PMID- 11138576
OWN - NLM
STAT- MEDLINE
DCOM- 20010503
LR  - 20191210
IS  - 1439-6319 (Print)
IS  - 1439-6319 (Linking)
VI  - 83
IP  - 4 -5
DP  - 2000 Nov
TI  - In vivo measurement-based estimations of the human Achilles tendon moment arm.
PG  - 363-9
AB  - The aim of the present study was to estimate and compare in vivo 
      measurement-based Achilles tendon moment arm lengths at rest and during isometric 
      plantarflexion maximum voluntary contraction (MVC) using the centre-of-rotation 
      (COR) and the tendon-excursion (TE) methods. Both methods were based on 
      morphometric analysis of sagittal-plane magnetic resonance images of the foot. 
      Using the COR method, moment arms were obtained at ankle angles from 15 degrees 
      of dorsiflexion to 30 degrees of plantarflexion in steps of 15 degrees, 
      digitizing the perpendicular distance from a moving centre of rotation in the 
      tibio-talar joint to the Achilles tendon action line. The TE method was based on 
      measurement of calcaneal displacement along the tibial axis during 15 degrees 
      rotations of the ankle joint, from 30 degrees of dorsiflexion to 45 degrees of 
      plantarflexion. The two methods gave similar estimations at rest varying from 4.3 
      to 5.6 cm. Using the COR method, the Achilles tendon moment arm during MVC was 
      larger by 1-1.5 cm (22-27%, P < 0.01) than the respective resting value. In 
      contrast, no difference (P > 0.05) was found between the resting and MVC moment 
      arm estimations of the TE method. The disagreement in moment arms during MVC may 
      be attributed to differences in the assumptions made between the two methods. The 
      TE method has more limitations than the COR method and its estimations during MVC 
      should be treated with caution. Resting Achilles tendon moment arm estimations of 
      the COR method should be multiplied by 1.22-1.27 when maximal isometric 
      plantarflexion joint moments, musculotendon forces and stresses are predicted 
      using modelling.
FAU - Maganaris, C N
AU  - Maganaris CN
AD  - University of Tokyo, Komaba, Department of Life Sciences, Meguro, Japan. 
      costis.maganaris@strath.ac.uk
FAU - Baltzopoulos, V
AU  - Baltzopoulos V
FAU - Sargeant, A J
AU  - Sargeant AJ
LA  - eng
PT  - Comparative Study
PT  - Evaluation Study
PT  - Journal Article
PL  - Germany
TA  - Eur J Appl Physiol
JT  - European journal of applied physiology
JID - 100954790
SB  - IM
MH  - Achilles Tendon/*anatomy & histology
MH  - Adult
MH  - Biomechanical Phenomena
MH  - Humans
MH  - Isometric Contraction
MH  - *Magnetic Resonance Imaging
MH  - Male
MH  - Reproducibility of Results
MH  - Rotation
EDAT- 2001/01/04 11:00
MHDA- 2001/05/05 10:01
CRDT- 2001/01/04 11:00
PHST- 2001/01/04 11:00 [pubmed]
PHST- 2001/05/05 10:01 [medline]
PHST- 2001/01/04 11:00 [entrez]
AID - 10.1007/s004210000247 [doi]
PST - ppublish
SO  - Eur J Appl Physiol. 2000 Nov;83(4 -5):363-9. doi: 10.1007/s004210000247.