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At least 19 recordsLinked to original sources
PubMed1988

Comparison of pronator tenotomy and pronator rerouting in children with spastic cerebral palsy.

Forty-one patients with cerebral palsy and pronation contracture of the forearm were treated with pronator teres rerouting compared with 16 patients who were treated with pronator teres tenotomy. The mean age of patients with pronator tenotomy was 4 years 3 months compared with 7 years 3 months for patients with rerouting. Follow-up averaged 94 months for tenotomy and 21 months for rerouting. Average gain in supination was 78 degrees for rerouting and 54 degrees for tenotomy. No patient lost active range of motion during follow-up. Although pronator teres tenotomy increased active supination of the forearm, greater active supination of the forearm was afforded patients treated with pronator teres rerouting.

Adolescent↗
PubMed1978

[Contribution of the biceps brachii and pronator teres muscles to the efforts of pronation or supination. I. Statistical work (author's transl)].

The electrical activity of the biceps brachii and pronator teres muscles is studied through the prono-supination of the forearm in some isometrical conditions (static work) with different loads and joint positions. If the pronator teres is always being active in pronation, this activity is a function of the load and of the wrist and elbow positions. The same phenomena can be observed for the biceps brachii but when in supination. From the curvilinear relationships between the integrated electrical activity and the load--observed on both muscles--some torque-angle relationships can be established for the biceps brachii which show that a bifunctional muscle seems to be characterized by a very and unique force-length relationship.

Arm↗
PubMed1978

[Contribution of the biceps brachii and pronator teres muscles to the efforts of pronation or supination. II. dynamic work (author's transl)].

The electrical activity of the biceps brachii and pronator teres muscles is studied through the prono-supination of the forearm in some anisometrical conditions (dynamic work) when the inertia of the mobile system and the elbow position are being varied. The subjects are required to perform pronation, supination and flexion movements, either isolated or combined. From the findings obtained when the integrated electrical activity (Q) is related to the mechanical work (W), one can conclude that a. the Q-W linear relationship seems to characterize the chief function of a muscle, b. the slope of the Q-W relationship depends on the elbow position, c. the pronator muscles do not inhibit in a selective manner the biceps supinating function. So a bifunctional muscle seems to act as a whole.

Biomechanical Phenomena↗
PubMed1992

Electromyography of pronators and supinators in great apes.

We obtained electromyographic recordings from the supinator, biceps brachii, pronator quadratus, and pronator teres muscles of a chimpanzee and a gorilla and from the supinator, pronator quadratus, and biceps brachii muscles of an orangutan as they stood and walked quadrupedally on horizontal and inclined surfaces, engaged in suspensory behavior, reached overhead, and manipulated a variety of foods and artifacts. In Pan troglodytes and Pan gorilla, as in Homo sapiens, the supinator muscle is the prime supinator, with the biceps brachii muscle serving to augment speed or force of supination. Primary of the pronator quadratus muscle over the pronator teres muscle during pronation is less clear in the African apes than in humans. Possibly, pongid radial curvature or forelimb elongation or both factors are related to the somewhat different patterns of activity that we observed in the pronator muscles of Pan versus those reported for Homo sapiens. In Pongo pygmaeus, as in P. troglodytes and P. gorilla, the pronator quadratus muscle acts as a pronator and the supinator muscle acts to supinate the hand at the radioulnar joints. The biceps brachii muscle is active at low levels as the orangutan supinates its hand with the elbow flexed.

Animals↗
PubMed1985

The flexor function of the m. pronator teres in man: a quantitative electromyographic study.

The muscle pronator teres was studied by surface electromyography during elbow flexion in a horizontal plane. The forearm was in semi-pronation and movement was performed at various velocities. A quantitative comparison was made between pronator teres activity and two main elbow flexors, biceps brachii and brachioradialis. The mean timing of the onset of activity was constant: biceps brachii was activated first followed by pronator teres and brachioradialis, and the lower the velocity of flexion, the earlier was the onset of biceps brachii activity. There was a linear relationship between the integrated EMG from each muscle and the work done. However, this relationship was less exact for pronator teres and brachioradialis at low values of work, a finding which opens questions about the generality of this relationship and about the "muscle equivalent" concept. Pronator teres appears to participate in elbow flexion besides its role in pronation. Despite similar anatomical peculiarities, pronator teres does not behave in the same way as anconaeus or popliteus and, above all, it is not the sole muscle active in slow movement. Thus, all the stocky muscles lying close to an articulation do not behave in the same way.

