Isometric and isokinetic hip strength and agonist/antagonist ratios in symptomatic femoroacetabular impingement

Diamond, Laura E., Wrigley, Tim V., Hinman, Rana S., Hodges, Paul W., O'Donnell, John, Takla, Amir and Bennell, Kim L. (2015) Isometric and isokinetic hip strength and agonist/antagonist ratios in symptomatic femoroacetabular impingement. Journal of Science and Medicine in Sport, 19 9: 696-701. doi:10.1016/j.jsams.2015.10.002


Author Diamond, Laura E.
Wrigley, Tim V.
Hinman, Rana S.
Hodges, Paul W.
O'Donnell, John
Takla, Amir
Bennell, Kim L.
Title Isometric and isokinetic hip strength and agonist/antagonist ratios in symptomatic femoroacetabular impingement
Journal name Journal of Science and Medicine in Sport   Check publisher's open access policy
ISSN 1878-1861
1440-2440
Publication date 2015-06-30
Year available 2015
Sub-type Article (original research)
DOI 10.1016/j.jsams.2015.10.002
Open Access Status Not yet assessed
Volume 19
Issue 9
Start page 696
End page 701
Total pages 6
Place of publication Chatswood, NSW, Australia
Publisher Elsevier
Language eng
Subject 2732 Orthopedics and Sports Medicine
3612 Physical Therapy, Sports Therapy and Rehabilitation
Abstract Objectives This study investigated isometric and isokinetic hip strength in individuals with and without symptomatic femoroacetabular impingement (FAI). The specific aims were to: (i) determine whether differences exist in isometric and isokinetic hip strength measures between groups; (ii) compare hip strength agonist/antagonist ratios between groups; and (iii) examine relationships between hip strength and self-reported measures of either hip pain or function in those with FAI. Design Cross-sectional. Methods Fifteen individuals (11 males; 25 ± 5 years) with symptomatic FAI (clinical examination and imaging (alpha angle >55° (cam FAI), and lateral centre edge angle >39° and/or positive crossover sign (combined FAI))) and 14 age- and sex-matched disease-free controls (no morphological FAI on magnetic resonance imaging) underwent strength testing. Maximal voluntary isometric contraction strength of hip muscle groups and isokinetic hip internal (IR) and external rotation (ER) strength (20°/s) were measured. Groups were compared with independent t-tests and Mann–Whitney U tests. Results Participants with FAI had 20% lower isometric abduction strength than controls (p = 0.04). There were no significant differences in isometric strength for other muscle groups or peak isokinetic ER or IR strength. The ratio of isometric, but not isokinetic, ER/IR strength was significantly higher in the FAI group (p = 0.01). There were no differences in ratios for other muscle groups. Angle of peak IR torque was the only feature correlated with symptoms. Conclusions Individuals with symptomatic FAI demonstrate isometric hip abductor muscle weakness and strength imbalance in the hip rotators. Strength measurement, including agonist/antagonist ratios, may be relevant for clinical management of FAI.
Formatted abstract
Objectives: This study investigated isometric and isokinetic hip strength in individuals with and without symptomatic femoroacetabular impingement (FAI). The specific aims were to: (i) determine whether differences exist in isometric and isokinetic hip strength measures between groups; (ii) compare hip strength agonist/antagonist ratios between groups; and (iii) examine relationships between hip strength and self-reported measures of either hip pain or function in those with FAI.

Design: Cross-sectional.

Methods: Fifteen individuals (11 males; 25 ± 5 years) with symptomatic FAI (clinical examination and imaging (alpha angle >55° (cam FAI), and lateral centre edge angle >39° and/or positive crossover sign (combined FAI))) and 14 age- and sex-matched disease-free controls (no morphological FAI on magnetic resonance imaging) underwent strength testing. Maximal voluntary isometric contraction strength of hip muscle groups and isokinetic hip internal (IR) and external rotation (ER) strength (20°/s) were measured. Groups were compared with independent t-tests and Mann–Whitney U tests.

Results: Participants with FAI had 20% lower isometric abduction strength than controls (p = 0.04). There were no significant differences in isometric strength for other muscle groups or peak isokinetic ER or IR strength. The ratio of isometric, but not isokinetic, ER/IR strength was significantly higher in the FAI group (p = 0.01). There were no differences in ratios for other muscle groups. Angle of peak IR torque was the only feature correlated with symptoms.

Conclusions: Individuals with symptomatic FAI demonstrate isometric hip abductor muscle weakness and strength imbalance in the hip rotators. Strength measurement, including agonist/antagonist ratios, may be relevant for clinical management of FAI.
Keyword Femoroacetabular impingement
Hip joint
Hip strength
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID APP1002190
APP1058440
FT130100175
ID631717
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
Official 2016 Collection
School of Health and Rehabilitation Sciences Publications
 
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