A rigid-body method for finding centers of rotation and angular displacements of planar joint motion

Spiegelman, Jeffrey; Woo, Savio L‐Y.

doi:10.1016/0021-9290(87)90037-6

Cited by 62 publications

(25 citation statements)

References 12 publications

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“…The condition that needs to be fulfilled when following this method is that the studied joint is a planar mechanism operating over the plane scanned. A non-planar movement causes a virtual deformation of the rotating bone(s) and alters the reference coordinates used for estimating the joint centre of rotation, thus introducing errors in its estimated position (Panjabi and Goel 1982;Spiegelman and Woo 1987). Notwithstanding this limitation, the COR method is applicable under in vivo conditions and has often been applied for estimating the lengths of human muscle-tendon moment arms (e.g.…”

Section: Methods Of Moment Arm Length Estimationmentioning

confidence: 98%

Imaging-based estimates of moment arm length in intact human muscle-tendons

Maganaris

2004

European Journal of Applied Physiology

100

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The muscle-tendon moment arm length, i.e. the perpendicular distance from the muscle-tendon action line to the rotation centre of the joint that the muscle-tendon spans, is responsible for transforming muscle force and linear displacement to joint moment and rotation. In this paper, previous work on in vivo measurements of human muscle-tendon moment arms at rest and during isometric maximal voluntary contraction (MVC) is reviewed. The results obtained by actual measurements on 2-D magnetic resonance images indicate that the moment arm lengths of the Achilles and tibialis anterior tendons increase during MVC compared with rest by between 22% and 44%, due to (1) joint displacement, (2) muscle thickening and (3) stretching of collagenous structures mediating the action of tendon. However, moment arm length calculations based on the virtual work principle fail to show the above effect. Potentially severe mechanical limitations of the latter method as adapted under in vivo conditions raise questions about its validity during muscle contraction.

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Section: Methods Of Moment Arm Length Estimationmentioning

confidence: 98%

Imaging-based estimates of moment arm length in intact human muscle-tendons

Maganaris

2004

European Journal of Applied Physiology

100

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“…The axis of rotation was calculated for each joint using rigid body techniques (Spiegelman and Woo 1987) applied to vertebral position data digitized at five points over the entire range of vertebral movement observed in the three cats during voluntary head-tracking movements. Head tracking was characterized by aligning the computer model to the cats' vertebral alignment observed in the videofluoroscopic recordings during the tracking movement.…”

Section: Biomechanical Analysismentioning

confidence: 99%

Kinematics of the freely moving head and neck in the alert cat

1997

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In this study we examined connections between the moment-generating capacity of the neck muscles and their patterns of activation during voluntary head-tracking movements. Three cats lying prone were trained to produce sinusoidal (0.25 Hz) tracking movements of the head in the sagittal plane, and 22.5 degrees and 45 degrees away from the sagittal plane. Radio-opaque markers were placed in the cervical vertebrae, and intramuscular patch electrodes were implanted in five neck muscles, including biventer cervicis, complexus, splenius capitis, occipitoscapularis, and rectus capitis posterior major. Videofluoroscopic images of cervical vertebral motion and muscle electromyographic responses were simultaneously recorded. A three-dimensional biomechanical model was developed to estimate how muscle moment arms and force-generating capacities change during the head-tracking movement. Experimental results demonstrated that the head and vertebrae moved synchronously, but neither the muscle activation patterns nor vertebral movements were constant across trials. Analysis of the biomechanical model revealed that, in some cases, modification of muscle activation patterns was consistent with changes in muscle moment arms or force-generating potential. In other cases, however, changes in muscle activation patterns were observed without changes in muscle moment arms or force-generating potential. This suggests that the moment-generating potential of muscles is just one of the variables that influences which muscles the central nervous system will select to participate in a movement.

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“…In contrast to identifying the ICR, where three images are required, the location of the GCFC requires only one image, at the knee joint angle where d is required. This eliminates several potential errors introduced by inappropriate selection of rotation angles and reference landmarks on the rotationary segment in the estimation of the ICR (Panjabi et al 1982a, b;Spiegelman and Woo 1987). However, it should be considered that the knee joint does not rotate about the GCFC at extremely extended angles where the non-circular part of the femoral condyles come into contact with the tibia plateau (Churchill et al 1998;Eckhoff et al 2001;Freeman and Pinskerova 2005).…”

Section: Discussionmentioning

confidence: 97%

A comparison of different two-dimensional approaches for the determination of the patellar tendon moment arm length

et al. 2009

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The purpose of this study was to estimate and compare the moment arm length of the patellar tendon (d) during passive knee extension using three different reference landmarks; instant centre of rotation (ICR), tibiofemoral contact point (TFCP) and geometrical centre of the posterior femoral condyles (GCFC). Measurements were taken on the right leg on seven healthy males during passive knee rotation performed by the motor of a Cybex Norm isokinetic dynamometer. Moment arms lengths were obtained by analysing lateral X-ray images recorded using a GE FlexiView 8800 C-arm videofluoroscopy system. The d-knee joint angle relations with respect to GCFC and ICR were similar, with decreasing values from full knee extension (~5.8 cm for d (GCFC) and ~5.9 cm for d (ICR)) to 90 degrees of knee flexion (~4.8 cm for both d (GCFC) and d (ICR)). However, the d (TFCP)-knee joint angle relation had an ascending-descending shape, with the highest d (TFCP) value (~5 cm) at 60 degrees of knee flexion. There was no significant difference between the GCFC and ICR methods at any knee joint angle. In contrast, there were significant differences (P < 0.01) between d (ICR) and d (TFCP) at 0 degrees , 15 degrees , 30 degrees and 45 degrees of knee flexion and between d (GCFC) and d (TFCP) at 0 degrees , 15 degrees and 30 degrees of knee flexion (P < 0.01). This study shows that when using different knee joint rotation centre definitions, there are significant differences in the estimates of the patellar tendon moment arm length, especially in more extended knee joint positions. These differences can have serious implications for joint modelling and loading applications.

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A rigid-body method for finding centers of rotation and angular displacements of planar joint motion

Cited by 62 publications

References 12 publications

Imaging-based estimates of moment arm length in intact human muscle-tendons

Imaging-based estimates of moment arm length in intact human muscle-tendons

Kinematics of the freely moving head and neck in the alert cat

A comparison of different two-dimensional approaches for the determination of the patellar tendon moment arm length

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