Effect of pelvic, hip, and knee position on ankle joint range of motion.

OBJECTIVE: To determine if pelvic posture, hip, and knee positions influence range of motion about the ankle joint.

STUDY DESIGN: Quasi-experimental repeated measures.

SETTING: Biomechanics laboratory in a university setting.

PARTICIPANTS: Eleven men and six women free of ankle joint trauma.

MAIN OUTCOME MEASURES: Range of motion about the ankle joint.

RESULTS: ANOVA revealed a significant difference for position main effect on ankle joint range of motion (p=0.01). Post-hoc tests revealed that ankle joint range of motion significantly decreased as participants moved from flexion (i.e., 90 degrees hip and 90 degrees knee), to supine, and to long sitting (47.3 degrees , 38.8 degrees , and 16.4 degrees ; p<0.05). No significant differences were revealed for pelvic posture (p=0.64).

CONCLUSIONS: These findings indicate that pelvic posture may not influence ankle joint range of motion regardless of hip and knee joint positions. However, the combination of hip flexion and knee extension (i.e., long sitting) produces the greatest deficits in ankle joint range of motion.