# The Reverse Lunge: A Descriptive Electromyographic Study
## 4 Discussion
### Peak Muscle Activity Throughout Reverse Lunge Movement  
This study analyzed the reverse lunge in two halves: lowering and rising, each comprising ~50% of the lunge movement. Each half phase was then divided into subphases. Lead limb phases of the lowering half included toe off, backswing, ground contact, knee descent, and max descent (Table 1). The lead limb phases of the rising half are knee ascent, front swing, and terminal foot plant (return to bilateral stance) (Table 1). The stationary limb phases of the lowering half are weight acceptance, single limb stance, knee flexion, and max descent (Table 2). The stationary limb phases of the rising half are knee extension, forward weight shift into single limb stance, and terminal foot plant (return to bilateral stance) (Table 2). The phases of movement largely impacted the consistency of peak muscle activation during the reverse lunge. This makes sense when kinesiologic principles are considered. During the movement, each of the considered muscles may be activated in a concentric, eccentric, or isometric manner. Some muscles work as prime movers and others work as stabilizers according to their EMG output.  
There is limited evidence in the literature analyzing where peak muscle activation occurs during lunges (forward, lateral, reverse). This study attempted to compare peak muscle activations between the rising and lowering halves of the reverse lunge by using a heel switch to mark the phases. When analyzing where peak muscle activity occurred, the data suggested that all four muscles of the stationary limb and the lead limb RF displayed their most consistent peak muscle activations in the rising half of the lunge. Using kinesiological principles, it may be likely that the peaks of the stationary limb and lead limb RF were consistently found in the rising phase due to the concentric nature/demands during the rising half. There is significant evidence suggesting that EMG activity was greater during concentric activation compared to eccentric activation [1,21,22]. More specifically, qualitative analysis led us to believe that the peak occurred during the knee ascent phase (lead limb) and knee extension phase (stationary limb). During the knee ascent and knee extension phases, the lead and stationary limb RF and stationary GMax were working concentrically against gravity to generate extensor torque to raise the center of mass and bring the body to an upright position. It is unclear why the stationary GMed and BF demonstrated peak muscle activation consistently in the rising half compared to the lowering half. Additionally, the peak muscle activity of the lead BF, GMed, and GMax did not consistently occur in either the rising or lowering half of the lunge. This is likely due to individual liberties and variability with the reverse lunge, especially during the backswing phase.  
[PERSON] et al. studied the effects of resistance duration during unilateral knee extension exercises on strength gains and muscle hypertrophy of the RF and vastus lateralis muscles [23]. They reported increased gains in MVIC when resistance duration was increased [23]. Since the peak percent of MVIC is a single point in time, there is limited resistance duration. Utilizing the peak percent of MVIC may be important in determining at which phase of the reverse lunge the peak occurred. The clinician may use that information to emphasize muscle activation during that phase (or a portion of that phase) by increasing the duration or load. While we did not quantitatively determine exactly when or during which phase peak muscle activity occurred, we qualitatively determined by visual analysis of the RMS analysis whether the peak occurred in the rising or lowering half. Thus, the phase where the peak occurred can be loosely inferred.