Adult↗
PubMed1985

The pronation capacity of the foot--its consequences for axial deformity after tibial shaft fractures.

In spite of the fact that discomfort from the subtalar area is common after varus-deformed tibial shaft fractures no plausible mechanism is to be found in the literature. A mechanical analysis of the problems shows that a varus deformity is compensated as pronation of the foot. A limited pronation capacity could thus be the cause of the pain. Pronation capacity was accurately measured in ten osteoligamentous preparations. The average pronation capacity was found to be 9.5 degrees +/- 7.0 degrees. There was a marked interindividual variation. In two of the specimens the pronation capacity was less than 1 degree. Capacity decreased by 0.21 degree for every degree increase in plantar flexion of the ankle joint. Thus, a small pronation capacity may be the mechanical basis for ankle complaints after varus-deformed tibial shaft fractures. An anterior angulation, compensated as planar flexion, further decreases the pronation capacity and adds to the risk associated with varus deformities.

Aged↗
PubMed1985

Brief or new: two pronation splints.

For two years we have made pronation splints to assist quadriplegic patients who lack adequate forearm pronation but who have enough upper extremity strength to feed themselves and perform other self-care or functional activities. We have found the splints to be an appropriate alternative to the MAS. The first pronation splint fits underneath the arm, is simple in design and fabrication, and is hidden. However, occasionally the lever of the splint hangs up in the shirt, catches on the post of the wheelchair, or slips out from underneath the arm when the patient reaches away from the body. To eliminate these problems, we designed a second splint. But, this splint requires more time to make and adjust, has two parts to put on instead of one, and is more noticeable because it is worn on top of the arm rather than underneath it. When a patient uses either splint, the degree of pronation may be adjusted according to the activity by slightly rotating the splint either way when strapping it on. For example, full pronation may be required for feeding, but only half the range is necessary to operate the keyboard of a computer or typewriter. Once the Velcro straps are applied, the splints do not slip. The splints are not interchangeable from left to right and assistance is always needed to put them on. For patients with "weak" or "absent" wrist extensors, a wrist support and cuff splint may be used along with the pronation splint or a universal cuff, if wrist extension is adequate. The pronation splints are appropriate for those patients whose forearms supinate when they reach their hand to or near their mouth.

Equipment Design↗
PubMed1987

Atypical electromyographic findings in pronator teres syndrome.

The electrodiagnostic differentiation between pronator teres syndrome and entrapment of the median nerve at the ligament of Struthers is generally thought to be aided by the absence of electromyographic (EMG) findings in the pronator teres muscle in pronator syndrome. This report describes a patient with surgically documented pronator teres syndrome who had EMG changes in the m. pronator teres, which was apparently innervated as or after the median nerve passed through. It is concluded that EMG abnormalities in the m. pronator teres should not alone be used to distinguish pronator teres syndrome from entrapment of the median nerve at the ligament of Struthers.

Diagnosis, Differential↗
PubMed1991

The free moment of ground reaction in distance running and its changes with pronation.

Many running injuries are successfully treated with footwear modifications designed to reduce pronation, but the underlying mechanism of treatment is not well understood. Previous attempts to correlate reduction in pronation with changes in ground reaction parameters have been unsuccessful. In this study, the free moment of ground reaction (Mz') was measured for 10 rearfoot strikers running at 4.5 m s-1 in each of three different pairs of running shoes designed to vary the extent of pronation during ground contact. Mz' patterns were highly variable between feet, but were repeatable within a given foot/footwear combination. Mz' was greatest in magnitude during the first half of support, when it acted in a direction resisting foot abduction, a component of pronation. It was opposite in sign and smaller in magnitude during the last 30% of support. The peak magnitude and the net angular impulse of Mz' were both increased significantly with increases in pronation. A net ground reaction moment was also calculated about a vertical axis fixed in the shoe, and was used in a first approximation model of the shoe/ground interface to predict when the foot is most likely to ab/adduct during running. In conclusion, this study characterized the Mz' pattern for a well-defined group of runners, and found that Mz' is sensitive to relatively large within-subject changes in pronation.

