Feasibility of Ballistic Strength Training in Subacute Stroke: A Randomized, Controlled, Assessor-Blinded Pilot Study

To establish the feasibility and effectiveness of a 6-week ballistic strength training protocol in people with stroke.

Randomized, controlled, assessor-blinded study.

Subacute inpatient rehabilitation.

Consecutively admitted inpatients with a primary diagnosis of first-ever stroke with lower limb weakness, functional ambulation category score of ≥3, and ability to walk ≥14 m were screened for eligibility to recruit 30 participants for randomization.

Participants were randomized to standard therapy or ballistic strength training 3 times per week for 6 weeks.

The primary aim was to evaluate feasibility and outcomes included recruitment rate, participant retention and attrition, feasibility of the exercise protocol, therapist burden, and participant safety. Secondary outcomes included measures of mobility, lower limb muscle strength, muscle power, and quality of life.

A total of 30 participants (11% of those screened) with mean age of 50 years (SD 18) were randomized. The median number of sessions attended was 15 of 18 and 17 of 18 for the ballistic and control groups, respectively. Earlier than expected discharge to home (n=4) and illness (n=7) were the most common reasons for nonattendance. Participants performed the exercises safely, with no study-related adverse events. There were significant (P<.05) between-group changes favoring the ballistic group for comfortable gait velocity (mean difference [MD] 0.31m/s, 95% confidence interval [CI]: 0.08-0.52), muscle power, as measured by peak jump height (MD 8cm, 95% CI: 3-13), and peak propulsive velocity (MD 64cm/s, 95% CI: 17-112).

Ballistic training was safe and feasible in select ambulant people with stroke. Similar rates of retention and attrition suggest that ballistic training was acceptable to patients. Secondary outcomes provide promising results that warrant further investigation in a larger trial.