No Association Between Hamstrings-to-Quadriceps Strength Ratio and Second ACL Injuries After Accounting for Prognostic Factors: A Cohort Study of 574 Patients After ACL-Reconstruction

Sports Medicine - Open

Table 4 Post-hoc logistic regression analysis of association between relative peak torque of the hamstrings and quadriceps strength on the ACL reconstructed side, and the LSI for the hamstrings and quadriceps with second ACL injuries

	Value	n (%) of event	Univariable*		Area under ROC curve (95%CI)	Multivariable**
	Value	n (%) of event	OR (95%CI)	p value	Area under ROC curve (95%CI)	OR (95%CI)	p value
HQ-ratio (ACL reconstructed side) (%)	30.9–< 52.8	33 (17.2%)
	52.8–< 61.0	14 (7.3%)
	61.0–139.0	17 (8.9%)	0.97 (0.95–1.00)	0.025	0.60 (0.52–0.67)	0.98 (0.95–1.01)	0.16
Relative peak torque of hamstrings strength, reconstructed (N m kg⁻¹)	0.33–< 1.37	29 (15.3%)
	1.37–< 1.64	16 (8.4%)
	1.64–2.51	19 (10.0%)	0.52 (0.22–1.21)	0.13	0.57 (0.49–0.64)	0.47 (0.18–1.27)	0.14
Relative peak torque of quadriceps strength, reconstructed (N m kg⁻¹)	1.06–< 2.42	19 (10.0%)
	2.42<–2.85	19 (10.0%)
	2.85–4.07	26 (13.7%)	1.21 (0.72–2.03)	0.47	0.53 (0.45–0.61)	0.96 (0.52–1.78)	0.91
LSI hamstrings (%)	42.5–< 93.0	19 (9.9%)
	93.0–< 102.5	25 (13.1%)
	102.5–140.0	20 (10.4%)	1.00 (0.98–1.02)	0.83	0.52 (0.44–0.59)	1.00 (0.98–1.02)	0.91
LSI quadriceps (%)	40.2–< 90.2	22 (11.5%)
	90.2–< 98.7	15 (7.8%)
	98.7–129.4	27 (14.1%)	1.02 (0.99–1.04)	0.14	0.55 (0.47–0.63)	1.01 (0.98–1.03)	0.68

A bold p-value indicates a significance (p < 0.05). ACL anterior cruciate ligament, CI confidence intervals, HQ hamstrings-to-quadriceps, LSI limb symmetry index, n numbers, N m Newton meters, OR odds ratio, ROC receiver operating curve
*All analyses were performed with univariable logistic regression
**Multivariable logistic regression model including hamstrings-to-quadriceps strength ratio (ACL-reconstructed side), relative peak torque of hamstrings strength, relative peak torque of quadriceps strength, LSI hamstrings, and LSI quadriceps. Area under ROC curve with 95% CI for multivariable model = 0.69 (0.62–0.76)