Ankle dorsiflexion range of motion influences dynamic balance in individuals with chronic ankle instability

Abstract

PURPOSEBACKGROUND: Individuals with chronic ankle instability (CAI) often have impairments in ankle range of motion (ROM) and balance. There is limited evidence that these impairments are related in individuals with CAI. The purpose of this study was to determine the relationship between ankle dorsiflexion ROM and dynamic balance in individuals with CAI.

Methods: Forty-five participants (age=23.2±2.8 y, height=172.1±10.8 cm, mass=70.6±13.3 kg, Foot and Ankle Ability Measure Sport= 71.2±11.7, Modified Ankle Instability Instrument= 6.4±1.3) volunteered for this study. Ankle dorsiflexion ROM was measured in a weight-bearing position while dynamic balance was measured using the Star Excursion Balance Test (SEBT) in the anterior, posteromedial, and posterolateral directions. Linear regression was used to determine the relationship between ankle dorsiflexion ROM and measures of dynamic balance.

Results: There were fair positive correlations between dorsiflexion ROM and the anterior reach direction (r = .55, r(2) = .31, P < .001), posterolateral reach direction (r = .29, r(2) = .09, P = .03), and the composite SEBT scores (r = .30, r(2) = .09, P= .02). There was little or no relationship between ankle dorsiflexion and the posteromedial reach direction (r = .01, r(2) = .001, P = .47).

Conclusions: Ankle dorsiflexion ROM can influence dynamic balance, specifically the anterior reach portion of the SEBT.

Clinical relevance: Individuals with CAI who demonstrate impairments in dorsiflexion ROM may also demonstrate difficulty with portions of the SEBT. Clinicians may use this information to better optimize rehabilitation programs that address ankle dorsiflexion ROM and dynamic balance.

Level of evidence: 5.

Keywords: Ankle sprain; functional ankle instability; postural control.

Figure 1.

Ankle dorsiflexion range of motion was measured using a weight bearing lunge. The digital inclinometer was aligned with the tibial tuberosity and the anterior tibial crest. The participant was instructed to lunge forward, to dorsiflex the ankle as far as possible, keeping the heel on the floor. The angle of the tibia relative to the floor was used to quantify ankle dorsiflexion ROM.

Figure 2.

Star Excursion Balance Test was performed in the anterior, posteromedial, and posterolateral reach directions.

Figure 3.

Scatter plots for ankle dorsiflexion range of motion and a) anterior reach, b) posteromedial reach, c), posterolateral reach, and d) composite SEBT scores. Ankle dorsiflexion range of motion is expressed in degrees and reach distances are expressed as a percentage of leg length.