(7) COMPARISON OF HORIZONTAL BARBELL DISPLACEMENT BETWEEN TRADITIONAL AND FLYWHEEL INERTIAL SQUATS

Purpose: The purpose of this study was to compare the horizontal barbell displacement between traditional back squats and flywheel inertial (FW) squats. Methods: This study included 26 resistance-trained individuals including fourteen men (age = 23.7 ± 3.7 years, height = 174.3 ± 7.9 cm, body mass = 81.4 ± 12.7 kg, relative one repetition maximum [1RM] back squat = 2.03 ± 0.35 kg/kg) and twelve women (age = 22.8 ± 1.8 years, height = 165.5 ± 8.3 cm, body mass = 71.3 ± 7.7 kg, relative 1RM back squat = 1.45 ± 0.23 kg/kg). Each subject participated in three separate testing sessions that required them to complete a 1RM back squat protocol in the first session and then either traditional back squat or FW squat sets in the final two sessions. The traditional back squat testing required the subjects to perform sets of three repetitions using 40, 50, 60, 70, and 80% of their 1RM back squat. In contrast, subjects performed five FW squats using 0.01, 0.025, 0.050, 0.075, and 0.10 kgm2 inertial wheels during the other testing session. It should be noted that only the last three repetitions of each FW set were analyzed for statistical analysis. Each squat repetition was performed with a GymAware linear position transducer attached to the barbell or PVC pipe for the traditional and FW squats, respectively. The maximum horizontal displacement of each repetition was recorded and the average across each set was used for statistical comparison. A 2 (condition) x 5 (load) repeated measures ANOVA test was used to examine the differences between squat conditions performed with a spectrum of loads. In addition, Hedge’s g effect sizes were used to examine the magnitude of the differences between squat conditions and loads. Results: There was a significant condition x load interaction effect for horizontal displacement (p < 0.001). Descriptive data and post hoc comparisons between conditions at each load are shown in Table 1. The differences in horizontal displacement between traditional and FW squats at each load were large in magnitude (g = 1.23-1.74). Conclusions: Greater barbell horizontal displacement occurred during the FW squats when compared to the traditional back squats at every load. Horizontal displacement was consistent across loads for both traditional and FW squats. Practical Applications: Strength and conditioning practitioners interested in prescribing FW squats should be aware of a potential increase in horizontal displacement compared to traditional squats, especially at heavier loads. An increased horizontal displacement may impact the ability of an individual to apply vertical force in an effective manner. Further research is needed to determine if long-term exposure to traditional or FW squats impacts the transfer of training effects to various athletic tasks. Acknowledgements: None