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Radiographic verification of knee goniometry
58
C/in. Biomech. 1987; 2: No 1
Mounting of the transducers in measurement of segmental motion of the spine A seated female subject was subjected to sinusoidal whole body vibration at 2,4, 5 and 6 Hz. Accelerations were measured by accelerometers on pins screwed into the spinous process. The pins were also fitted with light emitting diodes (LED). The displacement of these LEDs were compared to LEDs attached directly to the skin. Substantial differences in measured displacements were noted between surface mounted LEDs and those mounted on pins rigidly attached to the skeleton. These differences were more marked further out from the center line. Pope MH, Svensson M, Broman H, Andersson J Biomech 1986; 19; 675-7
GBJ.
Effect of muscular activity on valgus/varus laxity and stiffness of the knee Quantitative changes in valgus/varus knee stability with different levels of muscular activity were determined for five subjects. A specially designed machine was used to measure resistance to angulation in the frontal plane. This device held the thigh stationary, the knee straight, and cycled the leg from side to side at a constant rate between present moment limits. Resisfance to this forced valgus/varus motion was measured simultaneously with torque about the knee in the sagittal plane. Muscle activity was monitored by electromyography (EMG). Direct comparison of momentrotation characteristics allowed changes in stability to be quantified as a function of extension and flexion torque. Extension torques less than 20% of the maximum increased varus stability more than valgus stability. Flexion torques of the same relative magnitude increased valgus stability more than varus stability. Comparison with the literature suggested that prevention of opening of the lateral side of the joint under varus loading was responsible for increased varus stability with increasing torque, both with extension and flexion torques. Olmstead TG, Wevers HW, Bryant JT, Gouw GJ. J Biomech 1986; 19: 565-77
Radiographic verification of knee goniometry The accuracy of knee goniometry was examined by comparing goniometric measurements with radiographic bone angle measurements of six positions of the knee, namely, 0”. 15”, 30”, 45”, 60”, and 90”. With the first 15”of knee flexion joint excursion measured by goniometry differed significantly from bone angle measurement (pCO.01). With 30” of knee flexion or more, no significant difference was found between goniometric measurements and bone angle measurements of knee motion. These findings suggest that within the first 15”of knee flexion. goniometric measurement of joint excursion may be remarkably wrong. On account of this, it was suggested that when range of motion is limited at the knee joint, caution should be exercised in determining movement gains or losses within the initial 15”of knee flexion. Enwemeka
CS. Stand J Rehab Med 1986; 18: 47-9
Changes in muscle activity during fast, alternating flexion-extension movements of the knee The effects of high frequency alternating knee flexionextension on muscle activity of the quadriceps and hamstring muscle groups has been investigated. Standard loads were used for each subject. The muscle activity in vastus medialis,
vastus lateralis, rectus femoris and the lateral hamstrings were recorded by electromyography during increasing velocities. Rectus femoris and hamstrings were found to increase their activities significantly with increasing speed while vastus medialis and vastus lateralis showed no such change. The individual thigh muscles thus differ in function in relation to the velocity of movement. Richardson C, Bullock MI. Stand J Rehab Med 1986; 18: 51-8
Mechanism of active expiration in tetraplegic subjects Traumatic tetraplegia produces paralysis of all the wellrecognized muscles of expiration. Yet, tetraplegic subjects usually have a small expiratory reserve volume on spirographic examination. To understand the mechanism that enables these patients to empty their lungs actively, we studied the pattern of chest-wall motion during voluntary expiration. We found negligible changes in abdominal dimension, but all subjects had a marked and reproducible decrease in the dimension of the upper rib cage. Electrical measurements established that the subjects had active use of the clavicular portion of the pectoralis major, and changing the orientation of these muscle fibers by maintaining the shoulders in abduction reduced their expiratory reserve volume by about 60 percent (P
The rheology of joints. Heberden oration 1985 The value of rheological studies of joint tissues has been illustrated by studies from our department. These have included studies of the stiffness of joints which suggest that subjective stiffness is more likely to be related to limitation of movement of a joint than to increased physical stiffness (either elastic or dissipative torques). A review of goniometry suggests that the diminution of joint movement with advancing age varies with the frequency of use of the joint. A simple goniometer for the hip has been described, and in contrast a sophisticated telemeterized system has been devised. Instruments to measure passive movement of joints, and their application for hypermobility, have been discussed. A knee analyser has been constructed to measure ligamentous and meniscal damage. Ligament replacement has been successfu1ly achieved in the pig and in man by using a woven polyester tube. The load-bearing function of the menisci has been clearly demonstrated, explaining the relationship found in studies of parachutists and physicaleducation teachers between meniscectomy and osteoarthrosis of the knee. Support for the Leeds biomechanical hypothesis for the development of osteoarthrosis has been described from rheological studies of cartilage at the patellofemorai joint and at the ankle. The intervertebral joint does not appear to be a shock absorber in compression. The spine must bend to function in this way. The relevance to rigid segments of the spondylitic spine and surgical fusion of vertebrae is discussed. Wright V. Br J Rheumatoll986;
25: 243-52
C/in. Biomech. 1987; 2: No 1
Mounting of the transducers in measurement of segmental motion of the spine A seated female subject was subjected to sinusoidal whole body vibration at 2,4, 5 and 6 Hz. Accelerations were measured by accelerometers on pins screwed into the spinous process. The pins were also fitted with light emitting diodes (LED). The displacement of these LEDs were compared to LEDs attached directly to the skin. Substantial differences in measured displacements were noted between surface mounted LEDs and those mounted on pins rigidly attached to the skeleton. These differences were more marked further out from the center line. Pope MH, Svensson M, Broman H, Andersson J Biomech 1986; 19; 675-7
GBJ.
