Jospt march 1987 kinesiology of the shoulder table 3 muscle actions at the shoulder complex muscle biceps brachii long head may abduct the humerus if the humerus is externally rotated. If the clavicle is not allowed to rotate, elevation of only about 110 degrees is said to be possible. Glenohumeral joint anatomy, stabilizer, and biomechanics. Static stabilizers include the bony anatomy, negative intraarticular pressure, the glenoid labrum, and the glenohumeral ligaments along with the joint capsule. Chapter 6 biomechanics of the shoulder eiji itoi, md, phd, bernard f. Pdf biomechanical basis of common shoulder problems. The predominant importance of the capsuloligamentous and muscular structures over the osteoarticular components increases the mechanical refinement of this balance. Biomechanics according to millers anatomy, the teres major muscle acts to flex the shoulder joint. To make the subject at once comprehensive and relevant to the clinician, the structure and function of the sternoclavicular and acromioclavicular joints are dealt with first. The biomechanics of the shoulder joint has been an active area of study for many years. O n the other hand, the shoulder com plex is com posed of the scapulothoracic articulation and the glenohum eral joint to.
Biomechanics has all kinds of practical applications from the construction of running shoes to ankle braces to lowback pain to weightlifting. The shoulder has the greatest range of movement of any human joint. The loosepacked positions allow for better joint lubrication, less frictional forces on the joint sur faces, and more freedom of movement through combined joint surface spin, roll, and slide. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Clinical anatomy and biomechanics of the glenohumeral. Only sc joint connects the components of shoulder joint to the axial skeleton. In this section, we explain shoulder biomechanics focusing on the.
Axial rotation of the clavicle is reported by inman and coworkers to be an essential and fundamental feature of shoulder motion, particularly arm elevation fig. Flexion is motion in the anterior direction for joints of the head, neck, trunk, upper extremity, and hips figure 24, a. Biomechanics of the shoulder complex look at how the entire shoulder complex moves and start to get a feel for where the restrictions are and where they compensate. More than a glenohumeral joint, the shoulder complex consists of four joints and numerous muscles and ligaments. These changes may affect the biomechanics of the shoulder and alter the shoulder joint inducing loss of power and pain according to the underlaying pathology. The shoulder is an intricate multidimensional joint complex consisting of four separate connection points of bones responsible for the movement of the hand, arm and shoulder. Flexionextension the normal range of elbow motion in.
The biomechanics of current reverse shoulder replacement. The biomechanics of the glenohumeral joint depend on the interaction of both static and dynamicstabilizing structures. Acromioclavicular ac joint injuries are more common than sternoclavicular sc joint injuries. There is a spectrum of ac joint traumatic injuries that ranges from a ligament sprain to a complete dislocation. Relocation test instead of bringing arm back to neutral, put hand over shoulder to provide anterior support that they need and relocate it 3. Biomechanics of the shoulder in this section, we explain shoulder biomechanics focusing on the rotator cuff muscles, and describe the concept of rotator cuff repair in the next section. Introduction the shoulder is composed of 3 synovial joints. Glenohumeral joint anatomy, stabilizer, and biomechanics 12212018 201 views.
The shoulder s ability for multiple degrees of motion is based on the interaction of multiple structures that react to mechanical stimuli and adjust accordingly. Yoga asana instruction often oversimplifies important actions in the shoulder, but since we spend significant time placing weight through the hands and therefore the shoulders in yoga, and its wise. Biomechanics of the shoulder joint jama surgery jama. The glenohumeral joint has six degrees of freedom of motion, which can be. Elbow biomechanics kinematics together with the shoulder, the elbow acts to position the hand in space. Trunk head neck shoulders arms wrist hands trunk head neck structure of the shoulder sternoclavicular joint. It discusses bones, ligaments, muscles and other structures that make up the shoulder joint. Pdf on jan 1, 20, deepak patkar and others published anatomy and biomechanics of shoulder joint find, read and cite all the research you. Compared to the shoulder, which has a large range of motion in all three axes of rotation, elbow range of motion is relatively constrained. A force couple is defined as two equal but oppositely directed forces acting simultaneously on opposite sides of an axis that generates rotation. To enable this there is less constraint than in other joints. The approach of the biomechanical engineer is thus difficult to begin with as regards mechanical investigation of the shoulder systems motion, and becomes doubly so when the subject of investigation is the systems instability. The shoulder, being the most mobile joint of the human body, is highly susceptible to injury 1. Biomechanics and assessment of the painful shoulder.
