Dual versus single force plate analysis of human drop jumping

Author(s):  
Stian Langgård Jørgensen ◽  
Jens Bojsen‐Møller ◽  
Thue Skalgard ◽  
Henrik B Olsen ◽  
Per Aagaard
Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 63
Author(s):  
Jonathan Shepherd ◽  
Erik Henrikson ◽  
Scott Lynn ◽  
Paul Wood

Golf is a sport which requires players to use ground interaction to generate clubhead speed in order to propel the ball towards the target. Force platforms are a technology which can be used to measure these ground reaction forces. Golfers generate force through a combination of jumping, sliding or twisting actions during the swing. Understanding how golfers generate these forces and if there are any groups which golfers could be clustered into could be used to enhance golf instruction as well as clubhead design or fitting practices for golf equipment. A total of 105 right-handed experienced golfers (handicap mean = 8.32 ± 8.31) consented to participate in the study of different swing speeds (31 below 95 mph, 41 over 105 mph and 33 between 95 and 105 mph). A calibrated single force plate was used for the test which sampled at 1000 Hz and recorded force and moment data in three axes. After a self-guided warm up, the players were instructed to hit five 7-iron shots and five drives to the best of their ability in an indoor hitting bay which used a launch monitor to record the club delivery and ball flight information. It was found that handicap or swing speed did not dictate the primary force production mechanism (sliding, jumping or twisting/spinning). This knowledge could aid engineers to design equipment better suited to the individual and help coaches build individualized programs to create power and clubhead speed in all players.


2014 ◽  
Vol 27 (03) ◽  
pp. 243-248 ◽  
Author(s):  
T. Sparrow ◽  
J. Meswania ◽  
G. Blunn ◽  
N. Fitzpatrick

SummaryIntroduction: Partial resurfacing of the humeral head has been reported in humans to treat humeral osteochondritis dissecans. The aim is to describe a custom-made humeral resurfacing prosthesis for treatment of severe humeral head osteochondritis dissecans in a dog.Case report: A seven-month-old female entire St. Bernard dog was presented with a 10 week history of severe left thoracic limb lameness. Radiography, arthroscopy and magnetic resonance imaging confirmed an extensive osteochondritis dissecans lesion affecting the caudal, medial and central regions of the humeral head. A prosthesis designed from computed tomography (CT) images was manufactured in polished stainless steel alloy with a hydroxyapatite coated base and central finned humeral stem for cementless insertion. A standard caudal approach to the shoulder was used to place the prosthesis following reaming of the caudal humeral head.Results: Radiography and CT imaging revealed appropriate topographical placement on the humerus. Force plate analysis demonstrated initial reduction in ground reaction force at six weeks, followed by gradual improvement at three months. There was no radiographic evidence of implant loosening and the range of shoulder joint motion was comparable to the contralateral joint at three months; these findings were maintained to final follow-up at 24 months.Clinical significance: Placement of a humeral head resurfacing prosthesis was an effective technique for the management of severe osteochondritis dissecans-related shoulder lameness. To the authors’ knowledge, this is the first report of the clinical use of shoulder hemiarthroplasty in a dog.


1996 ◽  
Vol 24 (6) ◽  
pp. 353 ◽  
Author(s):  
DR Petersen ◽  
RE Link ◽  
FL Buczek ◽  
SA Banks

2012 ◽  
Vol 518-523 ◽  
pp. 639-646
Author(s):  
Wang Yi ◽  
Hang Xu ◽  
Andrew Merryweather

The article studies the way of combining double foot data into one gait cycle from data collected from only one force plate, and the reliability with comparing the Root Mean Square Error (RMSE) between combined and original trails is validated. The joint moment values, knee muscles value were also computed by OpenSim based on the dynamic model. Correlation coefficients and normalized RMSE were used as the compared factors between two trails. Correlation coefficients are all above 0.9 for joint moments, and all above 0.95 for knee muscles except for biceps femoris - long head. The technology would get higher reliability and improving the accuracy of simulation result by increasing the numbers of collection trails and selecting pairs trails which got higher correlation coefficients.


1992 ◽  
Vol 114 (4) ◽  
pp. 435-441 ◽  
Author(s):  
J. R. Iversen ◽  
T. A. McMahon

Seven male subjects ran at 3.0 m/s on a motorized treadmill including a force platform under the tread. The subjects ran at each of five treadmill inclinations: + 0.17, +0.077, 0, -0.077, and -0.17 radians. The position of the subjects’ legs were read from cine´ films (100 frames/s). Results of the film and force plate analysis generally corroborated the “hanging triangle” hypothesis, which postulates that the angle between the leg and the vertical upon foot strike does not change as the treadmill is tipped up or down. A mathematical model of running, in which the leg is represented as a nonlinear spring, made satisfactory predictions of the way many parameters of running change with the treadmill angle, including the length of the leg at touchdown and liftoff and the peak leg force in the middle of a step. The peak leg force reaches a maximum at a treadmill angle near −0.12 radians, close to the downhill angle where other authors have found a minimum in the rate of oxygen consumption.


1995 ◽  
Vol 24 (1) ◽  
pp. 15-24 ◽  
Author(s):  
PETER MUIR ◽  
MARK D. MARKEL ◽  
JOHN J. BOGDANSKE ◽  
KENNETH A. JOHNSON

2014 ◽  
Vol 39 (1) ◽  
pp. 631-633 ◽  
Author(s):  
Bastien Moineau ◽  
Matthieu P. Boisgontier ◽  
Guillaume Barbieri ◽  
Vincent Nougier

2010 ◽  
Vol 2 (2) ◽  
pp. 3481
Author(s):  
Christian Baumgart ◽  
Volker Lange-Berlin ◽  
Rüdiger Hofmann ◽  
Jürgen Freiwald

1995 ◽  
Vol 08 (04) ◽  
pp. 177-183 ◽  
Author(s):  
C. W. Miller ◽  
C. L. Taves ◽  
G. R. Bouck

SummaryA randomized prospective clinical study was performed to compare the effect of surgery for fragmented coronoid process (FCP) and osteochondritis dissecans (OCD) of the canine elbow, with medical treatment using pentosan polysulphate (PPS). Nineteen dogs with FCP and/or OCD of the elbow were randomly assigned to either the surgical or medical group. Lameness examination, radiographic evaluation and force plate analysis were performed at the time of admission, and were repeated at two, four, six and nine months after treatment. In dogs with asymmetrical lameness, in both the medical and surgical groups, the peak vertical forces and mean vertical forces for the more affected limbs were significantly lower than the control means at time zero. In both the medical and surgical group, the peak and mean vertical forces improved during the course of the study. Weightbearing in medically treated dogs approached that in controls at a faster rate than in those treated surgically. After nine months of follow-up, differences could not be detected between the dogs treated surgically, and those treated with PPS.Surgical and medical treatment for fragmented coronoid process and osteochondritis dissecans of the canine elbow were compared. Medical treatment resulted in a more rapid return to normal weight-bearing than did surgical treatment. After nine months of follow-up, differences were not detected between the medically and surgically treated dogs.


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