摘要:

AbstractTesting the capacity of the trunk extensor muscles may be useful in the diagnosis of low back pain. In the present study, the reproducibility of measurements of maximum trunk extension force, trunk extension endurance, and related electromyographic parameters was investigated. Intraclass correlations indicated that the reproducibility of maximum force and endurance time was satisfactory. Nevertheless, the smallest difference in these parameters that could be attributed, with 95% confidence, to a change in the condition of a patient was, in general, more than 20%. On the electromyograms, the slopes of amplitude and frequency content appeared to be related to endurance time. The reproducibility of these parameters in terms of the intraclass correlation was again satisfactory; however, the smallest detectable difference generally exceeded 50%. The clinical applicability of the parameters studied is severely limited by a lack of reproducibility.

ISSN:0736-0266    

DOI:10.1002/jor.1100140122

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractCrouch gait, one of the most common movement abnormalities among children with cerebral palsy, is characterized by persistent flexion of the knee during the stance phase. Short hamstrings are thought to be the cause of crouch gait; thus, crouch gait is often treated by surgical lengthening of the hamstrings. In this study, a graphics‐based model of the lower extremity was used in conjunction with three‐dimensional kinematic data obtained from gait analysis to estimate the lengths of the hamstrings and psoas muscles during normal and crouch gaits. Only three of 14 subjects with crouch gait (four of 20 limbs with knee flexion of 20° or more through stance) had hamstrings that were shorter than normal by more than 1 SD during walking. Most (80%) of the subjects with crouch gait had hamstrings of normal length or longer, despite persistent knee flexion during stance. This occurred because the excessive knee flexion was typically accompanied by excessive hip flexion throughout the gait cycle. All of the subjects with crouch gait had a psoas that was shorter than normal by more than 1 SD during walking. These results emphasize the need to consider the geometry and kinematics of multiple joints before performing surgical procedures aimed at correcting crouch

ISSN:0736-0266    

DOI:10.1002/jor.1100140123

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractDamage to the pulleys of the thumb flexor apparatus may cause bow‐stringing of the tendon and affect muscle function. An experiment using the hands and distal forearms of cadavers was designed to determine which damaged pulleys increase excursion length of the flexor tendon with constant tendon and resisting loads. Each specimen was mounted to a loading frame with a dead weight pinned to the tip of the thumb. The thumb flexor tendon was clamped to an actuator that applied a fixed load and measured excursion of the tendon. Ranges of motion of the thumb joint were also measured. The thumb flexor apparatus of each specimen was tested intact first, with the hand in flexed, neutral, and extended positions; then it was tested with progressive sectioning of pulleys from proximal to distal in one group and from distal to proximal in a second group. The length of excursion increased significantly with all pulleys cut but there was no effect on on overall range of motion of the thumb. With proximal to distal sectioning, no change in tendon excursion occurred when the flexor retinaculum and the first annular pulleys were cut, until the oblique pulley was sectioned, leadving only the second annular pulley intact (range, 1.17–1.31 times that of intact excursion, dependent on position of the hand). With distal to proximal sectioning, tendon excursion was not affected when the second annular and oblique pulleys were cut but did increase when the first annular pulley was sectioned, leaving only the flexor retinaculum intact (range, 1.28–1.36 times that of intact excursion). Dependent on the location of damage, therefore, an intact oblique or first annular pulley can maintain normal excursion of the t

ISSN:0736-0266    

DOI:10.1002/jor.1100140124

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe effects of stress deprivation on the mechanical properties of the anterior cruciate ligament were studied in a canine model. Fifty‐eight mature mongrel dogs were divided into two groups. In the relaxed group (n = 30), the tibial insertion of the anterior cruciate ligament in each right knee was surgically elevated proximally 3 mm from the tibia: the elevation was anatomically reduced in the sham group (n = 28). In order to obtain control data, the left knee in each dog was left untreated. A femur‐anterior cruciate ligament‐tibia complex was excised from each knee for biomechanical tests at 6 or 12 weeks after surgery. To simplify data analysis, the treat/nontreat ratio (the ratio of the data obtained from the treated knee to that from the nontreated knee) was used. The cross‐sectional area of the ligament increased significantly in both groups; the area in the relaxed group (average treat/nontreat ratio = 1.37) was significantly larger than that in the sham group (1.16) at 6 weeks but not at 12 weeks. The treat/nontreat ratio of tensile strength in the relaxed group significantly decreased to 0.67 and 0.58 at 6 and 12 weeks, respectively: in the sham group, it significantly decreased to 0.79 at 6 weeks but subsequently increased to 0.87 at 12 weeks. Only at 12 weeks was a significant difference observed between the two groups. This study demonstrated that, in the anterior cruciate ligament, stress deprivation results in a rapid increase in the cross‐sectional area, although this effect disappears by 12 weeks, and in a decrease in mechanical strength, although a relatively long period of more than 6 weeks is required for the dete

ISSN:0736-0266    

DOI:10.1002/jor.1100140125

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

ISSN:0736-0266    

DOI:10.1002/jor.1100140126

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

ISSN:0736-0266    

DOI:10.1002/jor.1100140127

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

ISSN:0736-0266    

DOI:10.1002/jor.1100140101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY