Ankle Joint Dorsiflexion Measurement Using the Deep Squatting Posture

[Purpose] The purpose of this study was to clarify the intrinsic factors influencing the deep squatting posture and to investigate the utility of ankle joint dorsiflexion measurement using this posture. [Subjects] The study subjects were 71 healthy male individuals. [Methods] The subjects were asked to squatted with their heels down and then were divided into 2 groups: possible squatting and impossible squatting. The anthropometric characteristics of the subjects were assessed, and the flexibility and movement range of the lower extremities were tested. To identify the intrinsic factors influencing the deep squatting posture, a dediscriminant analysis was performed by a stepwise procedure. The sensitivity, specificity, and cutoff values for the factors were evaluated by receiver operating characteristic curve analysis. [Results] Of the 71 participants, 55 were assigned to the possible squatting group and the remaining to the impossible squatting group. Analysis revealed that body weight and ankle dorsiflexion flexibility were significantly associated with ability to assume the deep squatting posture. In particular, ankle dorsiflexion flexibility was strongly associated with the ability to assume this posture. [Conclusion] The impossible squatting group showed reduced ankle dorsiflexion. Thus, the deep squatting posture is useful for easy and objective method for measuring ankle joint dorsiflexion flexibility.