title: Eccentric and isometric shoulder rotator cuff strength testing using a hand-held dynamometer: reference values for overhead athletes.
abstract: OBJECTIVE
  In order to provide science-based guidelines for injury prevention or return to play, regular measurement of isometric and eccentric internal (IR) and external (ER) rotator strength is warranted in overhead athletes. However, up to date, no normative database exists regarding these values, when measured with a hand-held dynamometer. Therefore, the purpose of the study was to provide a normative database on isometric and eccentric rotator cuff (RC) strength values in a sample of overhead athletes, and to discuss gender, age and sports differences.
  
  
  METHODS
  A HHD was used to measure RC strength in 201 overhead athletes between 18 and 50 years old from three different sports disciplines: tennis, volleyball and handball. Isometric as well as eccentric strength was measured in different shoulder positions. Outcome variables of interest were isometric ER and IR strength, eccentric ER strength, and intermuscular strength ratios ER/IR.
  
  
  RESULTS
  Our results show significant side, gender and sports discipline differences in the isometric and eccentric RC strength. However, when normalized to body weight, gender differences often are absent. In general, strength differences are in favour of the dominant side, the male athletes and handball. Intermuscular ER/IR ratios showed gender, sports, and side differences.
  
  
  CONCLUSIONS
  This normative database is necessary to help the clinician in the evaluation of RC strength in healthy and injured overhead athletes. In view of the preventive screening and return-to-play decisions in overhead athletes, normalization to body weight and calculating intermuscular ratios are key points in this evaluation.
  
  
  METHODS
  Diagnostic study, Level III.
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium. ann.cools@ugent.be.
authors: Ann M J
authors: AM
authors: Cools
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium.
authors: Fran
authors: F
authors: Vanderstukken
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium.
authors: Frédéric
authors: F
authors: Vereecken
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium.
authors: Mattias
authors: M
authors: Duprez
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium.
authors: Karel
authors: K
authors: Heyman
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium.
authors: Nick
authors: N
authors: Goethals
authors: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital Ghent, De Pintelaan 185, 2B3, 9000, Ghent, Belgium.|Department of Environmental Medicine, Karolinska Institute, Musculoskeletal and Sports Injury Epidemiology Center (MUSIEC), Stockholm, Sweden.
authors: Fredrik
authors: F
authors: Johansson
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D016059:Range of Motion, Articular; D012016:Reference Values; D012399:Rotation; D017006:Rotator Cuff / Q000502:physiology*; D012782:Shoulder / Q000502:physiology; D012785:Shoulder Joint; D013715:Tennis; D054798:Volleyball; D055815:Young Adult
keywords: Hand-held dynamometer; Injury prevention; Normative database; Rotator cuff strength