Shota Itoh, RPT, PhD, Hiroki Tanikawa, RPT, DMSc, Hikaru Kondo, RPT, PhD, Sora Ozeki, RPT, MS, Toshiki Ito, RPT, Kenta Fujimura, OTR, DMSc, Toshio Teranishi, RPT, DMSc
Jpn J Compr Rehabil Sci 16: 9-18, 2025
Objective: The current study aimed to evaluate the
reliability of muscle strength measurements using a
hand-held dynamometer (HHD) in patients with
chronic stroke. Further, it examined the minimal
detectable change (MDC95).
Methods: Patients who presented with chronic stroke
hemiplegia for > 180 days post-stroke onset were
analyzed. Muscle strength in the paretic lower limb
was assessed using an HHD, and gait speed was
evaluated.
Results: For hip flexion, hip adduction, hip abduction,
knee extension, ankle dorsiflexion, and ankle
plantarflexion, the intra-rater reliability of the muscle
strength measurements, as assessed using the intraclass
correlation coefficient (ICC), ranged from 0.989 to
0.998. The inter-rater reliability, as assessed using
ICC, ranged from 0.886 to 0.939. Bland-Altman
analysis did not indicate systematic errors, and the
MDC95 of each joint movement was calculated.
Muscle strength in hip flexion, hip adduction, knee
extension, ankle dorsiflexion, and ankle plantarflexion
were significantly associated with gait speed, but not
with hip abduction strength. The MDC95 of each
muscle strength measurement was established, thereby
providing a criterion for detecting actual changes that
exceed the measurement error.
Conclusions: The HHD had a high reliability in
measuring lower limb muscle strength in patients with
chronic stroke hemiplegia. Moreover, an association
was found between individual muscle strength and
gait ability. Based on this study, specific target muscles
for interventions that aim to improve gait speed can be
identified. Further, the use of MDC95 allows for a more
accurate assessment of the intervention effects.
Key words: Stroke, Hand-held dynamometer (HHD), Muscle strength, Reliability, Minimal detectable change