Adult↗
PubMed1991

[Three-dimensional CT study of the carpus under pronation-supination constraints].

By studying 3D imaging of the wrist under pronation-supination strain, we found that the simple comparison of a series of two corresponding cuts may provide a great deal of useful information on how the carpus transmits the longitudinal torque from the forearm to the hand. A special wooden trestle was made to fix the subject in the CT scanner in a permanent effort of pronation or supination. In the first group of scans, this effort was said to be "free" because the hand was simply maintained in a fixed window without any muscular contraction, except pronation or supination muscles. In the second group of scans, this effort was said to be "constrained" because the hand gripped a fixed bar with contraction of the flexor muscles. The thickness of the cuts was 1.2 millimeters and they were separated by 1.5 millimeters. Four levels were specially studied: the lower radio-ulnar joint (LRUJ), the proximal row of the carpus, the distal one and the metacarpal bases. Many elementary movements occur in the carpus in constrained supination: the triquetrum "supinates" (7 degrees), the scaphoid flattens and "pronates" (2 degrees) around the capitum the ridges of the carpal anterior concavity approximate (3 mm). In constrained pronation, the anterior concavity of the carpus flattens emphasizing the role of the anterior retinaculum. The LRUJ is very unstable: in free pronation, the ulnar head moves dorsally, firmly pressing the posterior part of the sigmoid notch, responsible for fracture of a postero-medial fragment in Colles fracture. The quadratus pronatus is a very important muscle to coapt this joint. We propose the "screwing (or unscrewing) test" in the diagnosis of arthrosis or instability of the LRUJ. We define the notion of "rotational shift" to appreciate the quality of the pronation/supination torque transmission. In constrained pronation/supination, this rotational shift is 5 degrees in the radio-carpal joint. This is very important to appreciate the quality of the wrist prosthesis. In free pronation/supination, the rotational shift is 45 degrees between radius and metacarpal bases. In constrained pronation/supination, it becomes 10 degrees. The wrist ligaments are unable to resist the wrist rotational shift and favor the torque transmission. The tendinous caging of the wrist is the main factor for maintaining rigidity of the carpus and transmitting the torque as muscles are contracted. The wrist can be compared with a fluid drive clutch, whose pedal is muscular contraction.

Biomechanical Phenomena↗
PubMed1991

[Complex movement analysis: dynamic study of the effect of a tape bandage on pronation in high-jumping with three-dimensional movement analysis and electromyography].

Overuse syndromes in the lower extremity are a frequent problem in athletics, especially in jumping events. Athletes notice a comfortable support by using ankle taping without restriction of their performance. Up to now no objective data is available about efficiency of taping against overpronation which is frequent in high jumping. In high jumping without boots little difference of pronation between taped and untaped take off leg was found. In contrast in jumping with spikes boots a marked pronation during take off was found, which was reduced by ankle taping with a reduction of maximum medial malleolar medialisation by 77%, reduction of pronation time by 33% and time of maximum pronation by 8.2% in the take off leg. Surface electromyography showed an increased activity of M. peroneus longus by 30.7% as a plantarflector and pronator muscle with ankle taping. Activity of other jump supporting muscles of the lower extremity was little influenced.

Adolescent↗
PubMed1991

The pronator syndrome. An evaluation of dynamic maneuvers for improving electrodiagnostic sensitivity.

The role of three test maneuvers (elbow flexion, forearm pronation and finger flexion against resistance) in improving sensitivity of conventional nerve conduction studies used in cases of suspected pronator teres syndrome were evaluated in 11 healthy control subjects and 10 patients with the clinical diagnosis of pronator teres syndrome. Stimulation of the median nerve was performed above and below the elbow before exercise and immediately after the test maneuvers; the resultant median motor and sensory responses were recorded. Before and after exercise, median motor and sensory responses (e.g., amplitude, latency, velocity) did not differ significantly between the two groups; only one patient with suspected pronator teres syndrome developed sensory amplitude changes after exercise. We concluded that these test maneuvers did not significantly improve the sensitivity of conventional nerve conduction studies in the diagnosis of pronator teres syndrome.

