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Effect of foot orthotics on the kinematics of the knee joint
Abstracts-International
Society
of Biomechanics
XII
Congress
1007
1989
A 7btal Arm Strength Isokiwtic Profile of Highly Skilled Tennis Players and Its Relation to a Functional Perform Lincoln Institute for Athletic Medicine. Arizona State University ante Kwmemnt, Todd S. Ellenbecker, P.T., Departmnt of Exercise Science, Tenpe, Arizona U.S.A. Isokinetic testing of 22 male highly skilled tennis players was done using a Cybex II dyrmmeter and Li Tests wre conducted bilaterally for shoulder internal/ Discipline Rlll carputerized data reduction system. external rotation, flexion/extension, forearm pronation/supination and wrist flexion/extension at speeds of ‘%, 210 Initial post-inpact ball velocity of 15 mximl tennis serves per subject served as the and 300 degrees/second. functional performnce masuremnt. &asuremnt of post-inpact ball velocity was done by a GII radar gun, and RCA high speed video cara. Preliminary results show significantly greater dominant arm isokinetic strength for peak torque and single ‘Ihis strength difference was found to be (P,:.CO5) for shoulder internal repetition work using dependent T-tests. Differences of (P<.cOl) for shoulder extension and wrist extension rotation and flexion, as ~11 as wrist flexion. were also reported. No significant difference was found in shoulder external rotation and forearm supination. I4%an initial ball velocity measured by radar was 106 M.P.H. and did cot significantly correlate with any pattern of isokinetically treasured strength. mrther analysis will be done to determine if differences exist between Particular -hasis will be placed on the predictive ball velocity masured by radar and high speed video. capability radar ball velocity my have with respect to high speed video. Results from this investigation show unilaterally daninant rmscular strength in the racquet arm, as well as This data i-s imperative for design specific ratios of mscle strength surrounding joints of the upper extremity. of rehabilitative and rmscle conditioning programs for athletes in unilaterally dominant upper extremity sports.
BIOMECHANICAL CORRELATES OF FAST BOWLING AND BACK INJURIES IN CRICKET: A PROSPECTIVE STUDY David John, Tim Ackland and Ken Fitch Bruce Elliott, Daryl Foster, Department of Human Movement and Recreation Studies, The University of Western Australia, Perth, 6009, Australia Eighty-two high performance young male fast bowlers (mean age 16.8 years) were filmed both laterally (200 Hz) and from above (100 Hz), immediately prior to the season, while bowling such that their front foot impacted a force platform during the delivery stride. The players then completed a log book over the ensuing season, that detailed their training and playing programs. All cricket related injuries over this season were assessed by a sports physician, who used computerised tomography to assist in the diagnosis of spinal injuries. At the completion of this season players were grouped according to their injury status (Group 1 - bony injury to the spine: Group 2 - soft tissue injuries to the back that caused the player to miss at least one match and Group 3 - no injuries). Eleven percent of the players sustained a stress fracture to the vertebra(e) while 27% &tained a soft tissue injury to the back. Bowlers who excessively rotated the trunk to re-align the shoulders between back foot impact and front foot impact, were more likely to sustain back injuries. A greater release height was also significantly related to back injuries. No significant relationship was determined between peak vertical (5.4 BW) or horizontal (2.5 BW) GRF at front foot impact, however, these forces may predispose a bowler to back injuries if the person is required to bowl for long periods. Of the 32 subjects who bowled in more than the mean number of matches played, 19 sustained a stress fracture or back injury. Results suggest that bowling with these above charactistics particularly if done so for extended periods, may pre-dispose the young fast bowler to back injuries.
EFFECT OF FOOT Janice J. Eng and
ORTHOTICS
ON THE
KINEMATICS
OF THE
KNEE
JOINT
Michael R. Pierrynowski Hospital for Sick Children and Graduate Department of Community Health, University of Toronto, Toronto, Ontario, Canada. Three-dimensional (3D) kinematic analyses were performed to determine the effects of foot orthotics on the knee joint. Seven adolescent females, diagnosed with Patellofemoral Pain Syndrome (PFPS) and possessing forefoot varus greater than 10 degrees, were fitted with foot orthotics constructed from flat neoprene insoles and posted with medial rearfoot and forefoot wedges as required for each subject. Data was collected by a 4 camera optoelectronic system (WATSMART) at 75 Hz under 2 conditions: running shoe and flat neoprene insole, running shoe and orthotic. Two 20 s trials each of walking at 3.2 km/hr and running at 4.5 km/hr on a treadmill were recorded. Cycles were averaged over the 2 trials to allow inclusion of at least 27 gait cycles. In the sagittal plane, the orthotics did not produce any significant differences. In walking, significant differences were found in the transverse and frontal planes during the contact phase and in the frontal plane during the midstance phase. No significant differences were found in the propulsion phase in the frontal and transverse planes during walking. In running, significant differences were only found in the propulsion phase in the frontal and transverse planes. These results suggest that foot orthotics alter the biomechanics of the gait cycle in the transverse and frontal planes but their effect is different in walking and running. Further research the clinical effectiveness
is required
to compare
the biomechanical
of foot orthotics in the patient with PFPS.
