Motor Impairment-Related Alterations in Biceps and Triceps Brachii Fascicle Lengths in Chronic Hemiparetic Stroke.

Only 11 people with chronic stroke were studied, and all were moderately to severely impaired (Fugl-Meyer upper-limb scores 12 to 31, maximum 66), so the results do not describe milder stroke or the lower limb. The study measured muscle architecture at one time point. It cannot show when fascicle shortening begins, whether it progresses, or whether it causes the observed impairment. No treatment was given or tested, so it cannot show that stretching, strengthening, positioning, or task training would change fascicle length or function. The control comparison used previously published interlimb norms from 11 healthy age-matched controls, so the control data were not collected during this study. Passive tension and sarcomere length were not measured, so fascicle lengths at the same elbow angle may not represent equivalent points on the muscle force-length curve. Only the long head of biceps brachii and the lateral head of triceps brachii were measured, and one participant was excluded from active triceps analysis. The paper reports interlimb differences, not absolute normal values, and it did not test whether these differences are clinically meaningful for function.

The work received NIH extramural and non-U.S. government research support. The authors declared no financial or personal relationships with other individuals or organizations that could inappropriately influence or bias the work.

Do not conclude that a specific treatment will lengthen the paretic biceps or triceps. The study measured 11 people with chronic stroke and found passive interlimb differences, but it did not test an intervention.