title: Unilateral plantar flexors static-stretching effects on ipsilateral and contralateral jump measures.
abstract: The aim of this study was to evaluate the acute effects of unilateral ankle plantar flexors static-stretching (SS) on the passive range of movement (ROM) of the stretched limb, surface electromyography (sEMG) and single-leg bounce drop jump (SBDJ) performance measures of the ipsilateral stretched and contralateral non-stretched lower limbs. Seventeen young men (24 ± 5 years) performed SBDJ before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) unilateral ankle plantar flexor SS (6 sets of 45s/15s, 70-90% point of discomfort). SBDJ performance measures included jump height, impulse, time to reach peak force, contact time as well as the sEMG integral (IEMG) and pre-activation (IEMGpre-activation) of the gastrocnemius lateralis. Ankle dorsiflexion passive ROM increased in the stretched limb after the SS (pre-test: 21 ± 4° and post-test: 26.5 ± 5°, p < 0.001). Post-stretching decreases were observed with peak force (p = 0.029), IEMG (P<0.001), and IEMGpre-activation (p = 0.015) in the stretched limb; as well as impulse (p = 0.03), and jump height (p = 0.032) in the non-stretched limb. In conclusion, SS effectively increased passive ankle ROM of the stretched limb, and transiently (less than 10 minutes) decreased muscle peak force and pre-activation. The decrease of jump height and impulse for the non-stretched limb suggests a SS-induced central nervous system inhibitory effect. Key pointsWhen considering whether or not to SS prior to athletic activities, one must consider the potential positive effects of increased ankle dorsiflexion motion with the potential deleterious effects of power and muscle activity during a simple jumping task or as part of the rehabilitation process.Since decreased jump performance measures can persist for 10 minutes in the stretched leg, the timing of SS prior to performance must be taken into consideration.Athletes, fitness enthusiasts and therapists should also keep in mind that SS one limb has generalized effects upon contralateral limbs as well.
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil.
authors.forename: Josinaldo Jarbas
authors.initials: JJ
authors.lastname: da Silva
authors.affiliation: School of Human Kinetics and Recreation, Memorial University of Newfoundland , Canada.
authors.forename: David George
authors.initials: DG
authors.lastname: Behm
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil.
authors.forename: Willy Andrade
authors.initials: WA
authors.lastname: Gomes
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil.
authors.forename: Fernando Henrique Domingues de Oliveira
authors.initials: FH
authors.lastname: Silva
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil.
authors.forename: Enrico Gori
authors.initials: EG
authors.lastname: Soares
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil.
authors.forename: Érica Paes
authors.initials: ÉP
authors.lastname: Serpa
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil.
authors.forename: Guanis de Barros
authors.initials: Gde B
authors.lastname: Vilela Junior
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil ; Faculty Adventist of Hortolândia (UNASP), Hortolândia , São Paulo, Brazil.
authors.forename: Charles Ricardo
authors.initials: CR
authors.lastname: Lopes
authors.affiliation: Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba , Piracicaba, São Paulo, Brazil ; Institute of Orthopedics and Traumatology, School of Medicine, University of São Paulo , Laboratory of Kinesiology, São Paulo, Brazil.
authors.forename: Paulo Henrique
authors.initials: PH
authors.lastname: Marchetti
keywords: Athletic training; cross-education; crossover; exercise performance; exercise training