Hip adduction and abduction strength in different test positions and their relationship to previous groin injuries in women footballers

Figures & data

Figure 1. Testing setup for hip strength assessment using frame-stabilized dynamometer system device. a − 0° hip angle abduction. b − 0° hip angle adduction. c − 45° hip angle abduction. d − 45° hip angle adduction.

Table 1. Descriptive statistics and agreement between testing positions.

Variable	Hip flexed (45°) Mean (SD)	Hip extended (0°) Mean (SD)	Diff Mean (95% CI)	t-test			correlation
				t	p	d	r	p
add [Nm/kg]	2.53 (0.41)	1.06 (0.21)	1.47 (1.42; 1.53)	51.57	<0.001	5.26	0.799	<0.001
abd [Nm/kg]	2.38 (0.33)	1.15 (0.17)	1.23 (1.18; 1.28)	52.907	<0.001	5.40	0.761	<0.001
abd/add [ratio]	0.95 (0.13)	1.11 (0.17)	−0.15 (−0.18; −0.12)	−9.971	<0.001	1.02	0.510	<0.001

add – adduction strength. abd – abduction strength. abd/add – ratio between abduction and adduction strength. SD – standard deviation. d – Cohen’s d effect size. Diff – differences between the two positions calculated as Hip flexed minus Hip extended test results. p – statistical significance. t – t-test statistics. r – Pearson correlation coefficient.

Table 2. Percentiles for maximal isometric adduction and abduction strength and abduction to adduction strength ratio.

Percentiles	Hip flexed (45°)			Hip extended (0°)
	Add45° [Nm/kg]	abd45° [Nm/kg]	abd45°/add45° [ratio]	Add0° [Nm/kg]	abd0° [Nm/kg]	abd0°/add0° [ratio]
10	2.03	1.95	0.81	0.80	0.93	0.92
20	2.14	2.10	0.85	0.87	1.00	0.98
30	2.31	2.19	0.87	0.95	1.06	1.01
40	2.44	2.27	0.91	0.99	1.12	1.04
50	2.52	2.38	0.95	1.06	1.15	1.10
60	2.58	2.47	0.98	1.10	1.20	1.12
70	2.78	2.56	1.02	1.15	1.25	1.17
80	2.86	2.68	1.06	1.22	1.28	1.23
90	3.10	2.80	1.11	1.32	1.36	1.32

add – adduction strength. abd – abduction strength. abd/add – ratio between abduction and adduction strength.

Table 3. Receiver operating statistics for distinguishing between women football players with and without previous groin pain.

Variables		Area (Std. error)	p
Hip flexed (45°)	add	0.524 (0.096)	0.816
	abd	0.594 (0.085)	0.356
	abd/add	0.530 (0.102)	0.768
Hip extended (0°)	add	0.570 (0.097)	0.493
	abd	0.614 (0.093)	0.261
	abd/add	0.734 (0.091)	0.021*

Area – Area under the curve (AUC). Std. error – standard error. p – statistical significance for null hypothesis: true area = 0.5. * - p < 0.05. add – adduction strength. abd – abduction strength. abd/add – ratio between abduction and adduction strength. Area values equal to 0.5 indicate that a test is no better at discriminating between previous groin pain and groin-pain-free players than chance alone. Values equal to 1 represent a test with perfect accuracy.