scholarly journals Anatomical Description of the Forelimb Muscles of the Brown-Throated Sloth (Bradypus variegatus)

2018 ◽  
Vol 46 (1) ◽  
pp. 10
Author(s):  
João Augusto Rodrigues Alves Diniz ◽  
Bruna Miniz Rodrigues Falcão ◽  
Ediane Freitas Rocha ◽  
Joyce Galvão De Souza ◽  
Artur Da Nobrega Carreiro ◽  
...  
Keyword(s):  
Forest Canopy ◽  
Biceps Brachii ◽  
Extensor Digitorum ◽  
Flexor Digitorum Profundus ◽  
Pronator Quadratus ◽  
Flexor Muscles ◽  
The Subject ◽  
Forelimb Muscles ◽  
Bradypus Variegatus ◽  
Flexor Digitorum

Background: Brown-throated sloths are mammals of the order Xenarthra, suborder Pilosa, family Bradypodidae. These folivorous and arboreal animals, which possess a peculiar type of arboreal quadrupedalism, move through the forest canopy by means of suspensory locomotion. On the ground, their extremely slow movements make them easy targets for road accidents, often leading to serious injury or even death. This paper describes the forelimb muscles of the brown-throated sloth (Bradypus variegatus), updating the literature on the subject to help veterinarians in clinical and surgical interventions on this species, and to provide data for comparative animal anatomy.Materials, Methods & Results: Five brown-throated sloths (Bradypus variegatus Schinz, 1825), two adults and three babies were dissected. The animals were donated by the Arruda Câmara Zoo and Botanical Park in João Pessoa, state of Paraíba, Brazil, where they were thawed and fixed in 10% formalin. The sloths’ forelimbs were dissected by lifting and folding over a skin flap to expose, identify and describe the underlying musculature. The dissection revealed the following muscles: supraspinatus, infraspinatus, deltoideus, teres major, subscapularis, coracobrachialis, brachialis, biceps brachii, triceps brachii, anconeus epitrochlearis, dorsoepitrochlearis, brachioradialis, supinator, pronator teres, pronator quadratus, extensor carpi radialis, extensor carpi ulnaris, extensor carpi obliquus, flexor carpi radialis, flexor carpi ulnaris, extensor digitorum communis, extensor digitorum lateralis, palmaris longus, flexor digitorum superficialis, flexor digitorum profundus, extensor indicis longus second finger, extensor indicis brevis second finger, extensor digitorum third finger, abductor digitorum second finger, abductor digitorum third finger, palmaris brevis, and interosseous muscles. Characteristics found in this species revealed differences in the muscular development of the upper forelimb, whose muscles are less developed than those of the lower forelimb, which are visibly more developed with greater muscle density. An interesting feature of this musculature is the presence of three flexor tendons, short and thick, originating from the flexor muscles, which give the hand of the brown-throated sloth a hook-like aspect.Discussion: Our observations indicate that some of the muscles are very similar to those of other animals of this order and also of domestic mammals. However, the most relevant characteristics resemble those of arboreal animals and humans, since the forearm and hand pronation and supination muscles are essential for their arboreal habits. Therefore, all the pronator and supinator muscles of the brown-throated sloth are well developed. Due to the functional adaptations of the species of the family Bradypodidae, the shoulder muscles, especially the deltoideus, are more developed, providing greater support to the shoulder joint, and their origin and insertion assist in faster and easier movements, albeit exerting less force. The group of flexor muscles in this species gives the forearm stronger and more concentrated action than the extensor muscles. This study enabled us not only to produce a more precise description of the muscles of the forelimb of this species but also to update the literature, since there are few relevant studies on the subject and the terms in the literature are outdated and no longer in use. Keywords: sloth, Bradypodidae, morph

scholarly journals Bilateral Variation of Forearm Flexor Muscles - A Case Report and Clinical Significance

2012 ◽  
Vol 01 (01) ◽  
pp. 040-043
Author(s):  
D. Malar ◽  
Keyword(s):  
Middle Finger ◽  
Flexor Digitorum Profundus ◽  
Flexor Digitorum Superficialis ◽  
Flexor Carpi Ulnaris ◽  
Close Proximity ◽  
Flexor Muscles ◽  
Male Cadaver ◽  
Forearm Flexor Muscles ◽  
Flexor Digitorum ◽  
Forearm Flexor

AbstractDuring routine dissection, bilateral multiple variations of forearm flexor muscles were observed in a male cadaver. The variations were a) an additional belly arising from the coronoid process of ulna, distal to the origin of ulnar head of flexor digitorum superficialis, passing deep to flexor digitorum superficialis and joining the tendon of flexor digitorum profundus to the middle finger; b) an additional belly arising from the distal part of flexor carpi ulnaris and passing superficial to ulnar nerve and ulnar vessels in the Guyon's canal and c) the origin of second lumbricals from the profundus tendon in the carpal tunnel. An aberrant muscle may stimulate a ganglion or a soft tissue tumor or if in close proximity to a nerve, it may cause pressure neuritis. Identification of these variations is important in defining the anatomical features for clinical diagnosis and surgical procedures.

