Date of Award


Document Type

Scholarly Project

Degree Name

Master of Physical Therapy (MPT)


Physical Therapy

First Advisor

Thomas Mohr


Anterior Cruciate Ligament -- surgery; Walking


Physical therapy strives to incorporate innovative and efficient protocols for rehabilitation of anterior cruciate ligament (ACL) surgeries. Research supports the benefits of closed kinetic chain exercises (distal segment of extremity is fixed) over the traditional open kinetic chain exercises (distal segment not fixed). It is theorized that backward walking on inclined surfaces will recruit the knee musculature to a greater extent than forward walking, but there is little research to support this theory. The purpose of this study was to utilize electromyography during treadmill walking to analyze the muscle activity in the lower extremity of individuals were normal and who have had an ACL repair. Seventeen subjects (11 males, 6 females) at the mean age of25 participated in the study.

The results for all subjects were that the muscle activity of the vastus medialis, vastus lateralis, semitendinosus and biceps femoris increased during backward walking in comparison to forward walking. The semitendinosus muscle activity remained relatively equal for forward and backward walking. Increasing the angle of treadmill incline during forward and backward walking generally increased muscle activity. The subjects were classified into two groups, the normal group (N=5) and ACL group (N=12). The results from the two groups varied, however, with small subject number in each group being a large reason for the differences. Future research will need to use a larger number of subjects from both types of repair populations.