Affiliations: [a] Program in Physical Therapy, Department of
Kinesiology, Neag School of Education, University of Connecticut, Storrs, CT,
USA | [b] Department of Physical Therapy Education, School of
Health Sciences, Elon University, Elon, NC, USA
Note: [] Corresponding author: A. Williams Andrews, Department of
Physical Therapy Education, School of Health Sciences, Elon University, Elon,
NC 27244, USA. Tel.: +1 336 278 6351; Fax: +1 336 278 6414; E-mail:
andrewsb@elon.edu
Abstract: BACKGROUND: The responsiveness of measurements obtained by hand-held
dynamometry (HHD) is largely unexplored. OBJECTIVE: A secondary analysis of data from a clinical cohort of
patients (N=55) admitted for inpatient rehabilitation following acute stroke
was completed to determine the responsiveness of measures of lower extremity
muscle strength. METHOD: The isometric strength of hip flexion, knee extension, and
ankle dorsiflexion was measured bilaterally in 55 patients using HHD.
Independence in bed-to-chair transfers, level ground gait, and stair
negotiation was determined using an ordinal mobility scale. All measures were
obtained at admission and discharge. RESULTS: Over the course of rehabilitation muscle strength increased
significantly (p⩽ 0.002) in all 3 lower limb muscle actions of both the
weaker and stronger sides. Effect sizes (0.19–0.43) and standardized
response means (0.45–0.79) were mostly small to moderate but tended to be
greater on the weaker side than the stronger side. The minimum detectable
change (95%) values ranged from 33.2 to 87.5 N and were higher on the stronger
than on the weaker side. Receiver operating characteristic curve analysis for
identifying minimal clinically important differences revealed cut-points
between −12.9 and 52.9 Newtons for strength increases differentiating
patients who did and did not demonstrate improved mobility. CONCLUSION: HHD is capable of detecting changes in lower limb
strength after stroke but the responsiveness, as indicated by effect size,
standardized response mean, minimum detectable change and minimal clinically
importance is limited.
