TY - JOUR

T1 - Alterations in neuromuscular function in girls with generalized joint hypermobility

AU - Jensen, Bente Rona

AU - Melcher, Jesper Sandfeld

AU - Melcher, Pia Grethe Sandfeld

AU - Johansen, Katrine Lyders

AU - Hendriksen, Peter

AU - Juul-Kristensen, Birgit

N1 - CURIS 2016 NEXS 298

PY - 2016

Y1 - 2016

N2 - Background: Generalized Joint Hypermobility (GJH) is associated with increased risk of musculoskeletal joint pain. We investigated neuromuscular performance and muscle activation strategy.Methods: Girls with GJH and non-GJH (NGJH) performed isometric knee flexions (90°,110°,130°), and extensions (90°) at 20 % Maximum Voluntary Contraction, and explosive isometric knee flexions while sitting. EMG was recorded from knee flexor and extensor muscles.Results: Early rate of torque development was 53 % faster for GJH. Reduced hamstring muscle activation in girls with GJH was found while knee extensor and calf muscle activation did not differ between groups. Flexion-extension and medial-lateral co-activation ratio during flexions were higher for girls with GJH than NGJH girls.Conclusions: Girls with GJH had higher capacity to rapidly generate force than NGJH girls which may reflect motor adaptation to compensate for hypermobility. Higher medial muscle activation indicated higher levels of medial knee joint compression in girls with GJH. Increased flexion-extension co-activation ratios in GJH were explained by decreased agonist drive to the hamstrings.

AB - Background: Generalized Joint Hypermobility (GJH) is associated with increased risk of musculoskeletal joint pain. We investigated neuromuscular performance and muscle activation strategy.Methods: Girls with GJH and non-GJH (NGJH) performed isometric knee flexions (90°,110°,130°), and extensions (90°) at 20 % Maximum Voluntary Contraction, and explosive isometric knee flexions while sitting. EMG was recorded from knee flexor and extensor muscles.Results: Early rate of torque development was 53 % faster for GJH. Reduced hamstring muscle activation in girls with GJH was found while knee extensor and calf muscle activation did not differ between groups. Flexion-extension and medial-lateral co-activation ratio during flexions were higher for girls with GJH than NGJH girls.Conclusions: Girls with GJH had higher capacity to rapidly generate force than NGJH girls which may reflect motor adaptation to compensate for hypermobility. Higher medial muscle activation indicated higher levels of medial knee joint compression in girls with GJH. Increased flexion-extension co-activation ratios in GJH were explained by decreased agonist drive to the hamstrings.

KW - Faculty of Science

KW - Hypermobile

KW - Knee

KW - EMG

KW - Muscle activation

KW - Rate of force development

U2 - 10.1186/s12891-016-1267-5

DO - 10.1186/s12891-016-1267-5

M3 - Journal article

C2 - 27716255

VL - 17

JO - B M C Musculoskeletal Disorders

JF - B M C Musculoskeletal Disorders

SN - 1471-2474

M1 - 410

ER -