Abstract
PURPOSE: The purpose of this study was to assess the differences in muscle activation, range of motion, and “ease of use” between the conventional barbell hip thrust (FW), and the machine counterpart (M).
METHODS: 28 (age: 20.8 ± 1.4 yr., ht. 171.2 ± 8.6 cm., wt. 70.6 ± 12.0 kg.) apparently healthy individuals with ≥1 yr. of resistance training experience volunteered to participate. Participants were tested on 2 days. Day 1- familiarization, followed by, randomized, 10RM testing of both FW and M, while measuring range of motion (ROM) of the knee with the use of an electronic goniometer. Day 2- Surface EMG testing of the Gluteus Maximus (GM), Biceps Femoris (BF) and Vastus Lateralis (VL) was conducted utilizing the previously titrated 10RMs for FW and M. An MVIC was performed for GM, BF, and VL, which was followed by one set of the pre-determined 10RM for both the FW and M in a randomized fashion. Surface EMG electrodes were placed on the aforementioned muscles consistent with SENIAM guidelines. Following completion, each participant filled out a questionnaire regarding perceived performance. Statistical analysis by paired t-test was applied to the data (p < .05).
RESULTS: Significant differences were evident between EMG mean amplitude for BF in M vs FW (78.7% vs. 65.5%) and EMG mean amplitude for VL in FW vs M (42.5% vs. 37.8%). While mean (67.0% vs 66.5%) and max (151.5% vs. 147.1%) amplitudes for GM were similar between M and FW. Knee flexion ROM was significantly greater in FW vs M at both the bottom and top of the movement, 95.6 ± 9.6 degrees and 74.7 ± 6.7 degrees, 88.1 ± 3.3 and 83.3 ± 5.5 (p < .001), respectively. Qualitative questionnaire assessment indicated the following: Regarding ease of performance, M was preferred over (53.6%) over FW (46.4%). Participants indicated they would include M (53.6%) in their training program over FW (42.9%). Participants would recommend M (92.9%) over FW (7.1%) for an untrained individual.
CONCLUSION: Both M and FW elicited similar GM activation, however participants preferred performing the hip thrust on the M as opposed to the traditional FW version of the exercise. M elicited significantly greater BF mean activation, and significantly less VL activation. This could be attributed to differences in knee flexion ROM between M and FW. Supported, in part by BootyBuilder.