[Stiffness of rotation of the forearm associated with contraction of the membrana interossea antebrachii (animal experiments) (author's transl)]

In 18 adult cats a wedge osteotomy in the middle of the radial shaft was performed and stabilized with plate fixation in 10 degrees axial deviation. After different times of survival forearm specimens were obtained. In a motion-simulator the elongation pattern of the interosseous membrane during pronation and supination was measured with strain gauges. Remarkable changes of the normal elongation pattern could be observed according to the deviation of the radius.

Effect of spinal cord transection on neuromuscular function in the rat

The effect of T6 spinal cord transection on neuromuscular physiology, pharmacology, and histochemistry as well as succinylcholine-induced changes in serum potassium were studied in 88 Sprague-Dawley rats and compared to 19 control animals. Resting membrane potential of spinal cord transected animals decreased by a maximum of 15 mV. This change was significant at days 3, 7, and 30 posttransection. Cell membrane input resistance was significantly decreased at posttransection days 10 and 15. Succinylcholine-induced contracture increased 3- to 4-fold and was significantly greater than control values on days 5 and 10 posttransection. Concomitant with the development of contracture there was a spread of cholinergic receptor from the end plate region. This differed from control acetylcholine sensitivity on days 7, 15, and 30 when receptor could be detected in excess of 1000 micrometer from the endplate. Serum K+ levels 3 min after administration of succinylcholine (1 mg/kg) was significantly elevated on days 10 and 30. Spinal cord transection causes denervation-like changes in the involved skeletal muscle.

Myocardial contracture: the predominant causes of impeded reperfusion in simulated surgical ischemia

"Worst-case" surgical conditions were simulated using the isolated model of a parabiotically perfused rabbit heart septum. Such conditions occur clinically in regional myocardium distal to stenosed coronary arteries and are characterized by inadequate or absent ionic influence on the myocardium by chemical cardioplegia and equilibration to room temperature. This study tested the hypothesis that ischemic contracture, rather than intracellular or extracellular edema, critical closing or delayed critical opening, was the predominant cause of impeded reperfusion that damages myocardium. In 20 reperfused ischemic septa, conductance (flow per unit pressure) decreased significantly (P less than 0.05) as ischemia at 24 degrees C was prolonged from 15 to 90 minutes and as contracture became more severe. Conductance was not decreased significantly by even large amounts of extracellular edema. Intracellular edema did not occur. In 17 normal septa, the critical closing pressure was 9.3 mm Hg. Critical opening pressures following 5 to 90 minutes ischemia at 24 degrees C did not differ significantly. Although early reflow was impeded progressively with longer ischemic intervals, it was not significant as was due to contracture rather than critical closing or delayed critical opening. This study confirmed the hypothesis that contracture is the predominant cause of impeded reperfusion in simulated surgical ischemia.

Contractures of the quadriceps and hamstring muscles in healthy male adult

We studied the extensibility of the quadriceps muscle and the hamstring muscles in 822 healthy male adults. 1) Extensibility of the quadriceps muscle The average angle of the buttock elevation phenomenon (B.E.P.) was 124.0 degrees +/- 16.71 on the right leg and 122.2 degrees +/- 19.75 on the left leg. And the contracture of the quadriceps (B.E.P. less than or equal to 100 degrees) was found in 16.1% of them. 2) Extensibility of the hamstring muscles The average angle of the straight leg raising test (S.L.R.) was 79.3 degrees +/- 9.56 on the right leg and 79.9 degrees +/- 9.56 on the left leg. And the contracture of the hamstrings (S.L.R. less than 70 degrees) was found in 10.3% of them.

Rotatory contracture of the forearm

We saw seven patients with an idiopathic progressive loss of rotation of the forearm, occurring primarily during adolescence and manifested principally by a gradual loss of supination. There were secondary developmental abnormalities of the radial head and of the ulna (distal bowing) in four patients. Six surgical procedures were performed on five of the seven patients, consisting of combinations of sectioning of the quadrate ligament, release of the interosseous membrane, and ostecotomy and compression-plate fixation of the distal end of the ulna. There was functional improvement in four patients. Release of the quadrate ligament provided the greatest improvement, but that release alone was of minimum value. We concluded that a contracted quadrate ligament may be an important deterrent to supination of the forearm, but distortion of the radial head, curvature of the ulna, and contracted soft tissues in the interosseus space and distal radio-ulnar joint also are contributory factors.

