title: Effects of habitual loading on patellar tendon mechanical and morphological properties in basketball and volleyball players.
abstract: OBJECTIVE
  Tendon mechanical properties are linked to sports performance and tendon-related injuries, such as tendinopathy. Whether habitual loading, such as participation in regular jumping activities, would induce adaptation on tendon mechanical properties remains unclear.
  
  
  METHODS
  Forty healthy subjects (10 sedentary, 15 volleyball players, and 15 basketball players) aged between 18 and 35 years were recruited. Supersonic shearwave imaging was used to measure the shear elastic modulus and thickness and cross-sectional area (CSA) of the proximal patellar tendons of both knees at 30° of flexion.
  
  
  RESULTS
  Significant group differences in tendon shear elastic modulus were found among the three groups. In the dominant leg, reduction in tendon shear elastic modulus by 18.9 % (p = 0.018) and 48.7 % (p = 0.000) were observed in the basketball and volleyball players, respectively, when compared with sedentary subjects. In the non-dominant leg, reduction in tendon shear elastic modulus were 27.3 % (p = 0.034) and 47.1 % (p = 0.02) in the basketball and volleyball players, respectively. The athlete groups were found to have larger CSA but with similar tendon thickness than sedentary group. The CSA were larger by 24-29 % and by 22-24 % in the basketball players and volleyball players, for the dominant and non-dominant legs, respectively (all p < 0.05). Age and body mass are related to tendon stiffness and CSA, particularly in the sedentary subjects.
  
  
  CONCLUSIONS
  The proximal patellar tendon can undergo substantial adaptation on tendon mechanical and morphological properties when exposed in jumping sports. Intrinsic factors such as age and body mass could influence tendon properties.
authors.affiliation: Guangdong-Hongkong Joint Sports Rehabilitation and Research Center, Guangdong Provincial Work Injury Rehabilitation Hospital, Guangzhou, China.|Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Zhang
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: G Y F
authors.initials: GY
authors.lastname: Ng
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. amy.fu@polyu.edu.hk.
authors.forename: S N
authors.initials: SN
authors.lastname: Fu
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D056352:Athletes; D001490:Basketball / Q000502:physiology*; D015992:Body Mass Index; D055119:Elastic Modulus / Q000502:physiology; D006801:Humans; D008297:Male; D017847:Patellar Ligament / Q000033:anatomy & histology / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D054798:Volleyball / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
keywords: Basketball; Tendon adaptation; Tendon mechanical properties; Tendon morphological properties; Volleyball