Head Of Triceps Brachii Muscle Research Articles

An intramuscular lipoma in the medial head of triceps brachii muscle simulating nerve sheath tumour of ulnar nerve: a rare case report

Lipomas are the most frequent benign mesenchymal neoplasms of mature fat cells found commonly on the back and upper extremities usually occupying the subcutaneous plane. Intramuscular lipomas are rare and may mimic malignant lesions. Magnetic resonance imaging can not only identify and localise these tumours but also differentiate them from malignant liposarcomatous lesions. Here we present a case of intramuscular lipoma of the medial head of Triceps brachii in a 70 year old male clinically mimicking as nerve sheath tumour of the ulnar nerve.

A case of avulsion fracture of the long and lateral heads of triceps brachii muscle

A case of avulsion fracture of the long and lateral heads of triceps brachii muscle

Muscle MRI of the Upper Extremity in the Myotonic Dystrophy Type 1

Background: The purpose of this study was to explore the relation between muscle MRI findings and weakness of the upper extremity muscles in patients with myotonic dystrophy type 1 (DM1). Methods: Nineteen DM1 patients from 15 families were enrolled in this study. Muscle weakness was evaluated using the modified Medical Research Council scale. Subjects also underwent a genetic study and muscle MRI of the upper extremities. Results: In patients with DM1, the flexor digitorum profundus (FDP), flexor pollicis longus, flexor digitorum superficialis (FDS), extensor pollicis, abductor pollicis longus (APL), lateral head of triceps brachii and infraspinatus (INF) muscles were frequently and severely affected. Muscle strength was significantly correlated with the severity of muscle MRI findings in the FDP, short head of biceps brachii (SBB), and medial head of triceps brachii muscles. Disease duration was correlated significantly with MRI findings in the FDP, FDS, long head of biceps brachii, INF, APL, and SBB muscles. Unexpectedly, the degree of trinucleotide expansion of myotonin protein kinase was not correlated with muscle MRI findings. Conclusion: Muscle MRI of the upper extremity is useful to detect affected muscles in DM1 patients.

Muscle Fatigue in the Three Heads of the Triceps Brachii During a Controlled Forceful Hand Grip Task with Full Elbow Extension Using Surface Electromyography.

The objective of the present study was to investigate the time to fatigue and compare the fatiguing condition among the three heads of the triceps brachii muscle using surface electromyography during an isometric contraction of a controlled forceful hand grip task with full elbow extension. Eighteen healthy subjects concurrently performed a single 90 s isometric contraction of a controlled forceful hand grip task and full elbow extension. Surface electromyographic signals from the lateral, long and medial heads of the triceps brachii muscle were recorded during the task for each subject. The changes in muscle activity among the three heads of triceps brachii were measured by the root mean square values for every 5 s period throughout the total contraction period. The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle. Muscle fatigue in the long, lateral, and medial heads of the triceps brachii started at 40 s, 50 s, and 65 s during the prolonged contraction, respectively. The highest fatiguing rate was observed in the long head (slope = −2.863), followed by the medial head (slope = −2.412) and the lateral head (slope = −1.877) of the triceps brachii muscle. The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

Highest extent of lateral and medial heads of triceps brachii muscle

Abstract Introduction: Various studies have been done on triceps brachii muscle but the description of the highest extent of lateral and medial head of triceps brachii muscle remained unexplored that is why this study was undertaken to know the extent of their proximal attachments in relation to anatomical neck of humerus and capsule of shoulder joint. Materials and Methods: The shoulder region of 50 formalin fixed upper limbs were dissected to explore the capsule of shoulder joint to reach the highest extent of lateral & medial head of triceps brachii muscle where the nature of fibres, fleshy or tendinous was noted. Oblique and vertical distances of proximal attachment of lateral & medial head of triceps brachii muscle to the anatomical neck of humerous was measured with the help of a sliding caliper. Results: Medial head of triceps brachii muscle in all the cases was fleshy in origin while that of lateral head; fibres were fleshy and tendinous in 82% & 18% of cases, respectively. Fibres of lateral and medial head were blending with the capsule of shoulder joint in 28% & 6% of cases respectively. Maximum cases of lateral head were having their oblique and vertical distances between 21-40 mm (64% & 58% respectively) while those for medial head were >40 mm (68% & 74% respectively). Conclusion: Accurate knowledge of these anatomical patterns of triceps brachii muscle are of considerable clinical importance in the conduct of reparative open access and arthroscpic surgeries around the shoulder and the fracture management of the upper end of humerus.

Evaluation of repetitive isometric contractions on the heads of triceps brachii muscle during grip force exercise.

