title: Scapular muscle performance in individuals with lateral epicondylalgia.
abstract: METHODS
  Descriptive, laboratory-based, cross-sectional study.
  
  
  OBJECTIVE
  To describe scapular musculature strength, endurance, and change in thickness in individuals with unilateral lateral epicondylalgia (LE) compared to the uninvolved limb and the corresponding limb of a matched comparison group.
  
  
  BACKGROUND
  Reported poor long-term outcomes for the nonsurgical management of individuals with LE suggest a less-than-optimal rehabilitation process. Knowledge of scapular muscle function in a working population of individuals with LE may help to further refine conservative management of this condition.
  
  
  METHODS
  Twenty-eight patients with symptomatic LE and 28 controls matched by age and sex were recruited to participate in the study. Strength of the middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) was measured with a handheld dynamometer. A scapular isometric muscle endurance task was performed in prone. Changes in muscle thickness of the SA and LT were measured with ultrasound imaging. Analysis-of-variance models were used to determine within- and between-group differences.
  
  
  RESULTS
  The involved side of the group with LE had significantly lower values for MT strength (P = .031), SA strength (P<.001), LT strength (P = .006), endurance (P = .003), and change in SA thickness (P = .028) when compared to the corresponding limb of the control group. The involved side of the group with LE had significantly lower strength of the LT (P = .023) and SA (P = .016) when compared to the uninvolved limb; however, these differences were small and of potentially limited clinical significance.
  
  
  CONCLUSIONS
  When compared to a matched comparison group, there were impairments of scapular musculature strength and endurance in patients with LE, suggesting that the scapular musculature should be assessed and potentially treated in this population. Cause and effect cannot be established, as the weakness of the scapular musculature could be a result of LE.
authors.affiliation: Department of Physical Therapy, University of South Alabama, Mobile, AL.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Day
authors.forename: Heather
authors.initials: H
authors.lastname: Bush
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Nitz
authors.forename: Tim L
authors.initials: TL
authors.lastname: Uhl
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010807:Physical Endurance / Q000502:physiology; D012540:Scapula / Q000503:physiopathology*; D013716:Tennis Elbow / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography
keywords: serratus anterior; strength; trapezius; ultrasound imaging