Is the relationship between increased knee muscle strength and improved physical function following exercise dependent on baseline physical function status?

Table 1 Baseline participant characteristics in the entire cohort and when categorised based on baseline physical dysfunction severity

	Total cohort (n = 100)	Baseline physical dysfunction severity
	Total cohort (n = 100)	Mild (n = 38)	Moderate (n = 43)	Severe (n = 19)
Age (years)	62.4 ± 7.3	62.4 ± 6.8	62.2 ± 7.8	63.0 ± 7.6
Women, n (%)	52 (52%)	20 (53%)	22 (51%)	10 (53%)
Height (m)	1.67 ± 0.10	1.67 ± 0.10	1.68 ± 0.09	1.65 ± 0.11
Mass (kg)	82.7 ± 14.3	82.6 ± 15.2	84.0 ± 14.7	79.8 ± 11.5
Body mass index (kg/m²)	29.64 ± 4.08	29.67 ± 4.29	29.69 ± 4.08	29.50 ± 3.85
Knee alignment^a (degrees)	176.8 ± 3.5	176.6 ± 3.7	176.5 ± 3.4	177.9 ± 3.0
Neuromuscular exercise: quadriceps strengthening group	50:50	20:18	24:19	6:13
Bilateral osteoarthritis, yes:no	47:53	15:23	23:20	9:10
Radiographic disease severity^b
Grade 2	22 (22%)	7 (18%)	11 (26%)	4 (21%)
Grade 3	43 (43%)	16 (42%)	17 (40%)	10 (53%)
Grade 4	35 (35%)	15 (39%)	15 (35%)	5 (26%)
VAS average knee pain in the past week, 0–100 mm^c	54.1 ± 15.0	52.8 ± 15.1	51.3 ± 12.5	62.8 ± 17.7^d,e
WOMAC physical function, 0–100^c	39.8 ± 14.1	26.2 ± 8.5	43.2 ± 4.5^d	59.3 ± 8.2^d,e
Knee extensor strength (Nm/kg)	1.45 ± 0.45	1.49 ± 0.48	1.50 ± 0.43	1.27 ± 0.39
Knee flexor strength (Nm/kg)	0.69 ± 0.22	0.69 ± 0.19	0.70 ± 0.24	0.64 ± 0.23

WOMAC Western Ontario and McMaster Universities Osteoarthritis Index, VAS visual analogue scale
^aAnatomic alignment, where neutral alignment is 181° for females and 183° for males. Varus is < 181° for females and < 183 ° for males [19]
^bKellgren and Lawrence grade
^cHigher scores indicates greater pain/dysfunction
^dSignificantly different to mild physical dysfunction (p < 0.05)
^eSignificantly different to moderate physical dysfunction (p < 0.05)

ISSN: 1478-6362