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Grip strength and forearm straps in tennis elbow
114
C/in. Biomech. 1986;
1: No 2
The hands of karate experts. Clinical and radiological tindings The hands and wrists of 22 karate instructors who had practiced the sport for a minimum of five years were reviewed. Radiological evidence of a total of ten fractures was found. There was no evidence that practice of the sport predisposed to the early onset of chronic tenosynovitis or osteoarthritis. Crosby AC.
Br J Sports Med 1985; 19: 41-2
Grip strength and forearm straps in tennis elbow Twenty-seven patients who presented with tennis elbow had their grip strengths measured without a forearm strap, with an elastic strap and with an inelastic strap. Of these 85% displayed an increased pain-free grip strength with one or both straps. The increase in pain-free grip strength was statistically significant for both types of strap (P
AK.
Br J Sports Med 1985; 19: 37-8
Isokinetic shoulder strength of high school and collegeaged pitchers The purpose of this study was to determine the isokinetic strength of the shoulders of high school and college-aged baseball pitchers. Twenty-four athletes ranging from 14 to 21 years of age volunteered for this study. The Cybex@ II and U.B.X.T. were utilized to test the strength of the shoulder abductorsladductors, flexors/extensors. horizontal abductors/ adductors, and external/internal rotators at 90,120.210. and 3OO”/sec. There were no consistent differences between dominant and nondominant arm strength, except for the shoulder adductors and shoulder extensors. The shoulder abductors and flexors were approximately 50% as strong as the adductors and extensors, respectively. There was a 1: 1 ratio between the horizontal abductors/adductors. The external rotators were approximately two-thirds as strong as the internal rotators. A positive correlation was found between total body weight and shoulder strength. This information is relatively new to the literature and should provide clinicians with some training and rehabilitation guidelines. Alderink, 163-72
GJ, Kuck DJ. J Orthop
Sports Phys Ther
1986; 7:
BIOMECHANICS Gradual disc prolapse
MA,
Hutton
WC.
The forces induced in the disc and ligaments of a lumhar motion segment in resisting a quasi-static external load. using a semi-experimental approach. are presented. The lines of action of ligaments (direction cosines) and disc center for the initial position of the specimen were determined using a morphometer. The changes in these lines of action for a known external load were computed by using the threedimensional load-deformation characteristics of an intact motion segment. The load-deformation behavior were obtained by applying a known load to the motion segment’s superior vertebra and recording the motion produced. A seven dial gauge motion measuring system was used for this purpose. The six equations of equilibrium yielded a statically indeterminate model. A linear optimization technique in conjunction with a cost function enabled the computation of forces in the ligaments as well as forces and moments in the disc. This approach made it possible to determine the component forces without a priori knowledge of the structural properties of ligaments. Typically for an external flexion moment of 6.9 Nm the supraspinous ligament experienced the most force (60N). followed hy capsular ligaments (25 N). and transverse ligaments (15 N). A compressive force of IO0 N within the disc was predicted. The load-deformation curve. obtained from this study. for the supraspinous ligament was nonlinear and is in agreement with puhlished experimental results. Gorl VK. Fromknecht SJ. Nishiyama YK. Spine 1985; 10: 516-Z
Spine 1985; 10: 52431
K, Weinstein
J. Liu
Shoulder externally rotating exercises with pulley apparatus-joint load and EMG The mechanical load on the gleno-humeral joint and the muscular activity during shoulder external rotation resisted h! ;I pulley apparatus were analysed using normalized. lowp;ls+tiltcrcd EMG recorded from the infraspinatuh. deltoid. pccfor;llis m;lior and trapczius muscles. The load moment ahout the tonritudinat axis of the joint was compared with the dl\tribution 01 m;tsimum muscle moment over different ;~nglc\ throughout the range of motion. The effect of subject po4itloning (111the joint loxi and the muscular activity was studied. The heat adaptation hctwecn the curve5 for load moment ;~ntl m;lximum muscle moment was obtained when ihe \uhject H’;IS positioned sitting with the pulley located 20 dcgrceh poatcrior to ;I frontal plane through the shoulders at ;I distance of I.3 m from the joint. Of the four muscles Investigated. the infraspinatus was the most active. The method dcscrihed might he used to find optimal designs of hhoutdcr external rotation exercises with special regard to avoiding unintentional overloading of joint structures weakened hy disease or trauma. tlarms-Ringdahl
Fifty-two cadaveric lumbar motion segments were subjected to fatigue loading in compression and bending to determine if the intervertebral discs could prolapse in a gradual manner. Prior to testing. the nucleus pulposus of each disc was stained with a small quantity of blue dye and radiopaque solution. This,enabled the progress of any gradual prolapse to he monitored by direct observation and by discogram. Six discs developed a gradual prolapse during the testing period. The injury starts with the lamellae of the annulus being distorted to form radial fissures and then nuclear pulp is extruded from the disc and leaks into the spinal canal. Discs most commonly affected were from the lower lumbar spine of young cadavers. Tests on ten older discs with pre-existing ruptures showed that such discs are stable and do not leak nuclear pulp. Adams
The role of lumbar spinal elements in flexion
Schiildt
K. Arhorelius
K. Stand J Rehab
Med
UP, Ekholm
J. Nemeth
G.
1985; 17: 12wO
Experimental measurement of rotatory and translatory instability of the knee joint In the evaluation and treatment of knee ligament injuries and for comprehensive understanding of knee ligament function, it is important to know where in the movement of extensionflexion the different types of instability released by wellknown ligament injuries occur. An apparatus was developed to record anterior-posterior tibia1 displacement, valgus-varus instahility, and axial tibia1 rotation instability on knee preparations, continuously, in the extension-flexion movement. when the tibia was submitted to a well-delined constant torque or force. Osteoligamentous knee
C/in. Biomech. 1986;
1: No 2
The hands of karate experts. Clinical and radiological tindings The hands and wrists of 22 karate instructors who had practiced the sport for a minimum of five years were reviewed. Radiological evidence of a total of ten fractures was found. There was no evidence that practice of the sport predisposed to the early onset of chronic tenosynovitis or osteoarthritis. Crosby AC.