In order to better understand the biomechanics of the shoulder it is important to understand its anatomy. It is important to reevaluate functional mechanics before and after each treatment intervention. In mechanics, a couple is a system of forces that results in a moment without a resultant force and creates a. Lennard funk the shoulder is potentially one of the most unstable joints of the body, with very little bony stability or containment and has been likened to a golf ball on a golf tee. Research from jama surgery biomechanics of the shoulder joint. Mar 30, 2016 the shoulder consists of two force couples.
The two main bones of the shoulder are the humerus and the scapula shoulder blade. To make the subject at once comprehensive and relevant to the clinician, the structure and function of the sternoclavicular and acromioclavicular. Since the introduction of reverse shoulder arthroplasty rsa over 40 years ago, many prosthesis designs have endeavored to improve shoulder pain and function in patients with challenging conditions such as massive rotator cuff tears, cuff tear arthropathy, proximal humerus fractures, and inflammatory arthropathy. Mar 31, 2020 the shoulder is an intricate multidimensional joint complex consisting of four separate connection points of bones responsible for the movement of the hand, arm and shoulder. Shoulder biomechanics and exercises medbridge blog. Understand the normal biomechanics of the shoulder. Oct 16, 2016 introduction the shoulder is composed of 3 synovial joints. Sc joint connects the components of shoulder joint to the axial skeleton. Biomechanical summary of reverse shoulder arthroplasty. Review anatomy of shoulder complex and its function.
Morrey, md, kainan an, phd because of its component parts, a description of the biomechanics of the shoulder complex is rather involved. The majority of ac joint injuries are successfully treated nonoperatively with a period of sling immobilisation followed by progressive physical therapy and shoulder range of motion. It is important to reevaluate functional mechanics. More than a glenohumeral joint, the shoulder complex consists of four joints and. Because of the hinge effect, the del toid forces the humerus upward on the glenoid at 0 of abduction as abduction at the glenohumeral joint progresses, the pull of. Biomechanics and treatment of acromioclavicular and. Biomechanics of the shoulder joint jama surgery jama network. Bio mechanics of the shoulder free download as powerpoint presentation. Balancing mobility and stability, the biomechanics of the shoulder provides optimal use of the thumb and hand. Jospt janlfeb 1985 biomechanics of the shoulder figure lb the right scapula.
Kinematics describes the motion of objects without consideration of the causes leading to the motion biomechanics. Please read the section on basic shoulder anatomy before reading this section. The biomechanics of the shoulder is how the shoulder moves, as well as the scientific study of this movement. The shoulder complex involves 3 physiological joints and one floating joint. Flexion of the knee, ankle, foot, and toes is movement in the posterior direction. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Knowing how the body moves because of the forces applied to the body is key to getting the most out of your athletic performance, and your daily life. Athletes often incur injuries of the shoulder as they subject the joint to extreme ranges of motion and force, as. Chapter 5 the shoulder joint manual of structural kinesiology r.
This chapter concentrates on the physiological range of motion and the different stabilizing and anatomical aspects of the shoulder. Instability of the glenohumeral joint the shoulder system provides a wide range of motion, to the detriment of stability. Shoulder girdle permits largest rom of any complex in the body shoulder girdle increases rom with less compromise of stability scapulohumeral rhythm 4 joints vs. Shoulder joint is attached to axial skeleton via the clavicle at.
