalescence stage were divided into a treatment group (14 cases) and a control group (13 cases).The subjects performed calf muscles stretches supine in a scanner bed with voluntary ankle flexion-extension movements.Imaging data were collected from the tibialis anterior muscle (TA),the medial head of the gastrocnemius (MG) and the soleus muscle (SOL) of the affected side.The treatment group also underwent rehabilitation including treadmill training,while the control group received only walking training without the treadmill.Barthel index (BI) and Berg balance scale (BBS) scores were measured after rehabilitation. Results Compared with baseline,the contraction velocity of the TA (phases 2 to 7),the MG (phases 12 to 18 ) and the SOL (phases 13 to 16) on the affected side increased significantly in the treatment group.In the control group,the contraction velocity of the calf muscles on the affected side improved,but fewer phases were significant-for the TA phase 4,for the MG phases 13 to 15 and for the SOL phase 15.In both groups,BBS and BI scores improved significantly compared with baseline.The average improvement in the treatment group was significantly greater than that in the control group. Conclusions Rehabilitation including treadmill training can improve calf muscle contraction function on stroke patients' affected side,and also their ADL performance and balance.VE-PC MR1 can provide quantitative in vivo measurements of the contraction function of stroke patients' calf muscles. Key words: Stroke; Calf; Magnetic resonance imaging; Rehabilitation