(16) Musculoskeletal Flashcards
Joint structures: Articular
includes:
- the joint capsule
- articular cartilage (composed of a collagen matrix containing charged ions and water, allowing the cartilage to change shape in response to pressure or load, acting as a cushion for underlying bone)
- synovium
- synovial fluid (provides nutrition to the adjacent relatively avascular articular cartilage)
- intra-articular ligaments
- juxta-articular bone
Joint structures: Extra-articular
include:
- periarticular ligaments
- tendons
- bursae
- muscle
- fascia
- bone
- nerve
- overlying skin
Age provides clues to causes of joint pain:
<60 years old consider:
repetitive strain or overuse syndromes like tendinitis or bursitis
crystalline arthritis (gout; crystalline pyrophosphate deposition disease [CPPD]) (males)
rheumatoid arthritis (RA)
psoriatic arthritis and reactive (Reiter) arthritis (in inflammatory bowel disease [IBD])
infectious arthritis from gonorrhea, Lyme disease, or viral or bacterial infections.
Age provides clues to causes of joint pain:
>60 years old consider:
OA gout and pseudogout polymyalgia rheumatica (PMR) osteoporotic fracture septic bacterial arthritis
3 types of joints (w/ extent of movement and example)
- Synoval - freely moveable (knee, shoulder)
- Cartilaginous - slightly moveable (vertebral bodies of the spine)
- Fibrous - immovable (skull structures)
Synovial Joints
h other, and the
joint articulations are freely movable within
the limits of the surrounding ligaments
(Fig. 16-3). The bones are covered by
articular cartilage and separated by a
synovial cavity that cushions joint
movement. A synovial membrane lines the
synovial cavity and secretes a small amount
of viscous lubricating fluid, the synovial
fluid. The membrane is attached at the
margins of the articular cartilage and
pouched or folded to accommodate joint
movement. Surrounding the joint is a
fibrous joint capsule, which is strengthened
by ligaments extending from bone to bone.
Cartilaginous Joints
ex: intervertebral joints, symphysis pubis
slightly movable
Fibrocartilaginous discs separate the bony surfaces. At the center of each disc is the nucleus pulposus, somewhat gelatinous fibrocartilaginous material that serves as a cushion or shock absorber between bony surfaces.
Fibrous Joints
ex: sutures of the skull
intervening layers of fibrous tissue or cartilage hold the bones together
The bones are almost in direct contact, which allows no appreciable movement.
3 type of synovial joints w/ articular shape, movement, and example
- Spheroidal (ball and socket) - convex surface in concave cavity
- wide-ranging flexion, extension, abduction, adduction, rotation, circumduction
ex: shoulder, hip - Hinge - flat, plantar
- motion in one plane; flexion, extension
ex: interphalangeal joints of hand and foot; elbow - Condylar - convex or concave
- movement of 2 articulating surfaces not dissociable
ex: knee, TMJ
Spheroidal Joints.
ball-and-socket configuration—a rounded, convex surface articulating with a concave cuplike cavity, allowing a wide range of rotatory movement, as in the shoulder and hip
Hinge Joints
flat, planar, or slightly curved, allowing only a gliding motion in a single plane, as in flexion and extension of the digits
Condylar Joints.
ex: knee
have articulating surfaces that are
convex or concave
allow flexion, extension, rotation, and motion in the coronal plane
Bursae.
roughly disc-shaped synovial sacs that ease joint action and allow adjacent muscles or muscles and tendons to
glide over each other during movement
lie between the skin and the convex surface of a bone or joint, as in the prepatellar bursa of the knee or in areas where tendons or muscles rub against bone, ligaments, or other tendons or muscles, as in the subacromial bursa of the shoulder
Joint Pain: common/concerning symptoms
● Joint pain: articular or extra-articular, acute or chronic, inflammatory or
noninflammatory, localized or diffuse
● Joint pain: associated constitutional symptoms and systemic manifestations
from other organ systems
● Neck pain
● Low back pain
Tips for Assessing Joint Pain
Ask the patient to “point to the pain.” This may save considerable time
because many patients have trouble pinpointing pain location in words.
● Clarify and record when the pain started and the mechanism of injury, particularly
if there is a history of trauma.
