The rotator cuff (SITS muscles) is a group of

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

s and their

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

s that act to stabilize the human

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder m ...

and allow for its extensive

range of motion Range of motion (or ROM) is the linear or angular distance that a moving object may normally travel while properly attached to another. In biomechanics and strength training, ROM refers to the angular distance and direction a joint can move be ...

. Of the seven

scapulohumeral muscles The scapulohumeral muscles are a group of seven muscles that connect the humerus to the scapula. They are amongst the muscles that act on and stabilise the glenohumeral joint in the human body. They include : *coracobrachialis muscle *deltoid m ...

, four make up the rotator cuff. The four muscles are: *

supraspinatus muscle The supraspinatus (: supraspinati) is a relatively small muscle of the upper back that runs from the supraspinous fossa superior portion of the scapula (shoulder blade) to the greater tubercle of the humerus. It is one of the four rotator cuff mus ...

infraspinatus muscle In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.''Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspin ...

teres minor muscle The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...

subscapularis muscle The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. Structure The subscapularis is covered by a dense fasci ...

Structure

Muscles composing rotator cuff

The supraspinatus muscle spreads out in a horizontal band to insert on the superior facet of the

greater tubercle The greater tubercle of the humerus is the outward part the upper end of that bone, adjacent to the large rounded prominence of the humerus head. It provides attachment points for the supraspinatus, infraspinatus, and teres minor muscles, th ...

of the

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

. The greater tubercle projects as the most

lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...

structure of the humeral head.

Medial Medial may refer to: Mathematics * Medial magma, a mathematical identity in algebra Geometry * Medial axis, in geometry the set of all points having more than one closest point on an object's boundary * Medial graph, another graph that repr ...

to this, in turn, is the

lesser tubercle The lesser tubercle of the humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of thre ...

of the humeral head. The subscapularis muscle

origin Origin(s) or The Origin may refer to: Arts, entertainment, and media Comics and manga * ''Origin'' (comics), a Wolverine comic book mini-series published by Marvel Comics in 2002 * ''The Origin'' (Buffy comic), a 1999 ''Buffy the Vampire Sl ...

is divided from the remainder of the rotator cuff origins as it is deep to the

scapula The scapula (: scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either side ...

. The four

s of these muscles converge to form the rotator cuff tendon. These tendinous insertions along with the

articular capsule In anatomy, a joint capsule or articular capsule is an envelope surrounding a synovial joint.coracohumeral ligament, and the glenohumeral ligament complex, blend into a confluent sheet before insertion into the humeral tuberosities (i.e. greater and lesser tubercle). The infraspinatus and teres minor fuse near their musculotendinous junctions, while the supraspinatus and subscapularis tendons join as a sheath that surrounds the

biceps The biceps or biceps brachii (, "two-headed muscle of the arm") is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Both heads of the muscle arise on the scapula and join to form a single muscle bel ...

tendon at the entrance of the bicipital groove. The supraspinatus is most commonly involved in a

rotator cuff tear Rotator cuff tendinopathy is a process of senescence. The pathophysiology is mucoid degeneration. Most people develop rotator cuff tendinopathy within their lifetime. As part of rotator cuff tendinopathy, the tendon can thin and develop a defec ...

Function

The rotator cuff muscles are important in shoulder movements and in maintaining

glenohumeral joint The shoulder joint (or glenohumeral joint from Greek ''glene'', eyeball, + -''oid'', 'form of', + Latin ''humerus'', shoulder) is structurally classified as a synovial ball-and-socket joint and functionally as a diarthrosis and multiaxial joint ...

(shoulder joint) stability. These muscles arise from the

and connect to the head of the

, forming a cuff at the shoulder joint (hence the name rotator cuff). They hold the head of the humerus in the small and shallow glenoid fossa of the scapula. The glenohumeral joint has been analogously described as a

golf ball A golf ball is a ball designed to be used in golf. Under the rules of golf, a golf ball has a mass no more than , has a diameter not less than , and performs within specified velocity, distance, and symmetry limits. Like golf clubs, golf bal ...

