Influence of Whole Body Vibration and Specific Warm-ups on Force during an Isometric Mid-Thigh Pull

Abstract

Purpose: The purpose of this study was to investigate the effects of general and specific warm-up protocols on rate of force development (RFD), relative RFD (rRFD), ground reaction force (GRF) and relative ground reaction force (rGRF) during an isometric mid-thigh pull (IMTP), after WBV exposure. Methods: Fifteen healthy recreationally trained males (age: 24.1 ± 2.3 yrs, height: 72.9 ± 7.8 cm; mass: 86.9 ± 8.3) completed five protocols: baseline, isometric vibration (iVib), isometric no vibration (iNV), dynamic vibration (dVib) and dynamic no vibration (dNV). The baseline was completed without any warm-up prior to the IMTP. The intervention protocols had the same prescription of 4 sets of 30-second bouts of quarter squats (dynamic [DQS] and isometric [IQS]) on the WBV platform with or without vibration. Following a one-minute rest period after each protocol, participants completed three maximal IMTPs. Results: Repeated measures ANOVA with a Bonferroni post hoc demonstrated that RFD in dNV (7657.8 ± 2292.5 N/s) was significantly greater than iVib (7156.4 ± 2170.0 N/s). However, the other experimental trials for RFD demonstrated no significant differences (p>0.05). There were also no significant differences for rRFD, GRF or rGRF between protocols. Conclusion: These results demonstrate that a dynamic warm-up without WBV elicits greater RFD than an isometric warm-up with WBV prior to a maximal isometric exercise. Further research needs to be investigated utilizing dynamic and isometric warm-ups in conjunction with WBV and power output.

Influences of Athletic Footwear on Ground Reaction Forces During A Sidestep Cutting Maneuver on Artificial Turf

“…Experimental Setup looked at the time from initial foot contact (defined as when force increased 1N above body weight) to peak brake, while the propulsion phase was estimated from the time it took from the peak brake time to the peak propulsion time. RFD was determined by the amount of force produced over the change in time within each direction and phase of the SCM (Cazás- Moreno et al, 2015;Haff, Ruben, Lider, Twine, & Cormie, 2015). All kinetic data were normalized to each participant's body weight (N) to allow for comparative analysis.…”

“…Participants were tested in all three types of footwear (FB, SOC, RUN) with the order determined by a counterbalanced design. All participants completed a dynamic warm-up (Cazás-Moreno et al, 2015) with additional self-directed stretching of the trunk and lower extermity, if desired. Upon conclusion of the warm-up and prior to testing in each footwear, participants were allowed as many warmup repetitions of the SCM as necessary.…”