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Biomedical subjects

D J Antonelli

Publications and source records attributed to D J Antonelli.

7 recordsLinked to original sources
PubMed1986

Electromyography and motion analysis of the upper extremity in sports.

This article reviews the results of studies using electromyographic recordings to determine muscle function during athletic activities. Electromyographic recordings were synchronized with high-speed film to provide information on shoulder muscle firing patterns during baseball pitching, swimming, tennis, and golf. The information obtained about the contributions of specific muscles during these activities may be useful in developing effective injury prevention and rehabilitation strategies.

Baseball↗
PubMedDate not supplied

Rotator cuff function during a golf swing.

A study of bilateral shoulder muscle activity during the golf swing was undertaken using electromyography and high-speed photography. Understanding of the muscle firing patterns could lead to injury prevention and development of appropriate training and conditioning regimens. The swings of seven adult male right-handed professional golfers without shoulder problems were examined. Indwelling electrodes were inserted into the supraspinatus, subscapularis, infraspinatus, latissimus dorsi, pectoralis major, anterior deltoid, middle deltoid, and posterior deltoid on the right side. Each subject was allowed to warm up until he felt comfortable. Films of each subject were taken at 450 frames per second. The swing was broken into four segments to which electromyographic signals were synchronized electronically. The EMG tracings were subjected to analog-to-digital conversion and a relative measure of quantity obtained. All tests were repeated on the left side for each subject. Results indicate that all portions of the deltoid were inactive on the right side throughout the swing. The deltoid was likewise inactive on the left except for a brief spurt from the anterior portion during the milliseconds immediately preceding ball contact. Of the rotator cuff muscles, on the left the supraspinatus fired at a low level throughout the swing, as did the infraspinatus. The latter had a slightly larger burst of activity immediately after ball contact. The subscapularis was more active than any other muscle throughout the swing. The cuff muscles on the right side showed as much activity overall as those on the left. In addition, the latissimus dorsi and pectoralis major seemed to provide power bilaterally, with marked activity during the acceleration phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

An electromyographic analysis of the elbow in pitching.

Elbow injuries are common in baseball pitchers. Curve balls are thought to increase this risk, particularly if the athlete begins throwing this pitch at an early age. The purpose of this paper is to identify forearm muscle firing patterns during the pitching cycle in an effort to understand this etiology. Dynamic EMG was performed on eight collegiate pitchers to evaluate extensor digitorum communis, brachioradialis, flexor carpi radialis, flexor digitorum superficialis, extensor carpi radialis longus, extensor carpi radialis brevis, pronator teres, and supinator. Each subject threw a fast ball and curve ball, which were filmed at 450 frames per second and synchronized with the EMG. These signals were converted from analog to digital records. Results showed low to moderate activity in all muscles during all phases of the pitch. The function is probably positioning to accept the transfer of energy from the larger trunk and girdle structures. The most notable difference between the fast ball and curve ball is a slight increase in the extensor carpi radialis longus and extensor carpi radialis brevis activity during late cocking, acceleration, and follow-through of the curve ball as compared to the fast ball. This difference, however, is not significant. In addition, there was no significant difference between the fast ball and the curve ball in the flexor-pronator group in any phase. We cannot substantiate that medial elbow problems are a result of an increase in the use of flexor muscles during the curve ball pitch.

Adult↗
PubMedDate not supplied

An electromyographic analysis of shoulder function in tennis players.

Shoulder injuries in tennis players are common because of the repetitive, high-magnitude forces generated around the shoulder during the various tennis strokes. An understanding of the complex sequences of muscle activity in this area may help reduce injury, enhance performance, and assist the rapid rehabilitation of the injured athlete. The supraspinatus, infraspinatus, subscapularis, middle deltoid, pectoralis major, latissimus dorsi, biceps brachii, and serratus anterior muscles were studied in six uninjured male Division II collegiate tennis players using dynamic electromyography (EMG) and synchronized high-speed photography. Each subject performed the tennis serve and the forehand and backhand groundstrokes, and each stroke was divided into stages. The tennis serve contains four stages. Three stages characterize the forehand and backhand groundstrokes. Our results indicate that the subscapularis, pectoralis major, and serratus anterior display the greatest activity during the serve and forehand. The middle deltoid, supraspinatus, and infraspinatus are most active in the acceleration and follow-through stages of the backhand. The biceps brachii increases its activity during cocking and follow-through in the serve with a similar pattern noted in the acceleration and follow-through stages of the forehand and backhand. The serratus anterior demonstrates intense activity in the serve and forehand, thus providing a stable platform for the humeral head and assisting in gleno-humeral-scapulothoracic synchrony. The tennis serve and forehand and backhand groundstrokes are accomplished by complex sequences of muscle activity that incorporate contributions from the lower extremities and trunk into smooth, coordinated patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