(head of the humerus) sitting on a golf tee (glenoid fossa). The rotator cuff compresses the glenohumeral joint during abduction of the arm, an action known as concavity compression, in order to allow the large

deltoid muscle The deltoid muscle is the muscle forming the rounded contour of the shoulder, human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle is made up o ...

to further elevate the arm. In other words, without the rotator cuff, the humeral head would ride up partially out of the glenoid fossa, lessening the efficiency of the deltoid muscle. The anterior and posterior directions of the glenoid fossa are more susceptible to

shear force In solid mechanics, shearing forces are unaligned forces acting on one part of a Rigid body, body in a specific direction, and another part of the body in the opposite direction. When the forces are Collinearity, collinear (aligned with each ot ...

perturbations, as the glenoid fossa is not as deep relative to the superior and inferior directions. The rotator cuff's contributions to concavity compression and stability vary according to their stiffness and the direction of the force they apply upon the joint. In addition to stabilizing the glenohumeral joint and controlling humeral head translation, the rotator cuff muscles also perform multiple functions, including abduction,

internal rotation Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...

, and external rotation of the shoulder. The infraspinatus and subscapularis have significant roles in scapular plane shoulder abduction ( scaption), generating forces that are two to three times greater than the force produced by the supraspinatus muscle. However, the supraspinatus is more effective for general shoulder abduction because of its

moment arm In physics and mechanics, torque is the rotational analogue of linear force. It is also referred to as the moment of force (also abbreviated to moment). The symbol for torque is typically \boldsymbol\tau, the lowercase Greek alphabet, Greek let ...

. The anterior portion of the supraspinatus tendon is submitted to a significantly greater load and stress, and performs its main functional role.

Clinical significance

Tear

The tendons at the ends of the rotator cuff muscles can become torn, leading to

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

and restricted movement of the arm. A torn rotator cuff can occur following trauma to the shoulder or it can occur through the "wear and tear" on tendons, most commonly the supraspinatus tendon found under the

acromion In human anatomy, the acromion (from Greek: ''akros'', "highest", ''ōmos'', "shoulder", : acromia) or summit of the shoulder is a bony process on the scapula (shoulder blade). Together with the coracoid process, it extends laterally over the sh ...

. Rotator cuff injuries are commonly associated with motions that require repeated overhead motions or forceful pulling motions. Such injuries are frequently sustained by athletes whose actions include making repetitive throws, athletes such as handball players,

baseball Baseball is a bat-and-ball games, bat-and-ball sport played between two team sport, teams of nine players each, taking turns batting (baseball), batting and Fielding (baseball), fielding. The game occurs over the course of several Pitch ...

pitcher In baseball, the pitcher is the player who throws ("Pitch (baseball), pitches") the Baseball (ball), baseball from the pitcher's mound toward the catcher to begin each play, with the goal of out (baseball), retiring a batter (baseball), batter, ...

softball Softball is a Variations of baseball, variation of baseball, the difference being that it is played with a larger ball, on a smaller field, and with only underhand pitches (where the ball is released while the hand is primarily below the ball) ...

pitchers,

American football American football, referred to simply as football in the United States and Canada and also known as gridiron football, is a team sport played by two teams of eleven players on a rectangular American football field, field with goalposts at e ...

players (especially

quarterback The quarterback (QB) is a position in gridiron football who are members of the offensive side of the ball and mostly line up directly behind the Lineman (football), offensive line. In modern American football, the quarterback is usually consider ...

s),

firefighter A firefighter (or fire fighter or fireman) is a first responder trained in specific emergency response such as firefighting, primarily to control and extinguish fires and respond to emergencies such as hazardous material incidents, medical in ...

cheerleaders Cheerleading is an activity in which the participants (called cheerleaders) cheer for their team as a form of encouragement. It can range from chanting slogans to intense physical activity. It can be performed to motivate sports teams, to ent ...

