Date of Award


Document Type

Scholarly Project

Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

First Advisor

Mark Romanick


Ankle; Ankle Injuries; Muscle Activity


Ankle sprains account for 17% to 20% of all injuries in most sports. Other ankle conditions such as posterior tibialis tendon disorder and Achilles tendinosis are quite common in the nonathletic population and require many of the same interventions. Some of these interventions include range of motion, stretching, strengthening and proprioception. Many studies have shown that strength and proprioceptive training are the intervention of choice for those with lateral ankle instability. Many of these studies have supported the use of BAPS in improving proprioception among individuals with lateral ankle instability, however there is only one study examining the use of BAPS for strengthening of the ankle musculature. The purpose of this study was to determine the activity level of lower leg musculature when using the BAPS with and without weights positioned on each quadrant of the board. This study focused on inversion and eversion motions, due to the frequency seen clinically of lateral instability resulting from ankle sprains.

Twenty healthy female and ten healthy male volunteers from the community, faculty, staff, and student population at the University of North Dakota participated in the study. Electrodes were placed over the four muscles of interest (gastrocnemius, soleus, tibialis anterior, and peroneus longus) on the dominant lower extremity of each subject. Following practice repetitions, each subject performed trials of exercises on the BAPS, with and without weights positioned on each quadrant of the board as determined by random selection, in an eversion/inversion direction, while EMG recordings were made from the four muscles of interest.

Results showed no significant difference in the EMG activity of the gastrocnemius, soleus, or anterior tibialis muscles among the 5 different weight placement conditions. A significant difference in EMG activity was found for peroneus longus when comparing all positions except for no weight vs anterolateral, no weight vs anteromedial, and anterolateral vs anteromedial. The difference in EMG activity of peroneus longus was the greatest with weight in the posterolateral position of the BAPS board.

The results indicate an increase in EMG activity of peroneus longus with straight plane exercises. These findings further support the use of straight plane BAPS exercises for strengthening of the PL following an inversion ankle sprain.