Table 1.

Association between risk factor and asymmetry

Risk factor	Percentage with risk factor*		χ 2 test statistic or Fisher’s exact test (p-value)	OR (95% CI)
	Cases	Controls
Carstairs’ deprivation score			17.7 (0.001)
1	38	62		1.00
2	28	6		7.04 (2.41 – 20.6)
3	18	9		3.20 (1.16 – 8.83)
4 or 5	16	22		1.22 (0.52 – 2.87)
Carstairs’ deprivation score			0.16 (0.689)
1-2	66	69		1.00
3-5	34	31		1.15 (0.59 – 2.24)
Carstairs’ deprivation score			9.56 (0.002)
1	38	62		1.00
2-5	62	38		2.70 (1.42 – 5.16)
Asymmetry in mother’s back	1	4	----- (0.364)+	0.32 (0.03 – 3.11)
Hamstring muscles not tight/ability to touch toes	80	60	6.49 (0.011)	2.65 (1.30 – 5.41)
Poor social skills	1	3	0.00 (0.982)	0.48 (0.04 – 5.41)
No previous cycling	0	0	---	---
No previous attendance at dance classes (girls only)	44	26	4.04 (0.045)	2.26 (1.08 – 4.71)
No previous gymnastics/karate	76	53	7.84 (0.005)	2.77 (1.40 – 5.49)
No previous skating	73	32	24.6 (<0.001)	5.74 (2.88 – 11.5)
No previous horse riding	82	60	8.58 (0.003)	3.13 (1.50 – 6.53)
No previous playing football/hockey	65	55	1.23 (0.267)	1.52 (0.80 – 2.89)
Introduced to swimming pool within first year of life	58	31	10.5 (0.001)	3.08 (1.60 – 5.94)
Ability to swim by age 10 years	56	56	0.00 (0.999)	0.99 (0.53 – 1.87)
Introduced to public pool within first year (≥8)	57	30	10.6 (0.001)	3.11 (1.61 – 6.02)
Introduced to public pool within first year (≥12)	54	29	9.69 (0.002)	2.99 (1.54 – 5.80)
Introduced to public pool within first year (≥24)	34	23	1.72 (0.190)	1.70 (0.84 – 3.44)

*All patients and controls completed every question, therefore the results are presented for 79 cases and 77 controls (with the exception of dancing classes which only applied to girls – 66 patients and 66 controls).

⁺Fisher’s exact test used rather than χ² test due to small numbers.