, weightlifters (especially powerlifters due to extreme weights used in the

bench press The bench press or chest press is a weight training exercise where a person presses a weight upwards while lying horizontally on a weight training bench. The bench press is a Compound movements, compound movement, with the primary muscles involved ...

), rugby players,

volleyball Volleyball is a team sport in which two teams of six players are separated by a net. Each team tries to score points by grounding a ball on the other team's court under organized rules. It has been a part of the official program of the Summ ...

players (due to their swinging motions),

water polo Water polo is a competitive sport, competitive team sport played in water between two teams of seven players each. The game consists of four quarters in which the teams attempt to score goals by throwing the water polo ball, ball into the oppo ...

players, rodeo team ropers,

shot put The shot put is a track-and-field event involving "putting" (throwing) a heavy spherical Ball (sports), ball—the ''shot''—as far as possible. For men, the sport has been a part of the Olympic Games, modern Olympics since their 1896 Summer Olym ...

throwers,

swimmers Swimming is an individual or team racing sport that requires the use of one's entire body to move through water. The sport takes place in pools or open water (e.g., in a sea or lake). Competitive swimming is one of the most popular Olympic ...

, boxers, kayakers,

martial artists Martial arts are codified systems and traditions of combat practiced for a number of reasons such as self-defence; military and law enforcement applications; competition; physical, mental, and spiritual development; entertainment; and the prese ...

fast bowlers Fast bowling (also referred to as pace bowling) is a type of bowling in cricket, in which the ball is delivered at high speed. The fastest bowlers bowl the ball at over . Practitioners of fast bowling are known as fast bowlers or quicks. Also ...

in cricket,

tennis Tennis is a List of racket sports, racket sport that is played either individually against a single opponent (singles (tennis), singles) or between two teams of two players each (doubles (tennis), doubles). Each player uses a tennis racket st ...

players (due to their service motion) and tenpin bowlers due to the repetitive swinging motion of the arm with the weight of a

bowling ball A bowling ball is a hard spherical ball used to knock down bowling pins in the sport of bowling. Balls used in ten-pin bowling and American nine-pin bowling traditionally have holes for two fingers and the thumb. Balls used in five-pin bowlin ...

. This type of injury also commonly affects orchestra conductors, choral conductors, and

drummer A drummer is a percussionist who creates music using drums. Most contemporary western music ensemble, bands that play Rock music, rock, Pop music, pop, jazz, or Contemporary R&B, R&B music include a drummer for purposes including timekeepi ...

s (due, again, to swinging motions). As progression increases after 4–6 weeks, active exercises are now implemented into the rehabilitation process. Active exercises allow an increase in strength and further range of motion by permitting the movement of the shoulder joint without the support of a physical therapist. Active exercises include the Pendulum exercise, which is used to strengthen the Supraspinatus, Infraspinatus, and Subscapularis. External rotation of the shoulder with the arm at a 90-degree angle is an additional exercise done to increase control and range of motion of the Infraspinatus and Teres minor muscles. Various active exercises are done for an additional 3–6 weeks as progress is based on an individual case-by-case basis. At 8–12 weeks,

strength training Strength training, also known as weight training or resistance training, is exercise designed to improve physical strength. It is often associated with the lifting of Weightlifting, weights. It can also incorporate techniques such as bodyweigh ...

intensity will increase as free-weights and resistance bands will be implemented within the exercise prescription.

Impingement

The accuracy of the physical examination is low. The Hawkins-Kennedy test has a sensitivity of approximately 80% to 90% for detecting impingement. The infraspinatus and supraspinatus tests have a specificity of 80% to 90%. A common cause of shoulder pain in rotator cuff impingement syndrome is

tendinosis Tendinopathy is a type of tendon disorder that results in pain, swelling, and impaired function. The pain is typically worse with movement. It most commonly occurs around the shoulder ( rotator cuff tendinitis, biceps tendinitis), elbow (tenni ...

