that typically has a lower camera sampling frequency than other computer-based 2D motion analysis. As individuals with ACLR may exhibit more knee valgus 2 and there is limited data regarding the reliability/validity of using MAA to measure knee movement, it is necessary for validation of using a MAA
Kai-Yu Ho, Brenda Benson Deaver, Tyrel Nelson and Catherine Turner
Sergio Jiménez-Rubio, Archit Navandar, Jesús Rivilla-García, Víctor Paredes-Hernández and Miguel-Ángel Gómez-Ruano
can help interpret the actual physical exertion of the player and give meaningful information about the adequacy of workloads in training and competition. Different authors have validated RTP criteria following hamstring strain injuries, 21 but no one has used performance parameters from competition
Monna Arvinen-Barrow, Nathan Maresh and Jennifer Earl-Boehm
.1136/bjsports-2012-091203 23064083 21. Glazer DD . Development and preliminary validation and the Injury-Psychological Readiness to Return to Sport (I-PRRS) scale . J Athl Train . 2009 ; 44 : 185 – 189 . PubMed ID: 19295964 doi:10.4085/1062-6050-44.2.185 10.4085/1062-6050-44.2.185 19295964 22. Brewer BW
Daniel Gilfeather, Grant Norte, Christopher D. Ingersoll and Neal R. Glaviano
stimulus to the superior fibers resulted in a submaximal hip extension force production, there is a chance that the CAR measure is underestimated and could explain why we had lower reliability values compared with the GMed. In addition, validation of this measure in both larger populations, but also
David Werner, John Willson, Richard Willy and Joaquin Barrios
Frontal plane knee alignment can influence the development and management of various knee pathologies. Valid and reliable clinical methods for assessment are needed. The primary purposes of this study were to assess the validity and reliability of inclinometer-based frontal plane tibial orientation as a limb alignment measure, and secondarily to establish normal values in healthy individuals. Frontal tibial orientation was validated per moderately strong correlation to radiographic knee alignment. Intra- and interrater reliability were excellent. The normative mean was approximately 7°. In summary, inclinometer-based frontal tibial orientation is a valid and reliable clinical measure of frontal plane knee alignment.
Thomas D. Brown
Numerical approximation of the solutions to continuum mechanics boundary value problems, by means of finite element analysis, has proven to be of incalculable benefit to the field of musculoskeletal biomechanics. This article briefly outlines the conceptual basis of finite element analysis and discusses a number of the key technical considerations involved, specifically from the standpoint of effective modeling of musculoskeletal structures. The process of conceiving, developing, validating, parametrically exercising, and interpreting the results of musculoskeletal finite element models is described. Pertinent case study examples are presented from two series of finite element models, one involving total hip implant dislocation and the other involving femoral head osteonecrosis.
Shawn S. Kao, Richard W. Sellens and Joan M. Stevenson
A wind tunnel test was conducted to empirically determine the relationship between the Magnus force (M), spin rate (ω), and linear velocity (V) of a spiked volleyball. This relationship was applied in a two-dimensional mathematical model for the trajectory of the spiked volleyball. After being validated mathematically and empirically, the model was used to analyze three facets of play that a coach must address: the importance of topspin, possibility of overblock spiking, and optimum spiking points. It was found that topspin can increase the spiking effectiveness dramatically in many ways. It was also found that a shot spiked from about 2 m behind the net has the least possibility of being blocked.
Wei Liu, Jill Whitall and Thomas M. Kepple
Functional arm reaching involves multilinked joints: shoulder, elbow, and wrist. We propose that induced position analysis is a useful analytical tool for multijoint coordination of arm reaching. This method was used to compute the contributions of the net joint moment to the hand position when reaching forward. We describe the method and give examples of validating this model with motion capture data. The shoulder and elbow were prime movers of the arm: both acted together with an “overshoot” and “undershoot” pattern respectively to move the hand forward into the final position.
Rebecca J. Giorcelli, Richard E. Hughes, Richard S. Current and John R. Myers
This paper describes a procedure developed and validated to assess the accuracy of an infrared-based motion measurement system used to perform a kinematic analysis of the torso with respect to the pelvis during simulated lifting tasks. Two rigid reflective marker triads were designed and fabricated for attachment to the thorax over the 6th thoracic vertebra and the pelvis. System accuracy was assessed for planar rotation as well as rotations about multiple orthogonal axes. A test fixture was used to validate known triad orientations. The spatial coordinates of these triads were collected at 120 Hz using a ProReflex motion measurement system. Single value decomposition was used to estimate a rotation matrix describing the rigid body motion of the thorax triad relative to the sacral triad at each point in time. Euler angles corresponding to flexion, lateral bending, and twisting were computed from the rotation matrix. All measurement error residuals for flexion, lateral bending, and twisting were below 1.75°. The estimated mean measurement errors were less than 1° in all three planes. These results suggest that the motion measurement system is reliable and accurate to within approximately 1.5° for the angles examined.
This article presents the validation of a technique to assess the appropriateness of a 2 degree-of-freedom model for the human knee, and, in which case, the dominant axes of flexion/extension and internal/external longitudinal rotation are estimated. The technique relies on the use of an instrumented spatial linkage for the accurate detection of passive knee kinematics, and it is based on the assumption that points on the longitudinal rotation axis describe nearly circular and planar trajectories, whereas the flexion/extension axis is perpendicular to those trajectories through their centers of rotation. By manually enforcing a tibia rotation while bending the knee in flexion, a standard optimization algorithm is used to estimate the approximate axis of longitudinal rotation, and the axis of flexion is estimated consequently. The proposed technique is validated through simulated data and experimentally applied on a 2 degree-of-freedom mechanical joint. A procedure is proposed to verify the fixed axes assumption for the knee model. The suggested methodology could be possibly valuable in understanding knee kinematics, and in particular for the design and implant of customized hinged external fixators, which have shown to be effective in knee dislocation treatment and rehabilitation.