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Abderrehmane Rahmani, Georges Dalleau, Fabrice Viale, Christophe A. Hautier and Jean-René Lacour

This study determined the validity and reliability of the kinematic device developed by Bosco et al. (1995) by comparing its peak force, peak velocity, and peak power measurements to data obtained simultaneously with a force platform placed under the subject’s feet. Fifteen international downhill skiers performed maximal half-squats on a guided barbell with masses of 60–180 kg. The coefficient of correlation (r) between the two peak forces (r = 0.85–0.95, p < .001), the two peak velocities (r = 0.74–0.91, p < .001), and the two peak powers (r = 0.85–0.95, p < .001) indicated that the kinematic device measurements were valid. The trial-to-trial reliability of half-squat exercises measured by the kinematic device gave an intraclass coefficient of correlation (CR) of: 0.70-0.90 for peak force, 0.62-0.90 for peak velocity, and 0.57-0.91 for peak power. There were no statistical differences between the two trials. The standard error of the means (SEM%) was less than 5% for peak force, less than 4% for peak velocity, and less than 7% for power. The high CR and low SEM% indicate that the kinematic device is reliable. The movement recorded by the kinematic device accurately described the action measured by the force platform.

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Gabriel Andrade Paz, Marianna de Freitas Maia, Haroldo Gualter Santana, Humberto Miranda, Vicente Lima and John D. Willson

reason for the disparity in the number of serious knee injuries, such as ACL rupture, between male and female athletes. 11 , 15 Greater knee valgus angles and interlimb hip and knee joint sagittal and frontal plane kinematic asymmetries are reported to be more common in females compared with males. 5

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Bryan R. Picco, Meghan E. Vidt and Clark R. Dickerson

data for comparison, although a benchmark is unavailable 5 for sex-specific scapular kinematics. Characteristics of male and female anatomy, including anthropometry and segment masses, 6 quantity of skeletal muscle mass, 7 and muscle activation patterns, 8 may contribute to different scapular

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Helga T. Tucci, Lilian R. Felicio, Kevin J. McQuade, Debora Bevilaqua-Grossi, Paula Maria Ferreira Camarini and Anamaria S. Oliveira

Context:

The closed kinetic chain upper-extremity stability (CKCUES) test is a functional test for the upper extremity performed in the push-up position, where individuals support their body weight on 1 hand placed on the ground and swing the opposite hand until touching the hand on the ground, then switch hands and repeat the process as fast as possible for 15 s.

Objective:

To study scapular kinematic and kinetic measures during the CKCUES test for 3 different distances between hands.

Design:

Experimental.

Setting:

Laboratory.

Participants:

30 healthy individuals (15 male, 15 female).

Main Outcome Measures:

Participants performed 3 repetitions of the test at 3 distance conditions: original (36 in), interacromial, and 150% interacromial distance between hands. Participants completed a questionnaire on pain intensity and perceived exertion before and after the procedures. Scapular internal/external rotation, upward/downward rotation, and posterior/anterior tilting kinematics and kinetic data on maximum force and time to maximum force were measured bilaterally in all participants. Percentage of body weight on upper extremities was calculated. Data analyses were based on the total numbers of hand touches performed for each distance condition, and scapular kinematics and kinetic values were averaged over the 3 trials. Scapular kinematics, maximum force, and time to maximum force were compared for the 3 distance conditions within each gender. Significance level was set at α = .05.

Results:

Scapular internal rotation, posterior tilting, and upward rotation were significantly greater in the dominant side for both genders. Scapular upward rotation was significantly greater in original distance than interacromial distance in swing phase. Time to maximum force in women was significantly greater in the dominant side.

Conclusion:

CKCUES test kinematic and kinetic measures were not different among 3 conditions based on distance between hands. However, the test might not be suitable for initial or mild-level rehabilitation due to its challenging requirements.

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Yungchien Chu, Glenn S. Fleisig, Kathy J. Simpson and James R. Andrews

The purpose of the current study was to identify the biomechanical features of elite female baseball pitching. Kinematics and kinetics of eleven elite female baseball pitchers were reported and compared with eleven elite male pitchers. Results suggested that females share many similarities with males in pitching kinematics, with a few significant differences. Specifically, at the instant of stride foot contact, a female pitcher had a shorter and more open stride and less separation between pelvis orientation and upper torso orientation. From foot contact to ball release, a female pitcher produced lower peak angular velocity for throwing elbow extension and stride knee extension. Ball velocity was lower for the female. Foot contact to ball release took more time for a female pitcher. Maximal proximal forces at the shoulder and elbow joints were less for a female pitcher.

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Joseph M. Hart, Jamie L. Leonard and Christopher D. Ingersoll

Context:

Despite recent findings regarding lower extremity function after cryotherapy, little is known of the neuromuscular, kinetic, and kinematic changes that might occur during functional tasks.

Objective:

To evaluate changes in ground-reaction forces, muscle activity, and knee-joint flexion during single-leg landings after 20-minute knee-joint cryotherapy.

Design:

1 × 4 repeated-measures, time-series design.

Setting:

Research laboratory.

Patients or Other Participants:

20 healthy male and female subjects.

Intervention:

Subjects performed 5 single-leg landings before, immediately after, and 15 and 30 minutes after knee-joint cryo-therapy.

Main Outcome Measures:

Ground-reaction force, knee-joint flexion, and muscle activity of the gastrocnemius, hamstrings, quadriceps, and gluteus medius.

Results:

Cryotherapy did not significantly (P > .05) change maximum knee-joint flexion, vertical ground-reaction force, or average muscle activity during a single-leg landing.

Conclusion:

Knee-joint cryotherapy might not place the lower extremity at risk for injury during landing.

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Christian A. Clermont, Sean T. Osis, Angkoon Phinyomark and Reed Ferber

Research has shown that certain homogeneous subgroups demonstrate distinct kinematic patterns in running. For example, running patterns have been reported in subgroups related to sex, 1 – 3 running mileage, 4 foot strike patterns, 5 – 9 and running economy. 10 – 12 Running economy is often

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Christopher Napier, Christopher L. MacLean, Jessica Maurer, Jack E. Taunton and Michael A. Hunt

However, in a clinical setting, it is not always feasible to provide real-time feedback of ground reaction force variables due to constraints on equipment, costs, and analytic methods. Fortunately, many kinematic variables can be measured and modified in a clinical setting using 3-dimensional motion

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David S. Haydon, Ross A. Pinder, Paul N. Grimshaw and William S.P. Robertson

Wheelchair-propulsion kinematics have been investigated across a range of activities including wheelchair basketball, 1 wheelchair racing, 2 and daily living. 3 Variables such as contact and release angles, as well as stroke and recovery times, have been used to assess variations across athlete

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Melissa M.B. Morrow, Bethany Lowndes, Emma Fortune, Kenton R. Kaufman and M. Susan Hallbeck

Upper body kinematic measures are widely used in ergonomics, 1 , 2 orthopedics, 3 , 4 and rehabilitation 5 – 7 to describe normal and pathological motion of the trunk, head, and arms. Traditional methods of motion capture utilize marker-based and electromagnetic laboratory-based systems to