● Determine whether the pain is articular or extra-articular, acute or chronic,
inflammatory or noninflammatory, and localized (monoarticular) or diffuse
(polyarticular).
types of joint pain
- monoarticular - one joint
- polyarticular - several joints (usually 4 or more)
- extra-articular - involving bones, muscles, tissues around joints sun as tendons, bursae, overlying skin
4 cardinal features of joint inflammation
swelling, warmth, and
redness, in addition to pain
acute vs chronic joint pain
Acute joint pain typically lasts up to 6 weeks
chronicpain lasts >12 weeks.
2 tools to establish cervical spine injury
NEXUS
Canadian C-spine Rule
3 categories of low back pain
There are numerous clinical guidelines, but most categorize low back pain into three groups:
nonspecific (>90%)
nerve root entrapment with radiculopathy or spinal stenosis (∼5%)
pain from a specific underlying disease (1% to 2%)
Red Flags for Low Back Pain from
Underlying Systemic Disease
- Age <20 years or >50 years
- History of cancer
- Unexplained weight loss, fever, or decline in general health
- Pain lasting more than 1 month or not responding to treatment
- Pain at night or present at rest
- History of intravenous drug use, addiction, or immunosuppression
- Presence of active infection or human immunodeficiency virus (HIV) infection
- Long-term steroid therapy
- Saddle anesthesia, bladder or bowel incontinence
- Neurologic symptoms or progressive neurologic deficit
Physical Activity Guidelines for Americans
At least 2 hours and 30 minutes a week of moderate-intensity, or 1 hour and 15 minutes a week of vigorous-intensity, aerobic physical activity, or an equivalent combination
● Moderate- or high-intensity muscle-strengthening activity that involves all
major muscle groups on 2 or more days a week
Risk Factors for Osteoporosis
● Postmenopausal status in women
● Age ≥50 years
● Prior fragility fracture
● Low body mass index
● Low dietary calcium
● Vitamin D deficiency
● Tobacco and excessive alcohol use
● Immobilization
● Inadequate physical activity
● Osteoporosis in a first-degree relative, particularly with history of fragility
fracture
● Clinical conditions such as thyrotoxicosis, celiac sprue, IBD, cirrhosis, chronic
renal disease, organ transplantation, diabetes, HIV, hypogonadism, multiple
myeloma, anorexia nervosa, and rheumatologic and autoimmune disorders
● Medications such as oral and high-dose inhaled corticosteroids, anticoagulants
(long-term use), aromatase inhibitors for breast cancer, methotrexate,
selected antiseizure medications, immunosuppressive agents, proton-pump
inhibitors (long-term use), and antigonadal therapy for prostate cancer
osteoporosis screening recommendations
The U.S. Preventive Services Task Force
(USPSTF) gives a grade B recommendation supporting osteoporosis screening
for women age ≥65 years and for younger women whose 10-year fracture risk
equals or exceeds that of an average-risk 65-year-old white woman.34 The USPSTF
finds that evidence about risks and benefits for men is insufficient (I statement)
for recommending routine screening. However, the American College of
Physicians recommends that clinicians periodically assess older men for osteoporosis
risk and measure bone density for those at increased risk who are candidates
for drug therapy.37 Screen your patients for the many risk factors listed on
the preceding page, and proceed to further assessment.
bone strength depends on:
bone quality, bone
density, and overall bone size.
best predictor of hip fracture
DEXA measurement of bone density at the femoral neck
read:
- calcium and vitamin d recommendations
- antiresportive and anabolic agents
- preventing falls
p.640-1
Steps for Examining the Joints
- Inspect for joint symmetry, alignment, bony deformities, and swelling
- Inspect and palpate surrounding tissues for skin changes, nodules, muscle
atrophy, tenderness - Assess range of motion and maneuvers to test joint function and stability
and the integrity of ligaments, tendons, bursae, especially if pain or trauma - Assess any areas of inflammation, especially tenderness, swelling, warmth,
redness
Your examination should be systematic. Include inspection, palpation of bony
structures and related joint and soft tissue structures, assessment of range of
motion, and special maneuvers to test specific movements. Recall that the anatomical
shape of each joint determines its range of motion.
Tips for Successful Examination of the
Musculoskeletal System
● During inspection, look for symmetry of involvement. Is the change in joints
symmetric on both sides of the body, or is the change only in one or two joints?
Note any deformities or malalignment of bones or joints.
● Use inspection and palpation to assess the surrounding tissues, noting skin
changes, subcutaneous nodules, and muscle atrophy. Note any crepitus, an
audible or palpable crunching during movement of tendons or ligaments over
bone or areas of cartilage loss. This may occur in joints without pain but is
more significant when associated with symptoms or signs.
