EMG Activity With Use of a Hands-Free Single Crutch vs a Knee Scooter

Abstract

Background: Foot and ankle injuries frequently require a period of nonweightbearing, resulting in muscle atrophy. Our previous study compared a hands-free single crutch (HFSC) to standard axillary crutches and found increased muscle recruitment and intensity while using the HFSC. Knee scooters are another commonly prescribed nonweightbearing device. The purpose of this study is to examine the electromyographic (EMG) differences between an HFSC and knee scooter, in conjunction with device preference and perceived exertion. Methods: A randomized crossover study was performed using 30 noninjured young adults. Wireless surface EMG electrodes were placed on the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and gluteus maximus (GM). Participants then ambulated along a 20-m walking area while 15 seconds of the gait cycle was recorded across 3 conditions: walking with a knee scooter, an HFSC, and with no assistive device. Mean muscle activity and peak EMG activity were recorded for each ambulatory modality. Immediately following testing, patient exertion and device preference was recorded. Results: The RF, LG, and GM showed increased peak EMG activity percentage, and the LG showed increased mean muscle activity while using the HFSC compared with the knee scooter. When comparing the knee scooter and HFSC to walking, both showed increased muscle activity in the RF, VL, and LG but no difference in the GM. There was no statistical difference in participant preference, whereas the HFSC had a statistically significant higher perceived exertion than the knee scooter ( P < .001). Conclusion: In this group of young, healthy noninjured volunteers, the HFSC demonstrated increased peak EMG activity in most muscle groups tested compared with the knee scooter. Level of Evidence: Level II, prospective comparative study.

Hands-Free Crutch Reduces The Muscle Atrophy Attributed to Non-Weight Bearing Injuries

“…A similar result was found when a subsequent study was performed this time comparing the muscle activity for the HFC with a knee scooter (Dewar et al, 2021). This study demonstrated a statistically significant increase in muscle recruitment while maintaining in phase muscle activation patterns consistent with normal walking when using the HFC compared to a knee scooter.…”

“…Prior research shows that the HFC, crutches and knee scooters exhibit statistically significant differences in muscle activation for the lower extremities (Sanders et al, 2018;Dewar and Martin, 2020;Dewar et al, 2021;Clark et al, 2004;Seynnes et al, 2008). This is illustrated in Fig.…”

Popliteal Blood Flow With Lower-Extremity Injury Mobility Devices

“…The effect of knee flexion in HFC was likely mitigated by its unique ambulation similar to walking gait, given that muscular activity is a major determinant of popliteal venous flow, and previously mentioned evidence demonstrates elevated surface electromyography when using HFC. 7 , 19 The use of HFC may be a better option than MKS in populations requiring foot/ankle unloading where venous pooling is of concern, such as those at risk for DVT.…”

“…19 HFC use elevates muscle activation in the rectus femoris, vastus lateralis, and lateral gastrocnemius compared with AC and MKS. 7,8 Although not directly shown, these data may provide indirect evidence of the potential to mitigate atrophy and strength loss in specific muscle groups over the duration of an unloading period.…”

“… 2 Given HFC simulates regular gait and requires weightbearing through the gait cycle, we hypothesized this would enhance muscle pump activity and affect local blood flow and vessel dimensions. 7 , 8 Thus, the aim of this research was to investigate blood flow and vessel dimensions at rest (baseline) and immediately following an ambulation simulation involving regular walking, MKS, AC, and HFC.…”