Shod versus barefoot effects on force and power development during a conventional deadlift
Hammer, ME, Meir, RA, Whitting, JW & Crowley-McHattan, ZJ in press, 'Shod versus barefoot effects on force and power development during a conventional deadlift', The Journal of Strength and Conditioning Research.
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The kinetics of a conventional deadlift in shod (S) versus unshod (US) footwear conditions in 10 male participants (mean +/- SD, age = 27.0 +/- 5.8 years; weight = 78.7 +/- 11.5 kg; height = 175.8 +/- 8.2 cm; 1RM deadlift = 155.8 +/- 25.8 kg) was assessed in two testing sessions. A counterbalanced, crossover experimental design was used with different loads (60% and 80% 1RM). Four sets of four repetitions were prescribed per session with two sets per shoe and with each shoe condition involving one set per load. Peak vertical force (PF), rate of force development (RFD), time to peak force (TPF), anterior-posterior (COP-AP) and medio-lateral (COP-ML) center of pressure excursion, and barbell peak power (PP) data were recorded during all repetitions. Except for RFD (F = 6.389; p = 0.045; [eta]p2 = 0.516) and ML-COP (F = 6.696; p = 0.041; [eta]p2 = 0.527), there were no other significant main effects of shoe. There were significant main effects of load for PF (p < 0.05), COP-AP (p = 0.011), TPF (p = 0.018) and COP-AP (p = 0.011). There were no significant interactions found between session, shoe and load (p range from 0.944 to 0.086). While the unshod condition may have produced changes in RFD and ML-COP compared with the shod condition, there is only limited evidence in the current study to support this lifting technique for the conventional deadlift. Further investigation is required to clarify any possible implications of this result and its benefit to lifters.