Neurotization as an alternative for restoring finger and wrist extension

2001 ◽  
Vol 94 (5) ◽  
pp. 795-798 ◽  
Author(s):  
Mehmet Erkan Üstün ◽  
Tunç Cevat Öğün ◽  
Mustafa Büyükmumcu
Keyword(s):  
Median Nerve ◽  
Motor Nerve ◽  
Flexor Digitorum Profundus ◽  
Posterior Interosseous Nerve ◽  
Flexor Pollicis Longus ◽  
Pronator Quadratus ◽  
Content Type ◽  
Pronator Teres ◽  
Flexor Digitorum ◽  
Fine Print

Object. In cases of irreparable injuries to the radial nerve or in cases in which nerves are repaired with little anticipation of restoration of function, tendon transfers are widely used. In this study, the authors searched for a more natural alternative for selectively restoring function, with the aid of a motor nerve transfer. Methods. Ten arms from five cadavers were used in the study. The posterior interosseous nerve and the median nerve together with their motor branches were exposed in the proximal forearm. The possibility of posterior interosseous nerve neurotization via the median nerve through its motor branches leading to the pronator teres, flexor pollicis longus, flexor digitorum profundus, and pronator quadratus muscles was investigated. The lengths of the nerves from points of divergence and their widths were measured using calipers, and the means with standard deviations of all nerves were calculated. Motor branches to the pronator teres, flexor pollicis longus, and pronator quadratus muscles were found to be suitable for neurotization of the posterior interosseous nerve at different levels and in various combinations. The motor nerve extending to the flexor digitorum profundus muscle was too short to use for transfer. Conclusions. These results offer a suitable alternative to tendon transfer for restoring finger and wrist extension in cases of irreversible radial palsy. The second step would be clinical verification in appropriate cases.

Anterior Interosseous Neuropathy in Instrumental Musicians

2006 ◽  
Vol 21 (3) ◽  
pp. 137-141
Author(s):  
Richard J Lederman
Keyword(s):  
Index Finger ◽  
Age At Onset ◽  
Flexor Digitorum Profundus ◽  
Left Index Finger ◽  
Pronator Quadratus ◽  
Motor Branch ◽  
Neuralgic Amyotrophy ◽  
Electrodiagnostic Testing ◽  
The Right ◽  
Flexor Digitorum

The anterior interosseous nerve is a pure motor branch of the median nerve supplying the flexor pollicis longus, flexor digitorum profundus of the index and middle fingers, and pronator quadratus. Anterior interosseous neuropathy is rare and typically causes weakness of flexion of the tips of the thumb and index finger. Four instrumentalists, 3 violinists and 1 pianist (3 males, 1 female), seen from 1986 to 2002 at our clinic, are the subjects of this report. Age at onset ranged from 16 to 76 yrs. A possible precipitating factor was identified in each. One violinist could not hold the bow; two others noted inability to stabilize the distal left first (index) finger. The pianist noted impaired dexterity of the right hand. Examination showed weakness of flexion of the distal phalanx of the index finger and thumb and variable weakness of forearm pronation. Electrodiagnostic testing confirmed the diagnosis in all four patients. All improved over time. One symphony violinist continued to play for over 15 yrs, despite some persisting difficulty with the left index finger. Another violinist recovered function almost completely but suffered a stroke affecting the opposite hand 2.5 years later. The third violinist retired from the symphony on disability because his recovery was delayed for >1 yr. The young pianist is playing 4 to 5 hrs/day. It is likely that at least three of the four had a localized form of neuralgic amyotrophy.

Electromyographical Analysis of the Extrinsic Muscles of the Long Finger during Pinch Activities

1987 ◽  
Vol 7 (3) ◽  
pp. 163-180 ◽  
Author(s):  
Alice M. Follows
Keyword(s):  
Electrical Activity ◽  
Treatment Guidelines ◽  
Statistical Tests ◽  
Extensor Digitorum ◽  
Flexor Digitorum Profundus ◽  
Flexor Digitorum Superficialis ◽  
Wrist Position ◽  
The Mean ◽  
Flexor Digitorum ◽  
Extrinsic Muscles

Pinch activities commonly used by hand therapists were analyzed electromyographically to determine level of activation of the extensor digitorum (ED), flexor digitorum profundus (FDP), and flexor digitorum superficialis (FDS) of the long finger. The activities were studied with the wrist positioned in flexion and in extension. Statistical tests indicated that the type of pinch elicits a significantly different amount of participation of the FDS but not of the FDP or ED, which contract similarly for the three pinches studied. The mean relative electrical activity of the FDP and ED was affected by wrist position but that of the FDS was not. Treatment guidelines are suggested.

