# The Reverse Lunge: A Descriptive Electromyographic Study
## 4 Discussion
### Clinical Implications  
The reverse lunge movement is a widely and commonly used exercise in physical rehabilitation practices. Rationalizing the purpose for prescribed exercise is critical [24]. Since the reverse lunge can be used for many pathologies and conditions, it is important to consider a few examples. Clinically, it is important to understand a patient's injury or condition to determine their ability to execute this movement safely. For example, a patient after a muscle strain injury (such as a rectus femoris or biceps femoris strain) may have unique LE considerations, and the clinician can intentionally choose a limb to act as the lead limb or stationary limb. When the involved limb acts as the stationary limb there will be increased strength demands of the RF and BF. Since there is increased muscular force required by the lead limb, clinicians should avoid using the involved limb as the lead limb until appropriate muscle healing, and neuromuscular control exists to perform the movement. In another example, after hip arthroscopy or arthroplasty, a patient may present with impaired frontal plane pelvic stability and GMed weakness [25]. In addition to standard isolated rehabilitation exercises, the reverse lunge may be used to impact not only strength, but stability, balance, and motor control. This study's results suggest that designating the involved limb as the stationary limb would best target strengthening for the involved side GMed, while using the involved limb as the lead limb may only be effective at enhancing endurance for the involved side GMed. Compared to the forward lunge, the reverse lunge has been demonstrated to invoke decreased patellofemoral (PF) joint compressive forces due to the smaller angle of knee flexion on the lead limb [7]. The results of the current study revealed that the RF, which is a primary knee extensor and eccentric controller of knee flexion, was activated to a low-level (stability/endurance) stimulus in the stationary limb and a high-level (strengthening) stimulus in the lead limb. If a patient is experiencing pain at the PF joint, designating the involved limb as the stationary limb while performing the reverse lunge (compared to the involved limb as the lead limb) may decrease the force required by the muscles. This would result in decreased contact stresses at the PF joint and allow for stability and endurance training. However, in the absence of PF pain, the RF is activated to a greater extent in the lead limb compared to the stationary limb, and it is more likely to produce strength gains. It is difficult to make direct comparisons with the existing literature due to the limited studies available on the reverse lunge EMG. However, we can make loose comparisonsof the overall activation of key LE musculature between similar movements. A study by [PERSON] et al. investigating the activation of muscles during the split squat showed similar peak muscle activation for the BF (19%), RF (38-40%), and GMed (25%) of the forward leg in the split squat, which correlates to the stationary limb in the reverse lunge [26]. The GMed activation of the stationary limb during the reverse lunge (49.2%) was greater than that found in the study by [PERSON] et al. and was likely due to the demands placed on the muscle in single limb stance [26]. [PERSON] et al. [6] found the GMed muscle activation of the moving limb during the bodyweight lateral lunge to be 39%. Although the lateral lunge is a frontal plane movement, the GMed activation was similar to the current results in the reverse lunge lead limb (34.29%). When comparing the reverse lunge to similar loaded movements, one study by [PERSON] et al. assessed a weighted barbell forward lunge and found that of all LE muscles assessed (GMed, GMax, BF, RF, vastus lateralis, and vastus medialis), the RF was consistently the most active [1]. Loose inferences can be made that, in both loaded and unloaded lungs, the RF would be the most activated.