Normally, surface electromyography electrodes are used to evaluate the activity of superficial muscles during various kinds of voluntary contractions of muscle fiber. The objective of the present study was to investigate the effect of repetitive isometric contractions on the three heads of the triceps brachii muscle during handgrip force exercise. Myoelectric signals were recorded from the lateral, long and medial heads of the triceps brachii muscle in 13 healthy males during maximal isometric contractions for 10 s of concurrent handgrip force and elbow extension. The subjects were asked to perform their contraction task five times with 3 minutes interval between two successive contractions. Decreasing electromyographic activities were found for the lateral and long heads, and increasing for the medial head throughout the 5 different contractions. Electromyographic activities were found for the lateral head with mean=199.84, SD=7.65, CV=3.83%, the long head with mean=456.76, SD=18.10, CV=3.96%, and the medial head with mean=505.16, SD=8.47, CV=1.68%. Electromyographic activities among the three heads of triceps brachii were significantly different (F=3.82) at the alpha level of (p<0.05). These findings support that repetitive isometric contractions decrease the contractile activity in the lateral and long heads, and increases in the medial head of the triceps brachii muscle during handgrip force exercise with full elbow extension, and the electromyographic activity changes are observed to be more significant at the long head as compared to the lateral and medial heads.

The medial head of the triceps brachii. Anatomy and blood supply of a new muscular free flap: the medial triceps free flap

The anatomical features of the posterior compartment of the arm seem to provide the basis to raise one of the smallest free muscular flaps, with minimal donor site morbidity: the medial triceps free flap. The anatomic study was carried out on 27 fresh cadaver arms: 7 prepared for corrosion cast, 15 for simple dissection and 5 for dissection after latex injection. Morphological data of the muscle, as well as pedicle constancy and size, were recorded. The mean size of the medial head was 10.7×2.5×3.3cm; the mean weight was 30.1g. We found a constant and unique pedicle supplying the whole medial head of triceps muscle, composed by the middle collateral artery (MCA), two veins and a nerve. The mean length of MCA was 2.9cm and the "extended" pedicle, including the deep brachial artery (DBA), was 8-12cm long. At their origin, the mean caliber of MCA was 1.5mm and the mean caliber of DBA 2.4mm. Our findings confirmed the reliability of the MC vessels and their anatomical relationships with the medial head of triceps brachii muscle, which could be harvested as a free flap or as a pedicled flap based on anterograde or retrograde flow. This technique should be safe, yielding mild donor site morbidity, and suitable in regional reconstruction or distant reanimations.

Axillopectoral muscle (Langer's muscle)

In a routine dissection of the axillary fossa, a muscle originating from the coracoid process of the scapula and extending to the long head of triceps brachii muscle was observed. The mentioned muscle was adhering to both the triceps brachii muscle and the tendinous part of the latissimus dorsi muscle. This anatomical variation is referred to as axillary arch (Langer's muscle or axillopectoral muscle). The muscle mass was measured 9.6 cm in length and 1.4 cm in width. The accessory muscle can be a reason of an axillary mass and can exert pressure on the neighboring neurovascular bundle or lymph routes; thus, exposing a wide range of symptoms. Therefore, variations of this area should be kept in mind in surgical interventions.

Is the spring quality of muscle plastic?

During locomotion, major muscle groups are often activated cyclically. This alternate stretch-shorten pattern of activity could enable muscle to function as a spring, storing and recovering elastic recoil potential energy. Because the ability to store and recover elastic recoil energy could profoundly affect the energetics of locomotion, one might expect this to be an adaptable feature of skeletal muscle. This study tests the hypothesis that chronic eccentric (Ecc) training results in a change in the spring properties of skeletal muscle. Nine female Sprague-Dawley rats underwent chronic Ecc training for 8 wk on a motorized treadmill. The spring properties of muscle were characterized by both active and passive lengthening force productions. A single "spring constant (Deltaforce/Deltalength) from the passive length-tension curves was calculated for each muscle. Results from measurements on long heads of triceps brachii muscle indicate that the trained group produced significantly more passive lengthening force (P = 0.0001) as well as more active lengthening force (P = 0.0001) at all lengths of muscle stretch. In addition, the spring constants were significantly different between the Ecc (1.71 N/mm) and the control (1.31 N/mm) groups. A stiffer spring is capable of storing more energy per unit length stretched, which is of functional importance during locomotion.

Effects of exercise training on coronary transport capacity.

Coronary transport capacity was estimated in eight sedentary control and eight exercise-trained anesthetized dogs by determining the differences between base line and the highest coronary blood flow and permeability-surface area product (PS) obtained during maximal adenosine vasodilation with coronary perfusion pressure constant. The anterior descending branch of the left coronary artery was cannulated and pump-perfused under constant-pressure conditions (approximately equal to 100 Torr) while aortic, central venous, and coronary perfusion pressures, heart rate, electrocardiogram, and coronary flow were monitored. Myocardial extraction and PS of 51Cr-labeled ethylenediaminetetraacetic acid were determined with the single-injection indicator-diffusion method. The efficacy of the 16 +/- 1 wk exercise training program was shown by significant increases in the succinate dehydrogenase activities of the gastrocnemius, gluteus medialis, and long head of triceps brachii muscles. There were no differences between control and trained dogs for either resting coronary blood flow or PS. During maximal vasodilation with adenosine, the trained dogs had significantly lower perfusion pressures with constant flow and, with constant-pressure vasodilation, greater coronary blood flow and PS. It is concluded that exercise training in dogs induces an increased coronary transport capacity that includes increases in coronary blood flow capacity (26% of control) and capillary diffusion capacity (82% of control).