, which is an age-related and most often self-limiting condition. Studies show that there is moderate evidence that hypothermia (cold therapy) and exercise therapy used together are more effective than simply waiting for surgery and they suggest the best outcome for non-surgical treatment of subacromial impingement syndrome. The group of patients who participated in the exercise group were found to use significantly lower amounts of non-steroidal anti-inflammatory drugs (NSAIDS) and analgesics than the control group with no intervention.

Inflammation and fibrosis

The rotator interval is a triangular space in the shoulder that is functionally reinforced externally by the coracohumeral ligament and internally by the superior glenohumeral ligament, and traversed by the intra-articular biceps tendon. On imaging, it is defined by the coracoid process at its base, the supraspinatus tendon superiorly and the subscapularis tendon inferiorly. Changes of adhesive capsulitis can be seen at this interval as

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

and

fibrosis Fibrosis, also known as fibrotic scarring, is the development of fibrous connective tissue in response to an injury. Fibrosis can be a normal connective tissue deposition or excessive tissue deposition caused by a disease. Repeated injuries, ch ...

. Pathology at the interval is also associated with glenohumeral and biceps instability. Adhesive capsulitis or "frozen shoulder" is often secondary to rotator cuff injury due to post-surgical immobilization. Available treatment options include intra-articular corticosteroid injections to relieve pain in the short-term and electrotherapy, mobilizations, and home exercise programs for long-term pain relief.

Pain management

Treatment for a rotator cuff tear can include rest, ice, physical therapy, and/or surgery. A review of manual therapy and exercise treatments found inconclusive evidence as to whether these treatments were any better than placebo, however "High quality evidence from one trial suggested that manual therapy and exercise improved function only slightly more than placebo at 22 weeks, was little or no different to placebo in terms of other patient-important outcomes (e.g. overall pain), and was associated with relatively more frequent but mild adverse events." The rotator cuff includes muscles such as the supraspinatus muscle, the

infraspinatus In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.''Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspin ...

muscle, the

and the

. The upper arm consists of the deltoids,

, as well as the

triceps The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the ventral, back of the upper limb of many vertebrates. It consists of three parts: the medial, lateral, and long head. All three heads cross the ...

. Steps must be taken and precautions need to be made in order for the rotator cuffs to heal properly following surgery while still maintaining function to prevent any deteriorating effects on the muscles. In the immediate postoperative period (within one week following surgery), pain can be treated with a standard ice wrap. There are also commercial devices available which not only cool the shoulder but also exert pressure on the shoulder ("compressive cryotherapy"). However, one study has shown no significant difference in postoperative pain when comparing these devices to a standard ice wrap.

Continuous passive motion

Physiotherapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

can help manage the pain, but utilizing a program that involves continuous passive motion will reduce the pain even further. Assisted passive motion at a low intensity allows the tissues to be stretched slightly without damaging themPlessis, M. Du, E. Eksteen, A. Jenneker, E. Kriel, C. Mentoor, T. Stucky, D. Van Staden, and L. Morris. "The Effectiveness of Continuous Passive Motion on Range of Motion, Pain and Muscle Strength following Rotator Cuff Repair: A Systematic Review." Clinical Rehabilitation (2011): 291-302

Continuous passive motion Continuous passive motion (CPM) devices are used during the first phase of rehabilitation following a soft tissue surgical procedure or trauma. The goals of phase 1 rehabilitation are: control post-operative pain, reduce inflammation, provide pass ...

improves the shoulder range and enables the subject to expand their range of motion without experiencing additional pain. Easing into the motions will allow the person to continue working those muscles to keep them from undergoing atrophy, while also still maintaining that minimum level of function where daily function is allowed. Doing these exercises will also prevent tears in the muscles that will impair daily function further.

Manual therapy

A systematic review and

meta-analysis Meta-analysis is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, th ...

study shows

manual therapy Manual therapy, or manipulative therapy, is a treatment primarily used by physical therapists, occupational therapists, and massage therapists to treat musculoskeletal pain and disability. It mostly includes kneading and manipulation of muscle ...

may help to reduce pain for patient with Rotator cuff tendiopathy, based on low- to moderate-quality evidence. However, there is not strong evidence for improving function also.

