title: Prevalence of Scapular Dyskinesis in Overhead and Nonoverhead Athletes: A Systematic Review.
abstract: BACKGROUND
  Scapular dyskinesis, or abnormal dynamic scapular control, is a condition that is commonly associated with shoulder pathology but is also present in asymptomatic individuals. Literature varies on whether it represents a cause or symptom of shoulder pathology, but it is believed to be a risk factor for further injury. Clinical identification focuses on visual observation and examination maneuvers. Treatment of altered scapular motion has been shown to improve shoulder symptoms. It is thought to be more common in overhead athletes due to their reliance on unilateral upper extremity function but the incidence within nonoverhead athletes is unknown.
  
  
  OBJECTIVE
  Overhead athletes will have a greater prevalence of scapular dyskinesis when compared with nonoverhead athletes.
  
  
  METHODS
  Systematic review; Level of evidence, 3.
  
  
  METHODS
  After PROSPERO registration, a systematic review was performed using PRISMA guidelines through the PubMed database looking for studies published before October 2014. All studies containing the search terms scapular, scapulothoracic, dyskinesis, dyskinesia, shoulder athlete, or overhead athlete were included. Studies that did not include prevalence data for scapular dyskinesis were excluded. Study methodological quality was evaluated using the modified Coleman methodology score. Descriptive statistics and 2-proportion 2-tailed z-tests were used to compare the reported prevalence of scapular dyskinesis between overhead and nonoverhead athletes.
  
  
  RESULTS
  Twelve studies were analyzed including 1401 athletes (1257 overhead and 144 nonoverhead; mean age, 24.4 ± 7.1 years; 78% men). All the studies were evidence level 2 (33%) or level 3 (67%). The reported prevalence of scapular dyskinesis was significantly (P < .0001) higher in overhead athletes (61%) compared with nonoverhead athletes (33%).
  
  
  CONCLUSIONS
  Scapular dyskinesis was found to have a greater reported prevalence (61%) in overhead athletes compared with nonoverhead athletes (33%).
  
  
  CONCLUSIONS
  Prevalence data for scapular dyskinesis are scarce within the literature. Information on the reported prevalence, laterality, and association with the dominant extremity will allow for better allocation of diagnostic and therapeutic interventions. Recognition and treatment will help athletes to optimize functional performance and decrease the risk of further shoulder injury.
authors.affiliation: Houston Methodist Hospital, Department of Orthopedics & Sports Medicine, Houston, Texas, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Burn
authors.affiliation: Houston Methodist Hospital, Department of Orthopedics & Sports Medicine, Houston, Texas, USA.
authors.forename: Patrick C
authors.initials: PC
authors.lastname: McCulloch
authors.affiliation: Houston Methodist Hospital, Department of Orthopedics & Sports Medicine, Houston, Texas, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Lintner
authors.affiliation: Houston Methodist Hospital, Department of Orthopedics & Sports Medicine, Houston, Texas, USA.
authors.forename: Shari R
authors.initials: SR
authors.lastname: Liberman
authors.affiliation: Houston Methodist Hospital, Department of Orthopedics & Sports Medicine, Houston, Texas, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Harris
keywords: athlete; overhead; prevalence; scapula; scapular dyskinesia; scapular dyskinesis; scapulohumeral rhythm; shoulder