● Test range of motion and maneuvers (described for each joint) to demonstrate
limitations in range of motion or joint instability from excess mobility of
joint ligaments, called ligamentous laxity.
● Finally, test muscle strength to aid in the assessment of joint function (for
these techniques, see Chapter 17, pp. 743–748).
Assessing the Four Signs of Inflammation
● Swelling. Palpable swelling may involve: (1) the synovial membrane, which can
feel boggy or doughy; (2) effusion from excess synovial fluid within the joint
space; or (3) soft tissue structures, such as bursae, tendons, and tendon
sheaths.
● Warmth. Use the backs of your fingers to compare the involved joint with
its unaffected contralateral joint, or with nearby tissues if both joints are
involved.
● Redness. Redness of the overlying skin is the least common sign of inflammation
near the joints and is usually seen in more superficial joints like fingers,
toes, and knees.
● Pain or tenderness. Try to identify the specific anatomic structure that is
tender.
Temporomandibular Joint
Overview, Bony Structures, and Joints. The temporomandibular joint (TMJ) is the most active joint in the body, opening and closing up to 2,000 times a day (Figs. 16-10 and 16-11). It is formed by the fossa and articular tubercle of the temporal bone and the condyle of the mandible. It lies midway between the external acoustic meatus and the zygomatic arch. A fibrocartilaginous disc cushions the action of the condyle of the mandible against the synovial membrane and capsule of the articulating surfaces of the temporal bone. Therefore, it is a condylar synovial joint. Muscle Groups and Additional Structures. The principal muscles opening the mouth are the external pterygoids (Fig. 16-12). Closing the mouth are the muscles innervated by cranial nerve V, the trigeminal nerve— the masseter, the temporalis, and the internal pterygoids
TMJ swelling may appear as:
rounded bulge approximately
0.5 cm anterior to the external auditory meatus.
TMJ: inpection and palpation
Inspect the face for symmetry. Inspect the
TMJ for swelling or redness. Swelling may appear as a rounded bulge approximately
0.5 cm anterior to the external auditory meatus.
To locate and palpate the joint, place
the tips of your index fingers just in
front of the tragus of each ear and ask
the patient to open his or her mouth
(Fig. 16-13). The fingertips should
drop into the joint spaces as the mouth
opens. Check for smooth range of
motion; note any swelling or tenderness.
Snapping or clicking may be felt
or heard in normal people.
Palpate the muscles of mastication:
■ The masseters, externally at the angle of the mandible
■ The temporal muscles, externally during clenching and relaxation of the jaw
■ The pterygoid muscles, internally between the tonsillar pillars at the mandible
TMJ: ROM and maneuvers
The TMJ has glide and hinge motions
in its upper and lower portions, respectively. Grinding or chewing consists primarily
of gliding movements in the upper compartments.
Range of motion is threefold: ask the patient to demonstrate opening and closing,
protrusion and retraction (by jutting the mandible forward), and lateral, or sideto-
side, motion. Normally, as the mouth is opened wide, three fingers can be
inserted between the incisors. During normal protrusion of the jaw, the bottom
teeth can be placed in front of the upper teeth.
Shoulder
The glenohumeral joint of the shoulder is distinguished by wideranging
movement in all directions. This joint is largely uninhibited by bony
structures. The humeral head contacts less than one third of the surface area of
the glenoid fossa and essentially dangles from the scapula, attached by the joint capsule, the intra-articular capsular ligaments, the glenoid labrum, and a
meshwork of muscles and tendons.
The shoulder derives its mobility from a complex interconnected structure of
three joints, three large bones, and three principal muscle groups, often referred
to as the shoulder girdle. These structures are viewed as dynamic stabilizers, which
are capable of movement, or static stabilizers, which are incapable of movement.
■ Dynamic stabilizers: These consist of the SITS muscles of the rotator cuff (Supraspinatus,
Infraspinatus, Teres minor, and Subscapularis), which move the
humerus and compress and stabilize the humeral head within the glenoid
cavity.
