Search Results

You are looking at 11 - 20 of 451 items for :

  • "motion analysis" x
Clear All
Restricted access

Gustavo Ramos Dalla Bernardina, Tony Monnet, Heber Teixeira Pinto, Ricardo Machado Leite de Barros, Pietro Cerveri and Amanda Piaia Silvatti

Optoelectronic motion capture systems (MOCAP), such as Vicon (Oxford Metrics Ltd, Oxford, United Kingdom), Elite (BTS, Milan, Italy), Qualisys (Göteborg, Sweden), Motion Analysis (Motion Analysis Corp, Santa Rosa, CA), and OptiTrack (NaturalPoint, Inc, Corvallis, OR), are considered to be the

Restricted access

Dominique C. Leibbrandt and Quinette A. Louw

series was to investigate an individualized FMR approach on 8 subjects with AKP using subjects’ unaffected legs as a control to allow for individual variation in etiology and symptoms. Methods Setting The motion analysis was done at the 3D motion analysis at the Tygerberg CAF Motion Analysis Laboratory

Restricted access

Susana Meireles, Neil D. Reeves, Richard K. Jones, Colin R. Smith, Darryl G. Thelen and Ilse Jonkers

imaging; OA, osteoarthritis. Motion analysis was performed while barefoot ascending and descending a staircase consisting of seven 17.2-cm height steps (Figure  1 ). A 10-camera 3-dimensional motion capture system (Vicon Motion Systems Inc, Los Angeles, CA) synchronized with 4 force platforms (embedded in

Restricted access

Colin Higgs

Wheelchair racquetball players in the A and B divisions of the 1989 Canadian Racquetball Championships were videotaped and their performances were analyzed. The results indicated that the athletes had an exercise-to-pause ratio of 1:1.5 at the A level and 1:2.3 at the B level. Rallies were slightly longer at the higher level, with substantially longer pause periods at the B level. There was a higher percentage of longer rallies at the A level, although both divisions of play had comparable percentages of forehand and backhand shots. A-level players demonstrated greater distances covered per rally, greater wheelchair speed, and a higher degree of wheelchair maneuverability measured by the number and magnitude of directional changes. In particular, A-level players showed a greater tendency to use small directional corrections, particularly turns to the right of less than 45 °. It is suggested that this action allowed a less restricted backswing for powerful forehand shots.

Restricted access

Howard J. Hillstrom, Rohit Garg, Andrew Kraszewski, Mark Lenhoff, Timothy Carter, Sherry I. Backus, Aviva Wolff, Grigory Syrkin, Richard Cheng and Scott W. Wolfe

The purpose of this study was to develop a three-dimensional (3D) motion analysis based anatomical wrist joint coordinate system for measurement of in-vivo wrist kinematics. The convergent validity and reliability of the 3D motion analysis implementation was quantified and compared with manual and electrogoniometry techniques on 10 cadaveric specimens. Fluoroscopic measurements were used as the reference. The 3D motion analysis measurements (mean absolute difference [MAD] = 3.6°) were significantly less different (P < .005) than manual goniometry (MAD = 5.7°) but not (P = .066, power = 0.45) electrogoniometry (MAD = 5.0°) compared with fluoroscopy. The intraclass correlation coefficient (ICC[2,1]) was highest for 3D motion analysis compared with manual and electrogoniometry, suggesting better reliability for this technique. To demonstrate the utility of this new wrist joint coordinate system, normative data from 10 healthy subjects was obtained while throwing a dart.

Restricted access

Teresa Alentejano, Dru Marshall and Gordon Bell

Purpose:

To determine the total amount and relative time periods of face immersion (FI) in a synchronized swimming solo routine and the relationship between FI, distance covered, and the technical-merit score of the 11 top Canadian soloists at a synchronized swimming national championship (mean age 20 ± 1.8 y, height 173.3 ± 4.1 cm, and body mass 58.3 ± 4 kg).

Methods:

Videotape and timing of solo performances combined with manual tracking of pool patterns.

Results:

Analysis of performance revealed that an average of 18 FI periods, mean of 6.8 s, were performed for an average total time of 133.7 ± 27.1 s (range 102.2 to 199.8 s). The average longest FI time period was 25.45 ± 6.2 s (range 18.18 to 38.72 s), and most (10/11) of these were in the first third of the solo. The mean total horizontal distance covered was 57.61 ± 6.84 m (range 48.61 to 68.2 m), and the total horizontal distance covered relative to time was 0.276 ± 0.034 m/s (range 0.235 to 0.340 m/s). No significant relationships were found between any of the FI periods and the distance covered or between the technical-merit score and FI periods. Each solo contained 6 to 8 underwater sequences, none of which were longer than 40 seconds, the cutoff deemed dangerous by FINA (Fédération Internationale de Natation).