Surgery

Surgical approaches include acromioplasty (a part of the bone is removed to decrease pressure placed on the rotator cuff tendons), removal of a bursa that is inflamed or swollen, and subacromial decompression (the removal of tissue or bone that is damaged in order to allow more space for the tendons). Surgery may be recommended for patients with an acute, traumatic rotator cuff tear resulting in substantial weakness. Surgery can be performed open or arthroscopically, although the arthroscopic approach has become much more popular. If a surgical option is selected, the rehabilitation of the rotator cuff is necessary in order to regain maximum strength and range of motion within the shoulder joint.

Physical therapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

progresses through four stages, increasing movement throughout each phase. The tempo and intensity of the stages are solely reliant on the extent of the injury and the patient's activity necessities. The first stage requires immobilization of the

shoulder joint The shoulder joint (or glenohumeral joint from Greek ''glene'', eyeball, + -''oid'', 'form of', + Latin ''humerus'', shoulder) is structurally classified as a synovial joint, synovial ball-and-socket joint and functionally as a diarthrosis and m ...

. The shoulder that is injured is placed in a sling and shoulder flexion or abduction of the arm is avoided for 4 to 6 weeks after surgery (Brewster, 1993). Avoiding movement of the shoulder joint allows the torn tendon to fully heal. Once the

is entirely recovered, passive exercises can be implemented. Passive exercises of the shoulder are movements in which a physical therapist maintains the arm in a particular position, manipulating the rotator cuff without any effort by the patient. These exercises are used to increase stability, strength and range of motion of the subscapularis, supraspinatus, infraspinatus, and teres minor muscles within the rotator cuff. Passive exercises include internal and external rotation of the shoulder joint, as well as flexion and extension of the shoulder. A 2019 Cochrane Systematic Review found with a high degree of certainty that subacromial decompression surgery does not improve pain, function, or quality of life compared with a placebo surgery.

Orthotherapy exercises

Patients that suffer from pain in the rotator cuff may consider utilizing orthotherapy into their daily lives. Orthotherapy is an exercise program that aims to restore the motion and strength of the shoulder muscles.Wirth, Michael A., Carl Basamania, and Charles A. Rockwood. "Nonoperative Management of Full-Thickness Tears of the Rotator Cuff." Orthopedic Clinics of North America (1997): 59-67 Patients can go through the three phases of orthotherapy to help manage pain and also recover their full range of motion in the rotator cuff. The first phase involves gentle stretches and passive all around movements, and people are advised not to go above 70 degrees of elevation to prevent any kind of further pain. The second phase of this regimen requires patients to implement exercises to strengthen the muscles that are surrounding the rotator cuff muscles, combined with the passive exercises done in the first phase to keep on stretching the tissues without overexerting them. Exercises include

pushups The push-up (press-up in British English) is a common calisthenics Physical exercise, exercise beginning from the prone position. By raising and lowering the body using the arms, push-ups exercise the pectoralis major muscle, pectoral muscl ...

and shoulder shrugs, and after a couple of weeks of this, daily activities are gradually added to the patient's routine. This program does not require any sort of medication or surgery and can serve as a good alternative. The rotator cuff and the upper muscles are responsible for many daily tasks that people do in their lives. A proper recovery needs to be maintained and achieved to prevent limiting movement, and can be done through simple movements.

Additional images

File:Shoulder joint.svg, Human shoulder joint, front view File:Shoulder joint back-en.svg, Human shoulder joint, back view File:Gray412.png, Muscles on the dorsum of the scapula, and the triceps brachii File:Gray521.png, The scapular and circumflex arteries (posterior view) File:Gray810.png, Suprascapular and axillary nerves of right side, seen from behind File:Gray818.png, The suprascapular, axillary, and radial nerves

References

{{DEFAULTSORT:Rotator cuff Shoulder Upper limb anatomy de:Oberarm#Rotatorenmanschette