Neurological and pharmacological evaluation of a case of stiff-man syndrome

A typical case of stiff-man syndrome was studied neurophysiologically and pharmacologically focusing the attention on a central disorder, either spinal or suprasegmental. The results support the hypothesis that a gamma type of hypertonia is one of the causes of the stiff-man syndrome, ruling out the participation of the Renshaw circuits. The syndrome should be considered a central disorder of the descending pathways that control and modify gamma activity and the startle reaction mechanisms, especially affecting the circuits that use Gabaergic mediators.

Turnbuckle orthotic correction of elbow-flexion contractures after acute injuries

Fifteen patients with acute flexion contractures of the elbow after injuries or operations were treated with a turnbuckle splint. Satisfactory correction was achieved in twelve patients. An average reduction in deformity of about 37 degrees was recorded after an average treatment period of twenty weeks. The treatment was unsuccessful in three patients with severe intra-articular damage because the splint caused excessive discomfort. The average improvement in the arc of motion of the elbow was approximately 43 degrees.

Mechanical and structural correlates of contracture induced by metabolic blockade in cardiac muscle from the rat

We performed morphological studies of myocardial contracture to define its nature and relationship to mechanical changes occurring during metabolic blockade. Isolated rat papillary and trabecular muscles were stretched to the apices of their length-tension curves and stimulated to contract isometrically 12 times a minute at a temperature of 28 degrees C. Incomplete and total metabolic blockade were induced by 1 hour of hypoxia (95% N2, 5% CO2) or by hypoxia plus glycolytic blockade with iodoacetic acid, 10-4M, respectively. In oxygenated control preparations, mechanical performance was stable for the 60-minute experimental period. In preparations exposed to hypoxia, developed tension fell to 7 +/- 2% of prehypoxia values at 60 minutes. Contracture tension increased progressively to 2.5 +/- 0.4 g/mm2. With total metabolic blockade, developed tension declined to zero by 10 minutes, contracture tension rose to an average peak value of 5.3 +/- 0.4 g/mm2 by 15 minutes, and subsequently slowly declined. All preparations were fixed at Lmax in the muscle bath. Light and electron microscopic studies revealed focal irregularities of A, I, and Z bands with sarcomere malalignment, hypercontraction, and fiber disruption, which increased in severity with increasing metabolic blockade. Linear densities appeared in mitochondria following total metabolic blockade, but mitochondria appeared normal otherwise. Thus, myocardial contracture after metabolic blockade is a focal process beginning within the sarcomere; morphological alterations in the contractile apparatus correlate with mechanical changes and are more severe than those in the mitochondria.

Lengthening of the elbow flexors in cerebral palsy

A procedure has been devised for treatment of the inability to extend the elbow due to either a fixed contracture of the flexor muscles or increased involuntary flexor-muscle tone and spasticity. The operation consists of lengthening all of the primary elbow-flexor muscles. It has been used successfully in thirty-two elbows of twenty-six children with cerebral palsy who were followed for an average of four years (range, two through six years). The average gain in extension was 40 degrees, and there was no loss of the patient's ability to flex the elbow or supinate the forearm. No vascular or neural complications were encountered. Independence in feeding was achieved in four patients. Seven patient acquired the ability to engage in sports and six, who previously had been unable to walk independently due to inability to handle crutches, could do so following this procedure.

Gastrocnemius muscle belly and tendon length in stroke patients and able-bodied persons

Length changes of gastrocnemius muscle belly and tendon at different passive tensions and ranges of motion (ROM) were measured in 31 healthy persons and 15 hemiplegic patients with clinically demonstrated ankle joint plantar flexion (PF) contractures. Preliminary studies were done to obtain accurate determination of gastrocnemius muscle insertion and origin points on x-ray films, to calculate the magnification factor due to x-ray beam divergence and to measure the length changes in muscle belly by the use of a wire hook placed at the muscle-tendon junction. Our results revealed: (1) change in length at different passive tensions is in the muscle belly, not in the tendon, (2) in hemiplegic patients no statistical difference in elongational characteristics of affected gastrocnemius muscle bellies with clinically demonstrated ankle PF contractures and of the contralateral nonaffected muscle bellies, (3) spastic and flaccid gastrocnemius muscle bellies are not statistically different in respect to passive elongations, (4) gastrocnemius muscle bellies of both affected and nonaffected legs of hemiplegic patients were statistically different from the muscle bellies of healthy persons in regard to maximal ROM and maxinum muscle belly length changes, (5) there was approximately .5 mm change in the belly length for each degree of ankle ROM, (6) age is not a factor influencing passive elongation of muscle belly, (7) average muscle belly lengths were consistently shorter in hemiplegic muscles while their tendon lengths did not change. The enumerated findings suggest that the limitation of ankle ROM in spastic hemiplegic legs obtained by the standard clinical measurements technique represents a change in muscle belly rest length without a structural contracture of the muscle fibers.