Prevalence and risk factor analysis of lower extremity abnormal alignment characteristics among rice farmers

Figures & data

Figure 1 Typical rice cultivation processes including: (A) plowing; (B) seeding;(C) nursing and fertilizing; (D) planting; and (E) harvesting.

Figure 2 Lower extremity alignment measurement methods for: (A) limb length inequality; (B) pelvic angle; (C) femoral antetorsion angle; (D) Q angle; (E) tibiofemoral angle; (F) genu recurvatum angle; (G) tibial torsion angle; (H) rearfoot angle and; (I) medial longitudinal angle.

Abbreviation: Q angle, quadriceps angle.

Table 1 Characteristics of study population (N=249)

Characteristics	N (%)	Mean ± SD	Min–max
Sex
Female	142 (57.03)
Male	107 (42.97)
BMI (kg/m^2)			16–32.47
Normal	175 (70.28)
Overweight (≥25 kg/m^2)	74 (29.72)
Age (years)		45.22±9.29	19–59
Daily working hours (hours/day)		5.92±1.21	3–10
Experience (years)		25.67±11.34	1–46

Abbreviations: BMI, body mass index; Min–max, minimum–maximum; SD, standard deviation.

Table 2 Prevalence of lower extremity malalignment in rice farmers

Characteristics	N	%
Limb length inequality	56	22.49
Pelvic tilt angle	76	30.52
Femoral antetorsion	70	28.11
Q angle	87	34.94
Tibiofemoral angle	79	31.73
Tibial torsion	53	21.29
Genu recurvatum	28	11.24
Foot pronation	90	36.14

Abbreviation: Q angle, quadriceps angle.

Table 3 Lower extremity malalignment and related characteristics in univariate analysis

Characteristics	Limb length	Pelvic tilt angle	Femoral antetorsion	Q angle	Tibiofemoral angle	Genu recurvatum	Tibial torsion	Foot pronation
	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)
Sex
Male	1.00	1.00	1.00	1.00	1.00	1.00	1.00	1.00
Female	1.48 (0.77–2.84)	1.66 (0.93–2.94)	0.44 (0.24–0.79)*	2.59 (1.44–4.64)*	2.09 (1.16–3.77)*	8.61 (1.97–37.68)*	1.14 (0.6–2.17)	0.89 (0.51–1.54)
BMI
Normal	1.00	1.00	1.00	1.00	1.00	1.00	1.00	1.00
Overweight	1.09 (0.55–2.16)	9.31 (4.9–17.48)*	1.63 (0.88–3.03)	1.91 (1.08–3.39)*	1.99 (1.11–3.57)*	1.39 (0.56–3.48)	1.81 (0.94–3.51)	1.56 (0.87–2.81)
Age	1.05 (1.01–1.1)*	1.04 (1.01–1.08)*	1.09 (1.04–1.13)*	1.03 (1–1.07)	1.03 (1–1.07)	1.02 (0.97–1.07)	1.04 (1–1.08)	1.05 (1.01–1.1)*
Daily work hours	1.03 (0.79–1.34)	0.89 (0.7–1.36)	1.07 (0.83–1.36)	1.24 (0.99–1.56)	1.28 (1.01–1.62)*	1.17 (0.82–1.68)	0.85 (0.65–1.12)	1.07 (0.85–1.34)
Years of experience	1.03 (1–1.07)	1.02 (0.99–1.05)	1.07 (1.03–1.11)*	1.05 (1.01–1.08)*	1.05 (1.02–1.08)*	1.02 (0.97–1.07)	1 (0.97–1.04)	1.06 (1.03–1.1)*

Note:

* Significant at P<0.2 level was included into the model of logistic regression.

Abbreviations: Q angle, quadriceps angle; OR, odds ratio; CI, confidence interval; BMI, body mass index.

Table 4 Lower extremity malalignment and related characteristics in multivariate analysis

Characteristics	Limb length	Pelvic tilt angle	Femoral antetorsion	Q angle	Tibiofemoral angle	Genu recurvatum	Tibial torsion	Foot pronation
	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)
Sex
Female		1.7 (0.88–2.37)	0.34 (0.2–0.71)	2.4 (1.32–4.39)*	1.9 (1.03–3.51)*	8.61 (1.97–37.68)*
BMI
Overweight		8.6 (4.7–16.15)*	1.61 (0.82–3.14)	1.94 (1.07–3.55)*	2.05 (1.11–3.78)*		1.57 (0.8–3.1)	1.56 (0.87–2.81)
Age	1.05 (1.01–1.1)*	1.03 (0.99–1.07)	1.04 (0.98–1.1)				1.07 (1–1.14)*
Daily work hours				1.18 (0.91–1.51)	1.23 (0.95–1.58)
Years of experience			1.05 (1–1.11)	1.04 (1.01–1.08)*	1.04 (1.02–1.08)*		0.96 (0.92–1.01)	1.06 (1.03–1.1)*

Note:

* Significant at the P-value <0.05 level.

Abbreviations: Q angle, quadriceps angle; OR, odds ratio; CI, confidence interval; BMI, body mass index.