Apprehension test lay on back, shoulder in 90 degree abduction, elbow is 90 degree flexion and put strain on anterior shoulder. The scapula extends up and around the shoulder joint at the rear to form a roof called the acromion, and around the shoulder joint at the front to form the coracoid process. The latissimus dorsi, serratus anterior, pectoralis major, and del. Scapulothoracic muscles the stability of the glenohumeral joint is also affected by the large muscles acting away from the shoulder joint itself. Anatomy and biomechanics of the shoulder journal of hand therapy. T he joints of the shoulder com plex have to rely on adjacent ligam ents and m uscles to provide stability.
This generous amount of mobility can lead to a multitude of intrinsic ailments about the shoulder and, in fact, a majority of shoulder problems stem from this relative lack of bony stability. Introduction shoulder joint gh joint has more mobility than stability. Renee thiebaud, phd, pt the orthopedic store physical therapy the basics upper extremity includes. Glenohumeral joint anatomy, stabilizer, and biomechanics ft. The biomechanics of the shoulder is how the shoulder moves, as. To effectively rehabilitate a shoulder injury in clinical practice, it is important to have a functional knowledge of the underlying biomechanics of the shoulder complex. The shoulder joint is unique, as multiplanar mobility of the joint is dominant over static stability. At 60 of abduction, the downward short rotator force was maximal at 9. The biomechanics of current reverse shoulder replacement options. Biomechanical summary of reverse shoulder arthroplasty youtube.
Its base is attached to the m ar gin of the glenoid fossa by fibrocartilage and fibrous bone. Shooting technique and biomechanics 15 bow arm, shoulder joint, elbow and wrist 19 head position and spine 22 drawing arm, shoulder, elbow and wrist 23 compound archer 24 release 25 drawing technique 25 predraw 26 bow shoulder 26 drawing the bow 26. Edgehughes, lm anatomy, biomechanics, physiology, diagnosis and treatment of teres major strains in the canine. The rotator cuff muscles work not only as a motion actuator abduction or external and internal rotations but also as a shoulder stabilizer. In this section, we explain shoulder biomechanics focusing on the rotator cuff muscles, and describe the concept of rotator cuff repair in the next section. Deltoid force was maximal with the arm abducted 90, and was calculated to be 8. The complex biomechanics of the shoulder can be very difficult to unravel.
Identify the correct motion within the plane of the scapula when assessing and treating the shoulder. Biomechanics of the shoulder complex free download as powerpoint presentation. The purpose of this manuscript is to identify recent advances in understanding of normal and abnormal biomechanics of the shoulder as related to rehabilitation of shoulder impingement. Clinical anatomy and biomechanics of the glenohumeral joint. Biomechanics of the shoulder during throwing american sports medicine. Biomechanics of the shoulder and elbow orthopaedics and trauma. Since the other joints of the shoulder girdle can accept these forces and move, stabilization of the appropriate bony ele ments is imperative for jointspecific. The axis around which movement takes chapter 2 joint anatomy and basic biomechanics figure 22 a, midsagittal plane. Identify abnormal biomechanics of the shoulder and how dysfunction disrupts function at varying stages of motion.
The glenohumeral joint provides the largest range of motion among all diarthrodial joints but also has the greatest propensity for instability. Analyze overall mechanical effects on shoulder during movement. It is the strongest ligament in the body with a tensile strength greater than 350n 6. This puts greater demands on the muscles for securing the shoulder girdle. There is a fine balance between the mobility to perform athletic activities and stability required to power and stabilise the arm. Shoulder biomechanics lecture originally developed by bryan morrison, ph. Biomechanics of the shoulder girdle audio and pdf yoga. Shoulder instability biomechanics shoulderdoc by prof. Chapter 1 clinical anatomy and biomechanics of the glenohumeral joint including stabilizers thay q.