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Hamstring injury prevention in soccer: Before or after training?
Author(s) -
Lovell R.,
Knox M.,
Weston M.,
Siegler J. C.,
Brennan S.,
Marshall P. W. M.
Publication year - 2018
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12925
Subject(s) - hamstring , eccentric , biceps , medicine , hamstring injury , muscle architecture , electromyography , physical therapy , football players , confidence interval , concentric , physical medicine and rehabilitation , football , anatomy , poison control , mathematics , injury prevention , physics , geometry , environmental health , quantum mechanics , political science , law
We examined the effects of a 12‐week program of Nordic hamstring exercises ( NHE ), administered before or after football training, upon eccentric hamstring strength, muscle activity, and architectural adaptations. Amateur soccer players were randomized into three groups. The control group ( CON ; n=11) undertook core stability exercises, whereas a periodized NHE program was delivered either before ( NHE BEF ; n=10) or after ( NHE AFT ; n=14) biweekly training sessions. Outcome measures included peak torque and concomitant normalized peak surface electromyography signals ( sEMG ) of the biceps femoris ( BF ) and medial hamstring ( MH ) muscles during knee flexor maximal eccentric contractions, performed at 30°·s −1 . Ultrasonography was used to determine BF muscle thickness, muscle fiber pennation angle, and fascicle length. Performing the NHE derived likely moderate peak torque increases in both NHE BEF (+11.9%; 90% confidence interval: 3.6%‐20.9%) and NHE AFT (+11.6%; 2.6%‐21.5%) vs CON . Maximum sEMG increases were moderately greater in the BF of both NHE training groups vs CON . There were likely moderate increases in BF muscle thickness (+0.17 cm; 0.05‐0.29 cm) and likely small pennation angle increases (+1.03°; −0.08° to 2.14°) in NHE AFT vs CON and NHE BEF . BF fascicle length increases were likely greater in NHE BEF (+1.58 cm; 0.48‐2.68 cm; small effect) vs CON and NHE AFT . A 12‐week eccentric hamstring strengthening program increased strength and sEMG to a similar magnitude irrespective of its scheduling relative to the football training session. However, architectural adaptations to support the strength gains differed according to the timing of the injury prevention program.