Observations on normal skeletal muscle of mature dogs: a cytochemical, histochemical, and morphometric study.

Cytochemical, histochemical, and morphometric features of skeletal muscle were evaluated in 140 specimens from five appendicular muscles of 28 dogs which were free of neuromuscular disease. Dogs ranged from six months to 15 years of age. Evidence of degeneration and regeneration, cell reactions and architectural change was found but with an incidence of less than 1% of the total myofiber population in any muscle. The number of fibers with internal nuclei never exceeded 1%. The only changes that appeared to be age-related were fiber size variation associated with the presence of small angular type IIA fibers in muscles of dogs seven years of age and older. Percentages of type I, type IIA, and type IIC fibers remained relatively constant in the various muscles in the age range examined. Type I fibers predominated in medial head of triceps brachii and superficial digital flexor muscles, whereas type IIA fibers were more numerous in biceps femoris and long head of triceps brachii muscles. An approximately equal ratio was found in gastrocranius muscles. In any given muscle, type IIC fibers represented less than 2% of the fibers. Statistically significant differences were found in values for fiber size between groups of dogs weighing more than (mean diameter range = 40 to 50 microns) and less than (mean diameter range = 30 to 40 microns) 15 kilograms.

Relationship between muscle force and muscle area showing glycogen loss during locomotion

This experiment was designed to study the relationship between the cross-sectional area of rat skeletal muscle showing glycogen loss and the muscle forces exerted during exercise. Muscular force exerted by the extensors of the elbows and ankle was increased by 24% by loading rats with 24% of their body mass while running them on a treadmill at 30 m.min-1. VO2 increased by 24% and stride frequency was unchanged when the rats ran with loads. Cross-sectional areas of the elbow and ankle extensor muscles showing glycogen loss were compared from rats running with and without the load. We found a nearly direct proportionality between the changes in force and the changes in muscle area showing glycogen loss, i.e. when the force of the extensors was increased by 24%, the cross-sectional area of the elbow extensors showing glycogen loss increased by 28%, and that of the ankle extensor group increased by 24%. The more peripheral muscles in each group accounted for a greater proportion of the increase in cross-sectional area of the group showing glycogen loss (i.e. lateral and long heads of triceps brachii muscle accounted for 91% of the increase in the elbow extensor group, and gastrocnemius muscle accounted for 84% of the increase in the ankle extensor group). Most of the increases in muscle area showing glycogen loss occurred in fast-twitch-glycolytic fibres (84% in the elbow and 88% in the ankle). The data suggest that increasing muscle force requirements by 24% by loading resulted in proportional increases in cross-sectional area of muscles recruited to produce the force, i.e. that spatial recruitment primarily accounted for the elevation in force. The relatively greater increases in cross-sectional area showing glycogen loss of peripheral muscles within a group indicate the importance of studying whole groups of muscles when considering muscular recruitment patterns during exercise.

Experimental investigation of glucocorticoid-induced myopathy in the dog

The susceptibility of type I and type II fibers in forelimb and hind limb muscles to glucocorticoid-induced morphometric, histochemical, and ultrastructural changes was investigated in adult dogs treated 3 to 28 days with prednisolone (4 mg/kg/day). Mild morphologic alterations that included focal fiber necrosis, phagocytosis and subsarcolemmal masses occurred after 1 week of glucocorticoid administration. Type II fibers became angular and atrophic after 2 weeks of treatment. Glucocorticoid administration over a 28-day period resulted in a significant ( P < 0.05) reduction in both mean fiber diameters and atrophy factors in vastus lateralis, biceps femoris, anterior tibialis, and the long head of triceps brachii muscles. Ultrastructural alterations in biceps femoris muscle samples included a sequential increase in number and size of intermyofibrillar vacuoles, a small increase in sarcoplasmic glycogen deposition, a dilatation of the sarcotubular system, and an increased subsarcolemmal and intermyofibrillar mitochondrial aggregation. These results are very similar to those reported in glucocorticoid-induced atrophy in other species, including man, and in hyperadrenocorticism in the dog.

Ulnar nerve contribution in the innervation of the triceps brachii muscle ulnar nerve to the triceps brachii

The ulnar nerve is considered the thickest terminal branch of the medial cord in the brachial plexus and most authors does not mention the possibility of this nerve emitting branches to the arm. However, some studies reported that the ulnar nerve could supply the medial head of triceps brachii muscle. The main objective in this study was identifying the presence of ulnar nerve branches in triceps brachii muscle. Sixty upper limbs of adult Brazilian corpses of both sexes were used. The estimated age was between 25 and 80 years old. Every studied piece had the nerves and their branches quantified and measured with a manual mechanic caliper. The branches were photographed and had the data registered in individual files. Were found ulnar nerve branches for all the heads of triceps brachii muscle: 1 branch (9,1%) to lateral head, 2 branches (18,1%) to long head and 8 branches (72,7%) to medial head. Thus, we can conclude that the contribution of ulnar nerve to triceps brachii muscle constitutes an important anatomical variation.Key words: Ulnar nerve; Triceps brachii muscle; Innervation.