RT Journal Article
SR Electronic
T1 Functional Tests of Leg Muscle Strength and Power in Adults With Cystic Fibrosis
JF Respiratory Care
FD American Association for Respiratory Care
SP 40
OP 47
DO 10.4187/respcare.06224
VO 64
IS 1
A1 Sheppard, Emily
A1 Chang, Kerrie
A1 Cotton, Jackie
A1 Gashgarian, Sonia
A1 Slack, Danny
A1 Wu, Kenneth
A1 Michalski, Anna
A1 Fox, Pat
A1 Stephenson, Anne L
A1 Mathur, Sunita
YR 2019
UL http://rc.rcjournal.com/content/64/1/40.abstract
AB BACKGROUND: Muscle weakness is an important systemic consequence in adults with cystic fibrosis, but it can be challenging to evaluate clinically. This study examined the validity of lower-extremity functional tests to assess quadriceps muscle strength and muscle power.METHODS: The subjects underwent 4 functional tests: 30-s sit-to-stand test, stair-climb power test, vertical jump height, and triple hop distance. Quadriceps muscle strength and power were tested by using a dynamometer (the accepted standard). Quadriceps strength was measured from 5 maximum voluntary isometric contractions to obtain peak torque. Quadriceps power was evaluated from the peak power and peak velocity attained during isotonic contractions of the quadriceps at a preset load of 20% of the peak torque. Pearson correlations were used to determine associations between functional tests and accepted measures of quadriceps strength and power.RESULTS: Fifteen adults with cystic fibrosis (9 males; mean ± SD age, 32 ± 13 y; mean ± SD FEV1% predicted, 73 ± 19) completed the study. The stair-climb power test had the strongest correlations with peak torque (r = 0.84, P < .001) and power (r = 0.65, P = .009). Vertical jump height was moderately correlated with quadriceps strength (r = 0.62, P = .014) and quadriceps peak power (r = 0.51, P = .048). Similarly, triple hop distance had moderate correlations with quadriceps strength (r = 0.78, P = .001) and peak power (r = 0.57, P = .026). The sit-to-stand test was only associated with quadriceps strength (r = 0.55, P = .034).CONCLUSIONS: Functional tests can be applied clinically to measure leg muscle strength and power, with the stair-climb power test having the strongest associations with the standard measures. The utility of using functional tests to evaluate longitudinal changes in muscle function and its association with clinical outcomes should be examined in cystic fibrosis.