Effect of muscular activity on valgus/varus laxity and stiffness of the knee Quantitative changes in valgus/varus knee stability with different levels of muscular activity were determined for five subjects. A specially designed machine was used to measure resistance to angulation in the frontal plane. This device held the thigh stationary, the knee straight, and cycled the leg from side to side at a constant rate between present moment limits. Resisfance to this forced valgus/varus motion was measured simultaneously with torque about the knee in the sagittal plane. Muscle activity was monitored by electromyography (EMG). Direct comparison of momentrotation characteristics allowed changes in stability to be quantified as a function of extension and flexion torque. Extension torques less than 20% of the maximum increased varus stability more than valgus stability. Flexion torques of the same relative magnitude increased valgus stability more than varus stability. Comparison with the literature suggested that prevention of opening of the lateral side of the joint under varus loading was responsible for increased varus stability with increasing torque, both with extension and flexion torques. Olmstead TG, Wevers HW, Bryant JT, Gouw GJ. J Biomech 1986; 19: 565-77
Radiographic verification of knee goniometry The accuracy of knee goniometry was examined by comparing goniometric measurements with radiographic bone angle measurements of six positions of the knee, namely, 0”. 15”, 30”, 45”, 60”, and 90”. With the first 15”of knee flexion joint excursion measured by goniometry differed significantly from bone angle measurement (pCO.01). With 30” of knee flexion or more, no significant difference was found between goniometric measurements and bone angle measurements of knee motion. These findings suggest that within the first 15”of knee flexion. goniometric measurement of joint excursion may be remarkably wrong. On account of this, it was suggested that when range of motion is limited at the knee joint, caution should be exercised in determining movement gains or losses within the initial 15”of knee flexion. Enwemeka
CS. Stand J Rehab Med 1986; 18: 47-9
Changes in muscle activity during fast, alternating flexion-extension movements of the knee The effects of high frequency alternating knee flexionextension on muscle activity of the quadriceps and hamstring muscle groups has been investigated. Standard loads were used for each subject. The muscle activity in vastus medialis,
vastus lateralis, rectus femoris and the lateral hamstrings were recorded by electromyography during increasing velocities. Rectus femoris and hamstrings were found to increase their activities significantly with increasing speed while vastus medialis and vastus lateralis showed no such change. The individual thigh muscles thus differ in function in relation to the velocity of movement. Richardson C, Bullock MI. Stand J Rehab Med 1986; 18: 51-8
Mechanism of active expiration in tetraplegic subjects Traumatic tetraplegia produces paralysis of all the wellrecognized muscles of expiration. Yet, tetraplegic subjects usually have a small expiratory reserve volume on spirographic examination. To understand the mechanism that enables these patients to empty their lungs actively, we studied the pattern of chest-wall motion during voluntary expiration. We found negligible changes in abdominal dimension, but all subjects had a marked and reproducible decrease in the dimension of the upper rib cage. Electrical measurements established that the subjects had active use of the clavicular portion of the pectoralis major, and changing the orientation of these muscle fibers by maintaining the shoulders in abduction reduced their expiratory reserve volume by about 60 percent (P
The rheology of joints. Heberden oration 1985 The value of rheological studies of joint tissues has been illustrated by studies from our department. These have included studies of the stiffness of joints which suggest that subjective stiffness is more likely to be related to limitation of movement of a joint than to increased physical stiffness (either elastic or dissipative torques). A review of goniometry suggests that the diminution of joint movement with advancing age varies with the frequency of use of the joint. A simple goniometer for the hip has been described, and in contrast a sophisticated telemeterized system has been devised. Instruments to measure passive movement of joints, and their application for hypermobility, have been discussed. A knee analyser has been constructed to measure ligamentous and meniscal damage. Ligament replacement has been successfu1ly achieved in the pig and in man by using a woven polyester tube. The load-bearing function of the menisci has been clearly demonstrated, explaining the relationship found in studies of parachutists and physicaleducation teachers between meniscectomy and osteoarthrosis of the knee. Support for the Leeds biomechanical hypothesis for the development of osteoarthrosis has been described from rheological studies of cartilage at the patellofemorai joint and at the ankle. The intervertebral joint does not appear to be a shock absorber in compression. The spine must bend to function in this way. The relevance to rigid segments of the spondylitic spine and surgical fusion of vertebrae is discussed. Wright V. Br J Rheumatoll986;
25: 243-52