DIFFERENCES IN MAXIMAL FORCE PRODUCTION OF THE SQUAT AND KNEE EXTENSION WITH DIFFERENT VERBAL COMMANDS
Micheal Luera, Jesus Hernandez-Sarabia, Carlos Estrada, Tyler Muddle, Jason DeFreitas,
Oklahoma State University, Stillwater, OK
It is suggested that verbal commands influence the ability to produce peak force during maximal voluntary isometric contractions (MVC). When determining peak force capabilities during MVC it is recommended to use the verbal command, as “hard” as possible. Additionally, when instructing conditions to achieve maximal rate of force development (RFD), using the verbal command as “fast” as possible. PURPOSE: To examine the influence of two different verbal commands on peak force production during MVC’s performed during the squat (SQ) and knee extension (KE) exercises. METHODS: Twenty-five lower-body resistance trained males (n = 16, mean ± SD; 24 ± 3 yrs; 88.08 ± 11.09 kg; 175 ± 7 cm) and females (n = 9, 23 ± 4 yrs; 62.53 ± 6.84 kg; 164 ± 7 cm) performed two separate MVC during both SQ and KE exercises. Knee joint angles were set at 110° during both exercise conditions, and hip angle was ~110° during SQ and ~105° during KE. During both exercise conditions, peak force (N) was measured using an S-beam load cell. Throughout both exercise conditions, subjects performed MVCs under two different verbal command to; 1.) determine maximal force capabilities, subject were verbal instructed to push as “hard” as possible, and 2.) determine maximal RFD capabilities, subjects were instructed to push as “quick” as possible. RESULTS: One-way repeated measures analysis of variance indicated that, when instructed to push as “quick” as possible compared to as “hard” as possible, peak force was significantly higher during both the SQ (mean ± SE; 2258.11 ± 131.01 N vs 2094.33 ± 123.58 N) and KE (785.90 ± 49.03 N vs 757.45 ± 47.04 N) conditions (P< 0.05). CONCLUSION: Contrary to previous recommendations, these findings indicate that during isometric SQ and KE exercises, performed at the same knee joint angle, peak force is greater when specifically instructed to produce maximal force MVCs as “quick” as possible vs as “hard” as possible.
Luera, M; Hernandez-Sarabia, J; Estrada, C; Muddle, T; and DeFreitas, J
"DIFFERENCES IN MAXIMAL FORCE PRODUCTION OF THE SQUAT AND KNEE EXTENSION WITH DIFFERENT VERBAL COMMANDS,"
International Journal of Exercise Science: Conference Proceedings: Vol. 11:
6, Article 45.
Available at: https://digitalcommons.wku.edu/ijesab/vol11/iss6/45