Date of Award

Fall 12-2016

Degree Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

Bill Holcomb

Committee Chair Department


Committee Member 2

Trent Gould

Committee Member 2 Department


Committee Member 3

Scott Piland

Committee Member 3 Department


Committee Member 4

Gary Krebs

Committee Member 4 Department



Neuromuscular electrical stimulation (NMES) is the use of an electrical current for the purpose of eliciting a muscular response, and these treatments are most often used clinically for the specific purpose of increasing quadriceps strength. It is commonly accepted that the effectiveness of NMES for this purpose is primarily determined by the NMES training intensity. However, spatially limited motor unit recruitment, fatigue and discomfort negatively impact NMES-induced torque, which subsequently reduces NMES training intensities. Due to the importance of NMES training intensity, a substantial amount of research has focused on strategies designed to increase NMES-induced torque production, as well as to reduce NMES-induced fatigue and discomfort. However, authors have indicated that additional strategies are needed, as many of the strategies supported by empirical evidence cannot be easily applied in clinical settings.

The Kneehab® XP (Theragen LLC, Leesburg, VA) is an electrical stimulator that incorporates a novel multipath current distribution strategy (m-NMES) marketed to address the primary factors limiting NMES training intensity, and as such it has gained a significant amount of attention in the literature. Relative to conventional NMES (c-NMES), authors have reported improved outcomes while using the novel m-NMES but due to a series of methodological limitations the influence of the multipath current distribution strategy on these outcomes remains unclear. Therefore, the purpose of this project was to further investigate the influence that m-NMES has on NMES related outcomes.

A convenience sample of 21 participants completed two basic studies designed to compare the influence of m-NMES and c-NMES on maximum comfortable stimulus intensity and NMES-induced peak torque, as well as fatigue and discomfort related outcomes. The statistical analyses of each study did not reveal any significant differences across the two conditions deemed to be clinically relevant. Therefore, it does not appear that the novel multipath current distribution method influences the outcomes included during this project in a clinically meaningful manner. The large declines in NMES-induced torque that occurred, irrespective of the NMES condition, suggest the need for the development of additional strategies.