Br J Sports Med 1985; 19: 41-2
Grip strength and forearm straps in tennis elbow Twenty-seven patients who presented with tennis elbow had their grip strengths measured without a forearm strap, with an elastic strap and with an inelastic strap. Of these 85% displayed an increased pain-free grip strength with one or both straps. The increase in pain-free grip strength was statistically significant for both types of strap (P
AK.
Br J Sports Med 1985; 19: 37-8
Isokinetic shoulder strength of high school and collegeaged pitchers The purpose of this study was to determine the isokinetic strength of the shoulders of high school and college-aged baseball pitchers. Twenty-four athletes ranging from 14 to 21 years of age volunteered for this study. The Cybex@ II and U.B.X.T. were utilized to test the strength of the shoulder abductorsladductors, flexors/extensors. horizontal abductors/ adductors, and external/internal rotators at 90,120.210. and 3OO”/sec. There were no consistent differences between dominant and nondominant arm strength, except for the shoulder adductors and shoulder extensors. The shoulder abductors and flexors were approximately 50% as strong as the adductors and extensors, respectively. There was a 1: 1 ratio between the horizontal abductors/adductors. The external rotators were approximately two-thirds as strong as the internal rotators. A positive correlation was found between total body weight and shoulder strength. This information is relatively new to the literature and should provide clinicians with some training and rehabilitation guidelines. Alderink, 163-72
GJ, Kuck DJ. J Orthop
Sports Phys Ther
1986; 7:
BIOMECHANICS Gradual disc prolapse
MA,
Hutton
WC.
The forces induced in the disc and ligaments of a lumhar motion segment in resisting a quasi-static external load. using a semi-experimental approach. are presented. The lines of action of ligaments (direction cosines) and disc center for the initial position of the specimen were determined using a morphometer. The changes in these lines of action for a known external load were computed by using the threedimensional load-deformation characteristics of an intact motion segment. The load-deformation behavior were obtained by applying a known load to the motion segment’s superior vertebra and recording the motion produced. A seven dial gauge motion measuring system was used for this purpose. The six equations of equilibrium yielded a statically indeterminate model. A linear optimization technique in conjunction with a cost function enabled the computation of forces in the ligaments as well as forces and moments in the disc. This approach made it possible to determine the component forces without a priori knowledge of the structural properties of ligaments. Typically for an external flexion moment of 6.9 Nm the supraspinous ligament experienced the most force (60N). followed hy capsular ligaments (25 N). and transverse ligaments (15 N). A compressive force of IO0 N within the disc was predicted. The load-deformation curve. obtained from this study. for the supraspinous ligament was nonlinear and is in agreement with puhlished experimental results. Gorl VK. Fromknecht SJ. Nishiyama YK. Spine 1985; 10: 516-Z
Spine 1985; 10: 52431
K, Weinstein
J. Liu
Shoulder externally rotating exercises with pulley apparatus-joint load and EMG The mechanical load on the gleno-humeral joint and the muscular activity during shoulder external rotation resisted h! ;I pulley apparatus were analysed using normalized. lowp;ls+tiltcrcd EMG recorded from the infraspinatuh. deltoid. pccfor;llis m;lior and trapczius muscles. The load moment ahout the tonritudinat axis of the joint was compared with the dl\tribution 01 m;tsimum muscle moment over different ;~nglc\ throughout the range of motion. The effect of subject po4itloning (111the joint loxi and the muscular activity was studied. The heat adaptation hctwecn the curve5 for load moment ;~ntl m;lximum muscle moment was obtained when ihe \uhject H’;IS positioned sitting with the pulley located 20 dcgrceh poatcrior to ;I frontal plane through the shoulders at ;I distance of I.3 m from the joint. Of the four muscles Investigated. the infraspinatus was the most active. The method dcscrihed might he used to find optimal designs of hhoutdcr external rotation exercises with special regard to avoiding unintentional overloading of joint structures weakened hy disease or trauma. tlarms-Ringdahl
Fifty-two cadaveric lumbar motion segments were subjected to fatigue loading in compression and bending to determine if the intervertebral discs could prolapse in a gradual manner. Prior to testing. the nucleus pulposus of each disc was stained with a small quantity of blue dye and radiopaque solution. This,enabled the progress of any gradual prolapse to he monitored by direct observation and by discogram. Six discs developed a gradual prolapse during the testing period. The injury starts with the lamellae of the annulus being distorted to form radial fissures and then nuclear pulp is extruded from the disc and leaks into the spinal canal. Discs most commonly affected were from the lower lumbar spine of young cadavers. Tests on ten older discs with pre-existing ruptures showed that such discs are stable and do not leak nuclear pulp. Adams
The role of lumbar spinal elements in flexion
Schiildt
K. Arhorelius
K. Stand J Rehab
Med
UP, Ekholm
J. Nemeth
G.
1985; 17: 12wO
Experimental measurement of rotatory and translatory instability of the knee joint In the evaluation and treatment of knee ligament injuries and for comprehensive understanding of knee ligament function, it is important to know where in the movement of extensionflexion the different types of instability released by wellknown ligament injuries occur. An apparatus was developed to record anterior-posterior tibia1 displacement, valgus-varus instahility, and axial tibia1 rotation instability on knee preparations, continuously, in the extension-flexion movement. when the tibia was submitted to a well-delined constant torque or force. Osteoligamentous knee