Jacob D Jelmini1, Andrew Cornwell2, Nazareth Khodiguian2, Jennifer Thayer2, And John Araujo2. 1. School of Kinesiology and Nutritional Science, California State University, Los Angeles, CA, 90032, USA. jjelmin2@calstatela.edu. 2. School of Kinesiology and Nutritional Science, California State University, Los Angeles, CA, 90032, USA.
Abstract
PURPOSE: To determine the effects of an acute bout of unilateral static stretching on handgrip strength of both the stretched and non-stretched limb. It was reasoned that if the non-stretched limb experienced a decrease in force output, further evidence for a neural mechanism to explain a post-stretch force reduction would be obtained as no mechanical adaptation would have occurred. METHODS: Thirty participants performed maximum voluntary unilateral handgrip contractions of both limbs before and after stretching the finger flexors of the strength-dominant side only. Each trial was assessed for peak force, muscle activity (iEMG), and rate of force generation. RESULTS: Following the stretching bout, peak force and iEMG decreased by 4.4% (p = 0.001) and 6.4% (p = 0.000) respectively in the stretched limb only. However, rate of force generation was significantly impaired in both the stretched (- 17.3%; p = 0.000) and non-stretched limbs (- 10.8%; p = 0.003) 1 min post-stretch, and remained similarly depressed for both limbs 15 min later. CONCLUSION: Acute stretching negatively impacts rate of force generation more than peak force. Moreover, a reduced rate of force generation from the non-stretched limb indicates the presence of a cross-over inhibitory effect through the nervous system, which provides additional evidence for a neural mechanism.
PURPOSE: To determine the effects of an acute bout of unilateral static stretching on handgrip strength of both the stretched and non-stretched limb. It was reasoned that if the non-stretched limb experienced a decrease in force output, further evidence for a neural mechanism to explain a post-stretch force reduction would be obtained as no mechanical adaptation would have occurred. METHODS: Thirty participants performed maximum voluntary unilateral handgrip contractions of both limbs before and after stretching the finger flexors of the strength-dominant side only. Each trial was assessed for peak force, muscle activity (iEMG), and rate of force generation. RESULTS: Following the stretching bout, peak force and iEMG decreased by 4.4% (p = 0.001) and 6.4% (p = 0.000) respectively in the stretched limb only. However, rate of force generation was significantly impaired in both the stretched (- 17.3%; p = 0.000) and non-stretched limbs (- 10.8%; p = 0.003) 1 min post-stretch, and remained similarly depressed for both limbs 15 min later. CONCLUSION: Acute stretching negatively impacts rate of force generation more than peak force. Moreover, a reduced rate of force generation from the non-stretched limb indicates the presence of a cross-over inhibitory effect through the nervous system, which provides additional evidence for a neural mechanism.
Entities:
Keywords:
Force impairment; Neural inhibition; Static stretching
Authors: Josinaldo Jarbas da Silva; David George Behm; Willy Andrade Gomes; Fernando Henrique Domingues de Oliveira Silva; Enrico Gori Soares; Érica Paes Serpa; Guanis de Barros Vilela Junior; Charles Ricardo Lopes; Paulo Henrique Marchetti Journal: J Sports Sci Med Date: 2015-05-08 Impact factor: 2.988