Effects of a 6-week strength and proprioception training program on measures of dynamic balance: a single-case design

Abstract

Objective: To examine the effects of a 6-week strength and proprioception training program on clinical measures of balance, and to introduce characteristics of a single-case research design that may be beneficial to the athletic training profession as both a research and a clinical tool.

Design and setting: A multiple baseline design across subjects was used to assess the effects of the intervention. The training program was performed three times a week and consisted of manual muscle strengthening and proprioception training for the plantar flexor, dorsiflexor, inversion, and eversion muscle groups.

Subjects: Three subjects (age = 17.6 +/- 1.24 yr, wt = 78.6 +/- 1.07 kg, ht = 186.2 +/- 4.3 cm) who had previously sustained first-degree lateral ankle sprains.

Measurements: Dynamic balance was tested three times a week using a single-plane balance board (SPBB). Each subject was tested for two double-leg conditions (forward/backward, right/left) and one single-leg condition (forward/backward) for each extremity. The dependent variable was the number of times that the balance board made contact with the floor. Visual inspection was used to evaluate whether the treatment resulted in a change of performance.

Results: Although the intervention did not produce obvious improvements in balance for all evaluation criteria for all testing conditions, it is apparent that the strength and proprioception training program positively influenced all three subjects' ability to balance dynamically on an SPBB. A change in mean scores from baseline to intervention phase was evident for all testing conditions. However, a change in slope and level was not as apparent for all testing conditions, especially the single-leg conditions.

Conclusion: The results revealed that the strength and proprioception training program produced improvements in the ability to balance as assessed dynamically on an SPBB.