Table 1.

Increasing angles via the posterior approach from the piriformis to the obturator externus. The muscle name indicates the increased angle measured after muscle resection. The data are presented as averages ± standard deviations

	Piriformis	Superior gemellus	Obturator internus	Inferior gemellus	Obturator externus	Ischiofemoral ligament
Hip flexion 0°	1.8° ± 1.0°	3.2° ± 0.5°	2.7° ± 0.8°	3.4° ± 1.7°	3.8° ± 1.1°	8.4° ± 5.1°
Hip flexion 30°	1.6° ± 1.3°	2.6° ± 1.3°	3.8° ± 1.1°	4.7° ± 1.3°	4.6° ± 1.3°	15.5° ± 5.7°
Hip flexion 60°	1.6° ± 1.1°	2.0° ± 0.9°	2.1° ± 2.0°	1.1° ± 2.9°	2.5° ± 3.8°	10.2° ± 5.8°