Dorsiflexion range of motion significantly influences dynamic balance

The purpose of this study was to examine the relationships between dorsiflexion range of motion on the weight-bearing lunge test (WBLT) and normalized reach distance in three directions on the Star Excursion Balance Test (SEBT). Thirty-five healthy adults (14 males, 21 females, age: 25.9±6.7 years, height: 166.7±22.9 cm, weight: 76.7±22.8 kg) participated. All subjects performed three trials of maximum lower extremity reach in the anterior, posteromedial, and posterolateral directions of the SEBT on each limb to assess dynamic balance. Subjects performed three trials of the WBLT to measure maximum dorsiflexion range of motion. Dependent variables included the means of the SEBT normalized reach distances in the anterior, posteromedial, and posterolateral directions and the mean of the WBLT. Only the anterior direction (mean: 79.0±5.8%) of the SEBT was significantly related to the WBLT (mean: 11.9±2.7 cm), r=0.53 (p=0.001). The r² for this simple linear regression was 0.28, indicating that the WBLT explained 28% of the variance in the anterior normalized reach distance. The WBLT explained a significant proportion of the variance within the anterior reach distance signifying this direction of the SEBT may be a good clinical test to assess the effects of dorsiflexion range of motion restrictions on dynamic balance.