Article

Muscle force testing is one of the more common categories of
diagnostic tests used in clinical practice. Clinicians have little evidence to
guide interpretations of muscle force tests when pain is elicited during testing.
The purpose of this study was to examine the construct validity of
isometric quadriceps muscle strength tests by determining whether the
relationship between maximal isometric quadriceps muscle strength and functional
status was influenced by pain during isometric testing. DESIGN: A cross-sectional
design was used. METHODS: Data from the Osteoarthritis Initiative were used to
identify 1,344 people with unilateral knee pain and Western Ontario and McMaster
Universities Osteoarthritis Index (WOMAC) pain subscale scores of 1 or higher on
the involved side. Measurements of maximal isometric quadriceps strength and
ratings of pain during isometric testing were collected. Outcome variables were
WOMAC physical function subscale, 20-m walk test, 400-m walk test, and a repeated
chair stand test. Multiple regression models were used to determine whether pain
during testing modified or confounded the relationship between strength and
functional status. RESULTS: Pearson r correlations among the isometric quadriceps
strength measures and the 4 outcome measures ranged from -.36 (95% confidence
interval=-.41, -.31) for repeated chair stands to .36 (95% confidence
interval=.31, .41) for the 20-m walk test. In the final analyses, neither effect
modification nor confounding was found for the repeated chair stand test, the
20-m walk test, the 400-m walk test, or the WOMAC physical function subscale.
Moderate or severe pain during testing was weakly associated with reduced
strength, but mild pain was not. LIMITATIONS: The disease spectrum was skewed
toward mild or moderate symptoms, and the pain measurement scale used during
muscle force testing was not ideal. CONCLUSIONS: Given that the spectrum of the
sample was skewed toward mild or moderate symptoms and disease, the data suggest
that isometric quadriceps muscle strength tests maintain their relationship with
self-report or performance-based disability measures even when pain is elicited during testing.
Renforcement musculaire

Langue : ANGLAIS