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The influence of muscle activation on impact dynamics during lateral falls on the hip
- Source :
- Journal of Biomechanics. 66:111-118
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- Muscle activation has been demonstrated to influence impact dynamics during scenarios including running, automotive impacts, and head impacts. This study investigated the effects of targeted muscle activation magnitude on impact dynamics during low energy falls on the hip with human volunteers. Fifteen university-aged participants (eight females, seven males) underwent 12 lateral pelvis release trials. Half of the trials were muscle-'relaxed'; in the remaining 'contracted' trials participants isometrically contracted their gluteus medius to 20-30% of maximal voluntary contraction before the drop was initiated onto a force plate. Peak force applied to the femur-pelvis complex averaged 9.3% higher in contracted compared to relaxed trials (F = 6.798, p = .022). Muscle activation effects were greater for females, resulting in (on average) an 18.5% increase in effective pelvic stiffness (F = 5.838, p = .046) and a 23.4% decrease in time-to-peak-force (F = 5.109, p = .042). In the relaxed trials, muscle activation naturally increased during the impact event, reaching levels of 12.8, 7.5, 11.1, and 19.1% MVC at the time of peak force for the gluteus medias, vastus lateralis, erector spinae, and external oblique, respectively. These findings demonstrated that contraction of trunk and hip musculature increased peak impact force across sexes. In females, increases in the magnitude and rate of loading were accompanied (and likely driven) by increases in system stiffness. Accordingly, incorporating muscle activation contributions into biomechanical models that investigate loading dynamics in the femur and/or pelvis during lateral impacts may improve estimate accuracy.
- Subjects :
- Adult
Male
medicine.medical_specialty
Contraction (grammar)
Adolescent
0206 medical engineering
Biomedical Engineering
Biophysics
02 engineering and technology
Pelvis
Young Adult
03 medical and health sciences
0302 clinical medicine
Internal medicine
medicine
Humans
Orthopedics and Sports Medicine
Femur
Muscle, Skeletal
Impact dynamics
Hip fracture
Hip
biology
business.industry
Rehabilitation
Muscle activation
Anatomy
medicine.disease
biology.organism_classification
020601 biomedical engineering
Trunk
Biomechanical Phenomena
Medius
medicine.anatomical_structure
Cardiology
Accidental Falls
Female
business
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 00219290
- Volume :
- 66
- Database :
- OpenAIRE
- Journal :
- Journal of Biomechanics
- Accession number :
- edsair.doi.dedup.....e8e106b784d4999c4c088a33e7d7e241