Adult↗
PubMedDate not supplied

Clinical and neurophysiologic characteristics of the pronator syndrome.

Nine patients were clinically diagnosed as having a pronator syndrome, i.e., high median nerve compression. The main symptom was pain at the proximal volar aspect of the forearm increasing for several hours after exercise. All patients showed local tenderness over the median nerve 4-5 cm distal to the elbow and pain on active forearm pronation against resistance. Two patients had been previously operated upon for carpal tunnel syndrome. Preoperative routine neurographic-electromyographic studies were normal. In the differential diagnosis, the exclusion of carpal tunnel syndrome and anterior interosseous nerve entrapment is most important. On active isometric forearm pronation, interference with median nerve motor conduction occurred in three patients preoperation. This phenomenon had disappeared following median nerve decompression at the level of the pronator muscle. Fibrous bands from the pronator muscle, encircling the nerve, seemed to be an etiological factor. Eight of nine patients were either improved or recovered completely by surgical treatment.

Adult↗
PubMed1992

Surgery for cerebral palsy: Part 1. Classification and operative procedures for pronation deformity.

32 patients with cerebral palsy underwent operations for pronation deformity. The deformity is classified into four groups. Patients in group 1 are capable of supination beyond neutral. No surgery is necessary. Those in group 2 are able to supinate to the neutral position. A pronator quadratus release is advised and may be combined with a flexor aponeurotic release. In group 3, patients have no active supination. However a full range of passive supination is readily achieved. A pronator teres transfer is advised. Patients in group 4 have no active supination. Full passive supination may be present, but is tight. A flexor aponeurotic release and a pronator quadratus release may unmask active supinator activity. An active transfer for supination is possible as a secondary procedure.

Adolescent↗
PubMed1990

The pronator compression test revisited. A forgotten physical sign.

Pronator compression testing is a valuable clinical feature of median nerve entrapment diagnosis. Of 10 patients with this disorder, all developed paresthesias preoperatively in the hand after 30 seconds or less of manual compression of the median nerve at or near the pronator muscle. Eight patients had a positive Tinel's sign at the impingement site, but only one patient had a positive electromyographic result. More than 50% of the patients had undergone previous carpal tunnel release or were diagnosed at presentation with double crush syndrome. All patients had a good or excellent result from surgical decompression of the median nerve in the forearm, except for one workers' compensation case who had excellent postoperative strength testing but multiple residual complaints. Pronator compression testing is a helpful and dependable physical sign in the diagnosis of pronator syndrome.

Carpal Tunnel Syndrome↗
PubMed1990

Median nerve entrapment. Pronator teres syndrome. Surgical anatomy and correlation with symptom patterns.

The surgical anatomy of interest in the pronator teres syndrome was studied to shed light on the ramifying pattern of the median nerve, the number of its muscular branches and their branching levels and to pinpoint the location of the fibrous bands which may cause median nerve entrapment. The fibrous arch of the pronator teres muscle (pronator arch) was found to lie 3 cm to 7.5 cm below Hueter's line, that of the flexor digitorum superficialis muscle (superficialis arch), which is distal to the pronator arch, was found to lie 6.5 cm below Hueter's line in its most proximal position. Symptom patterns in terms of muscle weakness caused by median nerve entrapment at different levels were also evaluated.

Arm↗
PubMedDate not supplied

Variations of the pronator teres muscle: predispositional role to median nerve entrapment.

The variability of the human pronator teres muscle is studied in 60 upper limbs. The humeral head was present in all cases and was double in 3 cases (5.0%). The ulnar head was present in 47 cases (78.3%). The ulnar head was muscular in 11 cases, tendinous in 6 cases, and mixed in 30 cases. The collateral branches of the median nerve destined to the pronator teres muscle were found to be arranged in three main patterns: arising directly from the median nerve, arising from the superficial flexor antebrachial muscles nerve, and mixed type. Special reference is made to the influence of variations in the pronator teres muscle on the compression or the entrapment of the median nerve (pronator syndrome). The proposed determinant variations are: short and tendinous ulnar head, ulnar head joined to the arch of the flexor digitorum superficialis muscle, ulnar head with triple origin slips, and humeral head perforated by the median nerve.

Cadaver↗