Table 4.

Potential risk factors (“parameters”) with odds ratios based on the multiple-regression analysis concerning to back pain.

Parameter	N	p-value	Odds ratio	Confidence intervals (95%)
				lower	upper
Female vs. male	269 vs. 841	*0.019	1.48	1.05	2.08
Age groups	1110	*0.005
U19 vs. U15	299 vs. 348	*0.004	1.84	1.21	2.80
U17 vs. U15	463 vs. 348	*0.003	1.66	1.19	2.31
U19 vs. U17	299 vs. 463	0.052	1.11	0.81	1.55
Body mass index (BMI)	1110	0.27	0.97	0.91	1.03
Training experience	1110	0.17	1.04	0.98	1.10
Injuries (overall)	1851	0.80	0.95	0.64	1.01
Spine (yes vs. no)	154 vs. 956	*0.003	1.74	1.21	2.52
Hip/groin (yes vs. no)	245 vs. 865	*0.039	1.40	1.02	1.93
Upper leg (yes vs. no)	298 vs. 812	0.21	1.22	0.89	1.67
Knee (yes vs. no)	381 vs. 729	0.082	1.29	0.97	1.71
Lower leg (yes vs. no)	107 vs. 1003	0.54	1.15	0.74	1.79
Ankle (yes vs. no)	376 vs. 734	0.072	1.30	0.98	1.73
Foot/toe (yes vs. no)	290 vs. 820	0.41	1.13	0.84	1.53
Playing surface	1110	*0.013
Natural vs. hard court/indoor	825 vs. 16	0.46	1.42	0.56	3.63
Artificial vs. hard court/indoor	270 vs. 16	0.85	0.91	0.35	2.39
Natural vs. artificial turf	825 vs. 270	*0.004	1.56	1.15	2.10
Position	1110	0.21
Goalkeeper vs. striker	89 vs. 209	0.066	1.65	0.97	2.80
Goalkeeper vs. midfielder	89 vs. 443	*0.036	1.70	1.04	2.78
Goalkeeper vs. defender	89 vs. 369	0.088	1.54	0.94	2.52
Striker vs. midfielder	209 vs. 369	0.87	1.03	0.72	1.47
Striker vs. defender	209 vs. 369	0.706	0.93	0.65	1.34
Midfielder vs. defender	443 vs. 369	0.58	0.92	0.68	1.24
Weekly training load	1110	0.65
≤3 h vs. ≥6 h	108 vs. 713	0.424	0.81	0.51	1.31

*Significance p < 0.05; additionally the confidence interval (lower to upper limit) of the OR is given to evaluate the influence; n = 1110.