. Author manuscript; available in PMC: 2008 Dec 29.

Published in final edited form as: Am J Epidemiol. 2008 Mar 14;167(9):1090–1101. doi: 10.1093/aje/kwn025

TABLE 4.

Impact of pulmonary function impairment on functional limitation (skeletal muscle strength), California, 2005-2007

Region	Muscle group^*	Mean change in score (pounds^†)^‡	95% confidence interval	p value	Mean change in score (pounds)^§	95% confidence interval	p value
Lower extremity	Quadriceps	-3.6	-2.0, -5.1	0.0001	-3.4	-1.9, -5.0	<0.0001
	Hip flexors	-2.2	-0.92, -3.4	0.0007	-2.2	-0.9, -3.4	0.0008
	Hip abductors	-2.1	-1.1, -3.1	<0.0001	-1.9	-0.9, -3.0	<0.0001
Upper extremity	Elbow flexors	-1.8	-0.8, -2.9	0.0008	-1.9	-0.8, -2.9	0.0007
	Grip	-0.72	-0.14, -1.30	0.015	-0.75	-0.16, -1.34	0.012

A total of 20 subjects could not perform quadriceps or elbow flexor testing, 19 could not perform hip flexor testing, 32 could not perform hip abductor testing, and 10 could not perform grip strength.

^†

One pound = 453.5924 g.

^‡

Per 1-liter decrease in forced expiratory volume in 1 second (FEV₁) controlling for age, sex, and height.

^§

Per 1-liter decrease in FEV₁ controlling for age, sex, height, race, educational attainment, and smoking.