title: Gastrocnemius muscle-tendon behaviour during walking in young and older adults.
abstract: OBJECTIVE
  Age-related differences in muscle architectural and tendon mechanical properties have been observed in vivo under static conditions and during single joint contractions. The aim of this study was to determine if there are age-related differences in gastrocnemius fascicle-tendon interactions during a fundamental locomotor task - walking.
  
  
  METHODS
  Eight young adults (YA; 27 +/- 4 years) and eight older adults (OA; 77 +/- 4 years) walked on a treadmill at 1.11 m s(-1) whilst length changes in the gastrocnemius lateralis muscle tendon complex (MTC), fascicles and tendinous tissue (TT) were determined from joint angles, ultrasonography and a geometric MTC model (combining MTC and fascicle measurements) respectively.
  
  
  RESULTS
  There was no age-related difference in lengthening of the MTC during stance. However, the fascicle and TT contribution to MTC lengthening was altered; TT lengthening was larger in OA than in YA (P = 0.05) and fascicle lengthening was less in OA than YA (P < 0.05). There were no differences between groups in MTC, fascicle or TT shortening amplitude during push-off.
  
  
  CONCLUSIONS
  The observations are consistent with previous reports of increased compliance of TT in older adults.
authors.affiliation: Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University, Cheshire, UK. o.mian@mmu.ac.uk
authors.forename: O S
authors.initials: OS
authors.lastname: Mian
authors.forename: J M
authors.initials: JM
authors.lastname: Thom
authors.forename: L P
authors.initials: LP
authors.lastname: Ardigò
authors.forename: A E
authors.initials: AE
authors.lastname: Minetti
authors.forename: M V
authors.initials: MV
authors.lastname: Narici
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001696:Biomechanical Phenomena; D004576:Electromyography / Q000379:methods; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D013710:Tendons / Q000502:physiology*; D016138:Walking / Q000502:physiology*