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At least 19 recordsLinked to original sources
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↗
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↗
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↗
PubMed1979

[The pronator teres syndrome. Clinical aspects, pathogenesis and therapy of a non-traumatic median nerve compression syndrome in the space of the elbow joint].

The proximal compression neuropathy of the median nerve is described by 11 personal cases and a review of literature. The most reliable diagnostic sign is "pronation-pain", discomfort in the forearm localised under the pronator teres, produced by passive supination of the wrist, by active pronation from this position against resistance, okr by local pressure. A nearly constant finding is weakness of grip and paraesthesia or hypaesthesia of the fingers, not always following the normal median nerve distribution. Three different anatomic points of possible compression are described: 1. The supracondylar process of the humerus, or Struthers' ligament, a rare compression mechanism. 2. The passing of the nerve through the two variable heads of the pronator teres muscle. 3. The sharp edged superficialis bridge. Apart from compression of the entire median nerve single branches of the median nerve can be entrapped seperately (the anterior interosseus nerve, the Martin-Gruber-anastomosis to the ulnar nerve) Conservative treatment with immobilisation and local electric interference current application may be satisfactory. If clinical improvement is insufficient, surgical decompression is indicated.

Adolescent↗
PubMed1992

Mathematical modelling of the effect of sole elasticity distribution on pronation.

A coronal plane model of a distributed elastic sole has been proposed and analyzed with respect to the effects of different medial-lateral elasticity distribution on pronation under quasi-static conditions. The distributed model consists of an array of linear vertical line springs. Under minimum energy assumption, the behavior of the top surface of the interface under resultant force and moment loading was shown to be equivalent to that of a rigid-body mechanism under the same loading. The model was then combined with a rigid-link model of the lower limb. Expressions that describe the relationship of the interface aggregate parameters with pronation and the center of pressure were obtained. These expressions were confirmed by an experiment in which the elastic distribution in the interface was systematically varied and the pronation angle and the center of pressure measured. The model has the potential of being a useful analytical tool in the design of elastic soles in running shoes.

Ankle Joint↗
PubMed1992

The medial heel skive technique. Improving pronation control in foot orthoses.

A new method of foot orthosis modification that enhances the pronation controlling ability of foot orthoses is presented. The medial heel skive technique involves selectively removing small amounts of the medial portion of the plantar heel of the positive cast of the foot to create a unique varus wedging effect within the heel cup of the foot orthosis. The resulting increase in supination moment across the subtalar joint axis of the foot clinically produces significantly improved pronation control on pediatric flexible flat feet, posterior tibial dysfunction, and other types of excessively pronated feet.

Biomechanical Phenomena↗
PubMed1976

Pronator syndrome: clinical and electrophysiological features in seven cases.

The clinical and electrophysiological picture of seven patients with the pronator syndrome is contrasted with other causes of median nerve neuropathy. In general, these patients have tenderness over the pronator teres and weakness of flexor pollicis longus as well as abductor pollicis brevis. Conduction velocity of the median nerve in the proximal forearm is usually slow but the distal latency and sensory nerve action potential at the wrist are normal. Injection of corticosteroids into the pronator teres has produced relief of symptoms in a majority of patients.

Adrenal Cortex Hormones↗
PubMed1990

Transfer of the pronator teres tendon to the tendons of the flexor digitorum profundus in tetraplegia.

In eleven patients who had traumatic tetraplegia, the pronator teres tendon was transferred to the flexor digitorum profundus tendons to restore active flexion of the fingers. At the same time, in ten of these patients the tendon of the brachioradialis was transferred to the tendon of the flexor pollicis longus, and in the eleventh patient the brachioradialis tendon was transferred to the tendon of the flexor digitorum superficialis of the small finger, to restore pinch. The average time between injury and operation was thirty-four months. The average length of follow-up after operation was thirty-four months. Ten patients gained functional active flexion of the fingers, and they reported improved performance of activities of daily living. When the wrist was in 30 degrees of extension, the average active grasp strength was twenty-one millimeters of mercury and the average key-pinch strength was 2.2 kilograms. The average active flexion of the fingers from the resting position, measured from the tip of the finger to the distal palmar crease, was 1.5 centimeters. Only one patient did not gain active flexion of the fingers. Of the entire group, this patient had the least function of the hand on preoperative evaluation; retrospectively, he seemed to be a poor candidate for operation, since the strength of the pronator teres muscle and the sensibility of the hand were insufficient for useful function. We concluded that, in selected tetraplegic patients, transfer of the pronator teres tendon to the flexor digitorum profundus tendons provides useful active flexion of the fingers.

Adult↗
PubMedDate not supplied

Neuroleptanalgesia for awake pronation of surgical patients.

Pronation of anesthetized patients may result in complications. Neuromuscular block increases the risk. To minimize the risk, the authors devised a technic of "awake pronation," evaluating its feasibility, in 11 consecutive patients in a 1-year period for 12 operations; all attempts were successful and without complicatons. Neuroleptanalgesia is achieved with droperidol and fentanyl, topical anesthesia of the upper airway is induced with lidocaine, awake intubation is performed orotracheally under direct vision, and pronation is accomplished with patient cooperation.

Administration, Topical↗
PubMed1991

Modification of high-heeled shoes to decrease pronation during gait.

One of the reasons that high heels may contribute to the formation of halux valgus is that the wearers pronate during propulsion. This pilot study was performed to determine whether relocation of the heel under the counter of a fashion high-heeled pump could change the degree of pronation of the foot during the gait cycle. The authors report that more foot stability was experienced by the subjects when the center of the heel was offset between 2 and 4 mm medial to the center of the heel counter. This study is designed to promote further research into whether the shoe industry should change the design parameters of high-heeled fashion shoes in order to improve foot function.

Adult↗