results
achieved
with
orthotics
to
Society
of Biomechanics
XII
Congress
1007
1989
A 7btal Arm Strength Isokiwtic Profile of Highly Skilled Tennis Players and Its Relation to a Functional Perform Lincoln Institute for Athletic Medicine. Arizona State University ante Kwmemnt, Todd S. Ellenbecker, P.T., Departmnt of Exercise Science, Tenpe, Arizona U.S.A. Isokinetic testing of 22 male highly skilled tennis players was done using a Cybex II dyrmmeter and Li Tests wre conducted bilaterally for shoulder internal/ Discipline Rlll carputerized data reduction system. external rotation, flexion/extension, forearm pronation/supination and wrist flexion/extension at speeds of ‘%, 210 Initial post-inpact ball velocity of 15 mximl tennis serves per subject served as the and 300 degrees/second. functional performnce masuremnt. &asuremnt of post-inpact ball velocity was done by a GII radar gun, and RCA high speed video cara. Preliminary results show significantly greater dominant arm isokinetic strength for peak torque and single ‘Ihis strength difference was found to be (P,:.CO5) for shoulder internal repetition work using dependent T-tests. Differences of (P<.cOl) for shoulder extension and wrist extension rotation and flexion, as ~11 as wrist flexion. were also reported. No significant difference was found in shoulder external rotation and forearm supination. I4%an initial ball velocity measured by radar was 106 M.P.H. and did cot significantly correlate with any pattern of isokinetically treasured strength. mrther analysis will be done to determine if differences exist between Particular -hasis will be placed on the predictive ball velocity masured by radar and high speed video. capability radar ball velocity my have with respect to high speed video. Results from this investigation show unilaterally daninant rmscular strength in the racquet arm, as well as This data i-s imperative for design specific ratios of mscle strength surrounding joints of the upper extremity. of rehabilitative and rmscle conditioning programs for athletes in unilaterally dominant upper extremity sports.
BIOMECHANICAL CORRELATES OF FAST BOWLING AND BACK INJURIES IN CRICKET: A PROSPECTIVE STUDY David John, Tim Ackland and Ken Fitch Bruce Elliott, Daryl Foster, Department of Human Movement and Recreation Studies, The University of Western Australia, Perth, 6009, Australia Eighty-two high performance young male fast bowlers (mean age 16.8 years) were filmed both laterally (200 Hz) and from above (100 Hz), immediately prior to the season, while bowling such that their front foot impacted a force platform during the delivery stride. The players then completed a log book over the ensuing season, that detailed their training and playing programs. All cricket related injuries over this season were assessed by a sports physician, who used computerised tomography to assist in the diagnosis of spinal injuries. At the completion of this season players were grouped according to their injury status (Group 1 - bony injury to the spine: Group 2 - soft tissue injuries to the back that caused the player to miss at least one match and Group 3 - no injuries). Eleven percent of the players sustained a stress fracture to the vertebra(e) while 27% &tained a soft tissue injury to the back. Bowlers who excessively rotated the trunk to re-align the shoulders between back foot impact and front foot impact, were more likely to sustain back injuries. A greater release height was also significantly related to back injuries. No significant relationship was determined between peak vertical (5.4 BW) or horizontal (2.5 BW) GRF at front foot impact, however, these forces may predispose a bowler to back injuries if the person is required to bowl for long periods. Of the 32 subjects who bowled in more than the mean number of matches played, 19 sustained a stress fracture or back injury. Results suggest that bowling with these above charactistics particularly if done so for extended periods, may pre-dispose the young fast bowler to back injuries.
EFFECT OF FOOT Janice J. Eng and
ORTHOTICS
ON THE
KINEMATICS
OF THE
KNEE
JOINT
Michael R. Pierrynowski Hospital for Sick Children and Graduate Department of Community Health, University of Toronto, Toronto, Ontario, Canada. Three-dimensional (3D) kinematic analyses were performed to determine the effects of foot orthotics on the knee joint. Seven adolescent females, diagnosed with Patellofemoral Pain Syndrome (PFPS) and possessing forefoot varus greater than 10 degrees, were fitted with foot orthotics constructed from flat neoprene insoles and posted with medial rearfoot and forefoot wedges as required for each subject. Data was collected by a 4 camera optoelectronic system (WATSMART) at 75 Hz under 2 conditions: running shoe and flat neoprene insole, running shoe and orthotic. Two 20 s trials each of walking at 3.2 km/hr and running at 4.5 km/hr on a treadmill were recorded. Cycles were averaged over the 2 trials to allow inclusion of at least 27 gait cycles. In the sagittal plane, the orthotics did not produce any significant differences. In walking, significant differences were found in the transverse and frontal planes during the contact phase and in the frontal plane during the midstance phase. No significant differences were found in the propulsion phase in the frontal and transverse planes during walking. In running, significant differences were only found in the propulsion phase in the frontal and transverse planes. These results suggest that foot orthotics alter the biomechanics of the gait cycle in the transverse and frontal planes but their effect is different in walking and running. Further research the clinical effectiveness
is required
to compare
the biomechanical
of foot orthotics in the patient with PFPS.
results
achieved
with
orthotics
to