Effect of the dose of a Task Specific Training program and Armeo Spring on upper limb motor recovery in chronic stroke: randomized clinical trial

Abstract Introduction: Intensive rehabilitation and task-specific training (TST) are essential for recovery after stroke. Devices such as Armeo Spring allow for increased repetitions while maintaining specificity. The objective was to compare the effect of a high-repetition dose versus a low-repetition dose using a combined program of Armeo Spring and TST on upper limb recovery in patients with chronic stroke. Methods: Randomized, single-blind clinical trial with 20 participants (>6 months post-stroke). Participants were assigned to two groups: High Repetition (HR; 40 hours total, 2 hours/session, 5 days/week) and Low Repetition (LR; 12 hours total, 1 hour/session, 3 days/week) for 4 weeks. The primary outcome measure was the Fugl-Meyer Assessment–Upper Extremity (FMA-UE). Assessments were performed at baseline (T0), post-intervention (T1), and one month (T2). Results: Both groups showed significant improvements in the FMA-UE (p < 0.01). The HR group improved by 10.80 points (SD = 5.92) and the BR group by 5.90 points (SD = 3.54) at T1 and remained stable at T2. The intergroup comparison significantly favored the HR group at T1 and T2 (p < 0.02), with superior benefits also in dexterity, independence, and perception of performance. The effect size was greater in the HR group (d = 0.712) than in the LR group (d = 0.435) between T0 and T1, but at T2, the effect size was small in both groups.Conclusions: Armeo Spring therapy and high-repetition TST proved to be more effective in improving upper limb functionality in patients with chronic stroke at the end of the intervention and at the one-month follow-up. Keywords: stroke; upper limb; dose; task-specific therapy; occupational therapy.