Topics in Exercise Science and Kinesiology Volume 3: Issue 1, Article 9, 2022. The purpose of this study was to measure lower extremity muscle activity during recumbent stepping under varied conditions. We hypothesized that different stepping conditions would lead to significant changes in muscle activity. Fifteen healthy adults (4 men, 11 women; mean age 24.5 ± 7.7 yrs) provided informed consent to participate. During a single session, electromyography (EMG) was used to measure muscle activity of the tibialis anterior (TA), medial gastroc (MG), rectus femoris (RF), and biceps femoris (BF) muscles as a percent of maximal voluntary contraction (%MVC) during five different stepping conditions: 1) Stepping with no foot strap (SnS), 2) Stepping with a strap (SS), 3) Pulling with toes with a strap (PullTS), 4) Pushing with heel with a strap (PushHS) and, 5) Pushing with toes with a strap (PushTS). There were significant differences (p < 0.05) in muscle activity between stepping conditions for the TA, MG and RF muscles. TA muscle activity was greatest (21.3 ± 13.7%MVC) during the PullTS condition, MG activity was greatest (7.4 ± 3.4%MVC) during the PushTS condition, and RF activity was greatest (12.9 ± 6.1%MVC) during the PullTS condition. There were no significant differences for the BF between conditions. Different recumbent stepping conditions can significantly alter lower extremity muscle activity with the largest changes observed in the ankle muscles. Therefore, when prescribing recumbent stepping exercise, clinicians should be aware of how factors such as stepping direction, the use of a foot strap, and verbal cueing can alter lower extremity muscle recruitment to optimize therapeutic benefit.
Hoff et al. (Fri,) studied this question.