Conclusion:

This study shows that the times underwater for solos in Canada are within safety limits recommended by FINA and that judging in Canada is not related to underwater periods of swimming.

Restricted access

Pirjo Kejonen, Kari Kauranen, Ahti Niinimaa and Heikki Vanharanta

Context:

Balance evaluation and training are typically included in rehabilitation after sport injuries.

Objective:

To evaluate and compare the maximal velocities and accelerations of balancing movements during 2-leg stance with eyes open and closed. The effect of age on the measured values was also evaluated.

Design:

Cross-sectional study.

Participants:

100 healthy, randomly selected subjects (50 men, 50 women; age 31–80 years).

Setting:

Body-movement values were measured with the Mac Reflex motion-analysis system.

Intervention:

Subjects stood barefoot.

Main Outcome Measures:

ANOVAs were used to explain the body movements. The location of measurement, presence or absence of vision, and subjects’ age and gender were used as explanatory variables.

Results:

With eyes closed, all measured body parts had significantly higher maximal velocity and acceleration values than with eyes open. Age seemed to affect the acceleration values.

Conclusion:

Visual information was found to significantly influence movement values. Exercises should be done under various conditions to improve standing balance abilities.

Restricted access

Helen Crewe, Amity Campbell, Bruce Elliott and Jacqueline Alderson

This study aimed to assess variability in lumbo-pelvic forces and moments during a dynamic high-impact activity (cricket fast bowling) when calculated using different body segment parameters (BSPs). The first three BSPs were estimated using methods where the trunk was divided into segments according to nonspinal anatomical landmarks. The final approach defined segment boundaries according to vertebral level. Three-dimensional motion analysis data from nine male cricketers’ bowling trials were processed using the four BSPs. A repeated-measures analysis of variance revealed no significant effect on peak lumbo-pelvic forces. However, the segmentation approach based on vertebral level resulted in significantly larger peak flexion and lateral flexion moments than the other BSP data sets. This has implications for comparisons between studies using different BSPs. Further, given that a method defined with reference to vertebral level more closely corresponds with relevant anatomical structures, this approach may more accurately reflect lumbar moments.

Restricted access

Stacy E. Stamm and Loren Z.F. Chiu

When the rear- and forefoot are constrained, calcaneal plantar flexion may occur, deforming the longitudinal arch. Previous research has reported calcaneal motion relative to the tibia or forefoot; these joint rotations may not accurately describe rotation of the calcaneus alone. This investigation: (1) characterized the calcaneus and leg segment and ankle joint rotations during stance in gait, and (2) described the range of calcaneal plantar flexion in different structural arch types. Men (n = 14) and women (n = 16) performed gait in a motion analysis laboratory. From heel strike to heel off, the leg rotated forward while the calcaneus plantar flexed. Before foot flat, calcaneal plantar flexion was greater than forward leg rotation, resulting in ankle plantar flexion. After foot flat, forward leg rotation was greater than calcaneal plantar flexion, resulting in ankle dorsiflexion. Structural arch type was classified using the longitudinal arch angle. The range of calcaneal plantar flexion from foot flat to heel off was small in low (−2° to −8°), moderate in high (−3° to −12°), and large in normal (−2° to −20°) structural arches. Calcaneal plantar flexion in gait during midstance may reflect functional arch characteristics, which vary depending on structural arch type.

Restricted access

Jennifer L. Bruno, Zhizhong Li, Matthieu Trudeau, Sachin M. Raina and Jack T. Dennerlein

The goal of this study was to evaluate the performance of a single video camera system for measuring shoulder rotation during computer work, and to quantify the work and postural space within which the system performs optimally. Shoulder rotation angles calculated using the video system were compared with angles calculated using an active infrared LED three-dimensional motion analysis system while 10 adult volunteers simulated postures for two different trials: typical of normal computer work (freestyle) and with forced shoulder abduction (constrained). Average and absolute errors were calculated to determine the accuracy and precision of the system, respectively, for each trial, for each position, and for both the right and left hands. For the right hand, mean values for the average and absolute errors were –1 and 0 degrees, respectively. Only the absolute error increased significantly to 12 degrees for the constrained posture compared with freestyle. During normal computer work, the video system provided shoulder rotation angle values similar to those of a three-dimensional system, thus making it a viable and simple instrument to use in field studies.