A Cadaveric Study of Needle Insertion at Pc6 in Eight Wrists of Four Subjects and An Understanding of the Anatomy

2012 ◽  
Vol 30 (1) ◽  
pp. 44-46 ◽  
Author(s):  
Hyun Joo Oh ◽  
Yee Kyoung Ko ◽  
Sa Sun Cho ◽  
Sang Pil Yoon
Keyword(s):  
Median Nerve ◽  
Clinical Importance ◽  
Acupuncture Point ◽  
Anatomical Variations ◽  
Needle Insertion ◽  
Flexor Digitorum Profundus ◽  
Pronator Quadratus ◽  
Adjacent Structures ◽  
Median Artery ◽  
Flexor Digitorum

The anatomical structures vulnerable to acupuncture around the PC6 acupuncture point were investigated. Needles were inserted in PC6 of eight wrists from four cadavers to a depth of 2 cm, the forearms were dissected and the adjacent structures around the path of the needles were observed. The needles passed between the tendons of the palmaris longus and flexor carpi radialis muscles and then penetrated the flexor digitorum superficialis, flexor digitorum profundus and pronator quadratus muscles. The inserted needles were located adjacent to the median nerve. To minimise the risk of unintended injury by acupuncture, it is recommended that needles should not be inserted deeply at the PC6 acupuncture point. An understanding of the anatomical variations of the median nerve and the persistent median artery in the forearm is of clinical importance when performing acupuncture procedures.

An Anomaly of the Median Artery Associated with the Anterior Interosseous Nerve Syndrome

1992 ◽  
Vol 17 (5) ◽  
pp. 507-509 ◽  
Author(s):  
T. W. PROUDMAN ◽  
P. J. MENZ
Keyword(s):  
Flexor Digitorum Profundus ◽  
Vascular Compression ◽  
Pronator Quadratus ◽  
Pronator Teres ◽  
Longus Muscle ◽  
Anterior Interosseous Nerve ◽  
Median Artery ◽  
Anterior Interosseous Nerve Syndrome ◽  
Pronator Quadratus Muscle ◽  
Flexor Digitorum

The anterior interosseous nerve syndrome is characterized by paralysis of the flexor pollicis longus muscle, the flexor digitorum profundus muscle to the index and middle fingers, and the pronator quadratus muscle. The most common cause is entrapment of the anterior interosseous nerve near its origin from the median nerve by a variety of structures. Compression is most frequently caused by the deep head of the pronator teres muscle, or the fibrous arcade of the flexor digitorum superficialis muscle. Vascular compression has been reported infrequently. A patient with anterior interosseous nerve syndrome was found at operation to have the median artery passing through the anterior interosseous nerve just below the elbow. This artery has not previously been associated with the syndrome. A cadaver dissection confirmed the relationship.

ANTERIOR INTEROSSEOUS NERVE SYNDROME

Hand Surgery ◽  
1998 ◽  
Vol 03 (01) ◽  
pp. 57-62 ◽  
Author(s):  
Gary L. Arishita ◽  
Tsu-Min Tsai
Keyword(s):  
Conservative Treatment ◽  
Upper Extremity ◽  
Surgical Decompression ◽  
Flexor Digitorum Profundus ◽  
Flexor Pollicis Longus ◽  
Pronator Quadratus ◽  
Steroid Injections ◽  
Anterior Interosseous Nerve ◽  
Anterior Interosseous Nerve Syndrome ◽  
Flexor Digitorum

The anterior interosseous nerve syndrome was first described in 1948. It comprises less than 1% of all upper extremity nerve palsies. Patients have a characteristic pinch deformity, with paralysis or weakness of the muscles innervated by the anterior interosseous nerve, flexor pollicis longus, radial portion of the flexor digitorum profundus, and pronator quadratus. Electromyograms are positive in most patients presenting with motor complaints. Treatment is related to the specific etiology. Conservative treatment includes avoidance of strenuous forearm work, immobilization, steroid injections, and anti-inflammatory medications. If the presentation suggests nerve compression, and the EMG reveals evidence of axonal interruption, then surgical decompression should be performed. We present a series of six patients seen over a 7-year period. Improvement was noted in all the patients postoperatively.

Mesotendons of Digital Flexor Muscles and Their Vasculature

HAND ◽  
1981 ◽  
Vol os-13 (3) ◽  
pp. 231-238 ◽  
Author(s):  
A. Zbrodowski ◽  
S. Gajisin ◽  
J. Grodecki
Keyword(s):  
Blood Supply ◽  
Flexor Digitorum Profundus ◽  
Gelatin Solution ◽  
Flexor Digitorum Superficialis ◽  
Arterial Network ◽  
India Ink ◽  
Flexor Muscles ◽  
Different Types ◽  
Human Cadavers ◽  
Flexor Digitorum

The detailed anatomy of the tendinous apparatus of the flexor digitorum profundus and flexor digitorum superficialis muscles was studied on 150 fresh and formalin-preserved human cadavers. The dissection revealed the existence of different types of mesotendons. Injection of coloured latex or an India ink and gelatin solution showed their arterial network and the sources of blood supply.

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