Advanced Search

Home > Journals > The Journal of Sports Medicine and Physical Fitness > Past Issues > The Journal of Sports Medicine and Physical Fitness 2015 June;55(6) > The Journal of Sports Medicine and Physical Fitness 2015 June;55(6):587-95

ISSUES AND ARTICLES   MOST READ   eTOC

CURRENT ISSUETHE JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS

A Journal on Applied Physiology, Biomechanics, Preventive Medicine,
Sports Medicine and Traumatology, Sports Psychology

Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,111

Frequency: Monthly

ISSN 0022-4707

Online ISSN 1827-1928

 

The Journal of Sports Medicine and Physical Fitness 2015 June;55(6):587-95

EXERCISE PHYSIOLOGY 

    ORIGINAL ARTICLES

Comparison of stretch reflex responses evoked during drop jumping in highly skilled atheles versus untrained subjects

Judge L. W. 1, Burke J. R. 2

1 School of Kinesiology, Ball State University Muncie, IN, USA;
2 Research Department, New York Chiropractic College, Seneca Falls, NY, USA

AIM: The purpose of the study was to describe changes in the excitability of the stretch reflex response (SRR) during different drop jumps as a function of training background and as an adaptation to a preseason sport-specific resistance training program.
METHODS: Twelve collegiate field event athletes (discus, hammer, javelin, shot put, and weight; 9 males and 3 females) and 12 college-aged control subjects performed the following three jumps: 1) countermovement jump (CMJ); 2) countermovement drop jump; and 3) bounce-drop jump (BDJ). Neuromechanical changes in the performance of drop jumps by athletes were measured during the sport-specific resistance training program. Pre-post testing of drop jump performance by control subjects was included for comparison. For each jump trial, ground reaction forces (GRF), electromyograms (EMG) and cinematographic data were collected.
RESULTS: There were no training adaptations. However, jump heights were greater for the athletes than the controls among the different jumps with the jump heights for all subjects being less during the BDJ than CMJ and CDJ. In athletes only, there was a differential modulation of the SRR from the gastrocnemius muscle with different levels of background muscle activity for the CDJ and BDJ.
CONCLUSION: There were changes in excitability of SRR from the gastrocnemius muscle as a function of training background. Interrelated neuromechanical mechanisms to include landing biomechanics, intrinsic musculotendinous tissue properties of the ankle, and centrally regulated motor commands may underlie the facilitation of the SRR from the gastrocnemius muscle in athletes as compared to controls.

language: English


FULL TEXT  REPRINTS

top of page