Bones and joints
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings in McMinn’s Concise Human Anatomy, 2017
Humerus - bone of the arm, with a rounded head at the proximal end: the greater tubercle (tuberosity) at the outer lateral side of the head, the lesser tubercle (tuberosity) anteriorly, with the intertubercular (bicipital) groove between them located anteriorly on the proximal end of the shaft (Fig.2.6). The margin of the smooth head is the anatomical neck; between the proximal part of the shaft and the head (and tubercles) is the surgical neck (as this is the commoner site for fractures in this region of the humerus). At the distal end there is a prominent medial epicondyle and a less obvious lateral epicondyle. Between the two are the smooth articular surfaces for the elbow joint: medially, the pulley-shaped trochlea (for the ulna) with a prominent medial lip; and laterally, the rounded capitulum (for the radius). Posteriorly at the distal end is the deep olecranon fossa, which accommodates the olecranon of the ulna when the elbow is extended.
Upper Limb Muscles
Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo in Handbook of Muscle Variations and Anomalies in Humans, 2022
Standring (2016) reports that variation in subscapularis is not common, while Lamb (2016) states that this muscle has the most reported variations of any of the rotator cuff muscles. In addition to the lesser tubercle, its tendon can insert into the bicipital groove or greater tubercle (MacDonald et al. 2007; Cash et al. 2009; Lamb 2016). Subscapularis can divide into two discrete parts or numerous slips (Macalister 1867a, 1875; Lamb 2016). Subscapularis may connect with biceps brachii, pectoralis major, or triceps brachii (Macalister 1875; Le Double 1897; Bergman et al. 1988; Lamb 2016). Mori (1964) found an abnormal slip that extended from levator scapulae to subscapularis. Coracobrachialis profundus may insert into subscapularis or its tendon (Macalister 1875; Knott 1883a). Le Double (1897) describes a slip that originated from the subscapular tendon and attached to the axillary fascia or skin. An accessory slip may extend from the shoulder joint capsule and lesser tubercle and insert onto latissimus dorsi (Namking et al. 2013).
Deltoid and Scapular Regions
Gene L. Colborn, David B. Lause in Musculoskeletal Anatomy, 2009
The Rotator Cuff. The tendons of insertion of the supraspinatus, infraspinatus and teres minor muscles form the external, or lateral portion of the muscular “rotator cuff” of the shoulder in their collective passage about the capsule of the shoulder joint and insertion upon the greater tubercle of the humerus. This tendinous portion of the rotator cuff is subject to damage in common, often highly debilitating tears (which can quickly end a professional career in sports). With aging, there is in many individuals a gradual reduction in vascular supply to these tissues - increasing the likelihood of injuries which heal only slowly and often poorly.
A custom-made distal humerus plate fabricated by selective laser melting
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Thansita Thomrungpiyathan, Suriya Luenam, Boonrat Lohwongwatana, Winai Sirichativapee, Kriengkrai Nabudda, Chedtha Puncreobutr
Computational simulations were performed with a compression load of 200 N in axial direction on the distal end of humerus bone (Sabalic et al. 2013; Kudo et al. 2016). Note that the load is also in a testing range to evaluate load bearing in primary rehabilitation (Varady et al. 2017). As shown in Figure 2, the load was applied on surfaces of capitellum and trochlea in all models. The proximal end of humerus bone, include greater tubercle, lesser tubercle and intertubercular groove was defined as fixed support. As suggested in previous study (Bogataj et al. 2015), bolt pretension load of 10 N was also applied to all screws. Two types of contact conditions were defined. Contact interactions that allow finite sliding with zero friction coefficient (no separation constraint) were defined between the bone and the plates as well as between the screws and plate. Bonded contact constraint was applied between the screws and the surrounding bone as well as between the cortical bone and the trabecular bone.
Everything pectoralis major: from repair to transfer
Published in The Physician and Sportsmedicine, 2020
Kamali Thompson, Young Kwon, Evan Flatow, Laith Jazrawi, Eric Strauss, Michael Alaia
The pectoralis major tendon is advantageous for transfer as it has the second longest excursion of 18.8 cm33. There are various surgical approaches to a pectoralis major transfer including superficial to conjoint transfer, deep to conjoint, split, whole muscle, and sternal head transfer [72]. Rockwood and Wirth first described the pectoralis major muscle transfer using the superficial to conjoint transfer technique [72]. The release of the superior 3 cm of the tendon is released from the insertion on the greater tubercle of the humerus and sutured into the lateral edge of the bone trough [72]. Resch describes both the split and whole muscle transfer techniques [70]. The split technique transfers the superior two-thirds of the pectoralis major tendon under the conjoined tendon to mimic the subscapularis, whereas the whole muscle technique involves transferring the entire tendon [70]. Warner’s technique transfers the inferior portion of the sternal head deep to the clavicular head and superficial to the conjoined tendon into the lesser tuberosity in order to avoid the musculocutaneous nerve [71]. Klepps modified Resch’s subcoracoid transfer by transferring the entire tendon deep to the conjoint tendon, superficial to musculocutaneous nerve, and attaching it the tendon to the greater tuberosity [73].
Feasibility and significance of stimulating interscapular muscles using transcutaneous functional electrical stimulation in able-bodied individuals
Published in The Journal of Spinal Cord Medicine, 2021
Naaz Kapadia, Bastien Moineau, Melissa Marquez-Chin, Matthew Myers, Kai Lon Fok, Kei Masani, Cesar Marquez-Chin, Milos R. Popovic
The current study results showed that while there was a wide variation in the range of shoulder movements across all able-bodied participants, stimulating the scapular muscles resulted in higher arm reach in abduction. However, it did not have any significant impact on the range of arm reach in flexion. Overall, irrespective of the muscles being stimulated, the maximum reach as well as percent of voluntary movement achieved in flexion was greater than that in abduction. It is important to note that in able-bodied individuals the contribution of scapular movement to total arm elevation varies widely across individuals30; and this could have potentially resulted in the wide variations in the range of motion recorded across participants and across various experimental conditions. Since the movement of the arm started with the shoulder in neutral rotation, it allowed for clearance of the greater tubercle under the acromion during forward flexion. However, it may have restricted its clearance during abduction,12 resulting in decreased range. Secondly, we found that for abduction the maximum reach achieved with FES of scapular muscles along with middle deltoid was greater compared to the stimulation of middle deltoid alone. In abduction, the force of the trapezius is more critical to produce upward rotation of the scapula than the force of the SA.12 Given the superficial location and size of the trapezius, and the fact that there were total four electrodes (two channels) dedicated to the trapezius muscle, this might have resulted in increased contribution of the muscle toward the movement produced. This is important for patients with high cervical spine injury for two reasons. First, the shoulder complex biomechanics is altered in these patients secondary to paralysis/weakness of the deltoid and second, shoulder abduction and scapulothoracic upward rotation are critical for the execution of ADLs.21
Related Knowledge Centers
- Infraspinatus Muscle
- Palpation
- Shoulder Joint
- Subscapularis Muscle
- Supraspinatus Muscle
- Rotator Cuff
- Humerus
- Teres Minor Muscle
- Lesser Tubercle
- Bicipital Groove