Understanding the afferent neural system of the knee is considered to be vital to rehabilitation planning. An intricate relationship exists involving the afferent neural receptors in the inert and contractile tissues of the knee. Traditional rehabilitation strategies may not exploit this extensive afferent neural system. Closed kinetic chain functional training (CKCFT) may provide a method for more effectively rehabilitating an injured or reconstructed knee. The rationale for CKCFT has traditionally focused on mechanical aspects. Sensorimotor integration through motor learning is believed to be an important component of CKCFT. The purposes of this review are to discuss: 1) the afferent neural system of the knee with emphasis on the mechanoreceptors, 2) the influence of the afferent neural system of the knee on motor learning, and 3) how CKCFT uses the afferent neural system of the knee and motor learning during knee rehabilitation. This review reinforces the use of CKCFT in knee rehabilitation plans.

J Orthop Sports Phys Ther. 1994;19(1):2-11.

Key Words: articular neurology, motor learning, knee rehabilitation

Physical therapists commonly treat patients when knowledge of percent weight bearing is desirable during functional lower extremity exercise. The purpose of this study was to compare 2 methods for calculating percent body weight at different angles of inclination on a tilt table. Twenty healthy subjects were weighed on a spring scale in standing and on a tilt table at 5° increments between 0° and 90° of tilt. Percent body weight at each angle was compared to a value predicted from a trigonometric equation. Predicted values were significantly greater than measured values at all angles greater than 10° of tilt. Predicted overestimation ranged from 2.8% to 14.2%. Compared to the trigonometric method, physical therapists can more easily and accurately determine percent body weight on a tilt table using a scale if total body weight is known. Partial weight-bearing rehabilitation could be performed on the tilt table by varying the degree of inclination, allowing functional lower extremity exercise for patients with weight-bearing restrictions. Guidelines could be established following a variety of injuries and orthopaedic procedures incorporating functional lower extremity exercises at varying percentages of body weight.

J Orthop Sports Phys Ther. 1994;19(1):18-21.

Key Words: percent body weight, tilt table

The assessment of muscle strength is a task performed frequently by physical therapists. The purposes of this study were to determine whether intrasession test-retest reliability differs between make and break tests and strength tests that do not require an assessor (eg, isometric Kin-Com test) and hand-held dynamometer (HHD) assessments. The elbow flexor strength of 32 healthy, female volunteers was measured under 4 test conditions: Kin-Com make and break, and HHD make and break. Two measurements were performed for each test condition by the same rater. The results showed: 1) measurements obtained using the HHD deviated from a normal distribution, 2) comparable reliability coefficients for the make and break tests were obtained from the Kin-Com device, 3) there was a higher reliability coefficient for the make test compared with the break test for the HHD tests, and 4) the measured forces for the break tests were higher than the make tests. The results support the premise that hand-held dynamometry is a viable alternative to more costly modes of isometric strength measurements, provided the assessor's strength is greater than that of the specific muscle group being measured.

J Orthop Sports Phys Ther. 1994;19(1):28-32.

Key Words: muscle strength, measurement, methods

There is substantial reason to believe that asymmetry of trunk motion plays a significant role in the development and presentation of low back pain. However, there has been little review of objective measurements of low back pain and asymptomatic populations to support these assumptions or the related clinical models. In order to study asymmetry of trunk function and its relationship to the presence of low back pain and laterality of symptoms, 120 subjects with low back pain (LBP) and 168 subjects without low back pain (NLBP) were tested for rotation and lateral flexion, active range of motion (ROM), and isometric strength using the B-200 Lumbar Dynamometer. A similar pattern of asymmetry was found in both NLBP and LBP populations; however, the magnitude of ROM asymmetry was significantly greater for the LBP subjects (p<.005). There was also a positive relationship between ROM magnitude of asymmetry and intratest variance in LBP subjects that was not evident in NLBP subjects. No relationships were found between isometric strength measures and LBP or between laterality of asymmetric function and laterality of radiating symptoms. The asymmetry observed in the LBP population may be an augmented expression of normal asymmetrical performance, and behavioral factors may play a role in this expression. These observations may influence our use of lumbar function asymmetry as an objective clinical sign relating to specific pathological processes.

J Orthop Sports Phys Ther. 1994;19(1):42-48.

Key Words: low back pain, trunk function, lumbar symmetry