■ Static stabilizers: These are the bony structures of the shoulder girdle, the
labrum, the articular capsule, and the glenohumeral ligaments. The labrum
is a fibrocartilaginous ring that surrounds the glenoid and deepens its socket,
providing greater stability to the humeral head. The joint capsule is strengthened
by tendons of the rotator cuff and glenohumeral ligaments, adding to
joint stability
Shoulder: Bony structures
The bony structures of the shoulder include the
humerus, the clavicle, and the scapula (Fig. 16-14). The scapula is anchored to
the axial skeleton only by the sternoclavicular joint and inserting muscles, often
called the scapulothoracic articulation because it is not a true joint.
Identify the manubrium, the sternoclavicular joint, and the clavicle. Also identify
the tip of the acromion, the greater tubercle of the humerus, and the coracoid process,
which are important landmarks of shoulder anatomy
Shoulder: Joints
The glenohumeral joint. In this joint, the head of the humerus articulates with
the shallow glenoid fossa of the scapula. This joint is deeply situated and
normally not palpable. It is a ball-and-socket joint, allowing the arm its wide
arc of movement—flexion, extension, abduction (movement away from the
trunk), adduction (movement toward the trunk), rotation, and circumduction.
■ The sternoclavicular joint. The convex medial end of the clavicle articulates
with the concave hollow in the upper sternum.
■ The acromioclavicular joint. The lateral end of the clavicle articulates with the
acromion process of the scapula.
Shoulder: Muscle Groups
The Scapulohumeral Group. This group extends from the scapula to the
humerus and includes the muscles inserting directly on the humerus, namely the
SITS muscles of the rotator cuff:
■ Supraspinatus—runs above the glenohumeral joint; inserts on the greater
tubercle
■ Infraspinatus and teres minor—cross the glenohumeral joint posteriorly; insert
on the greater tubercle
■ Subscapularis (not illustrated)—originates on the anterior surface of the
scapula and crosses the joint anteriorly; inserts on the lesser tubercle
The scapulohumeral
group rotates the shoulder
laterally (the rotator
cuff ) and depresses and
rotates the head of the
humerus (Fig. 16-15).
See pp. 653–654 for discussion
of rotator cuff
injuries.
The Axioscapular Group. This group attaches the scapula to the trunk
and includes the trapezius, rhomboids, serratus anterior, and levator scapulae
(Fig. 16-15). These muscles rotate the scapula and pull the shoulder posteriorly.
The Axiohumeral Group. This group attaches
the humerus to the trunk and includes the pectoralis
major and minor and the latissimus dorsi (Fig. 16-16).
These muscles rotate the shoulder internally.
The biceps and triceps, which connect the scapula to
the bones of the forearm, are also involved in shoulder
movement, especially forward flexion (biceps) and
extension (triceps).
Shoulder: additional structures
Also important to
shoulder movement are the articular capsule and bursae.
Surrounding the glenohumeral joint is a fibrous
articular capsule formed by the tendon insertions of the
rotator cuff and other capsular structures. The loose fit
of the capsule allows the shoulder bones to separate,
and contributes to the shoulder’s wide range of
movement. The capsule is lined by a synovial membrane
with two outpouchings—the subscapular bursa and the
synovial sheath of the tendon of the long head of the biceps.
To locate the biceps tendon, rotate your arm externally and
find the tendinous cord that runs just medial to the greater
tubercle (Fig. 16-17). Roll it under your fingers. This is the
tendon of the long head of the biceps. It runs in the bicipital
groove between the greater and lesser tubercles.
The principal bursa of the shoulder is the subacromial
bursa, positioned between the acromion and the head of
the humerus and overlying the supraspinatus tendon.
Abduction of the shoulder compresses this bursa. Normally,
the supraspinatus tendon and the subacromial
bursa are not palpable. However, if the bursal surfaces
are inflamed (subacromial bursitis), there may be tenderness
just below the tip of the acromion, pain with
abduction and rotation, and loss of smooth movement
shoulder: insepction
Inspect the shoulder and shoulder girdle anteriorly, then the
scapulae and related muscles posteriorly.
Note any swelling, deformity, muscle atrophy or fasciculations (fine tremors of the
muscles), or abnormal positioning.
Look for swelling of the joint capsule anteriorly or a bulge in the subacromial
bursa under the deltoid muscle. Survey the entire upper extremity for color
change, skin alteration, or unusual bony contours.
shoulder: palpation
Begin by palpating the bony contours and structures of the
shoulder, then palpate any area of pain.
■ Beginning medially, at the sternoclavicular joint, trace the clavicle laterally
with your fingers.
■ From behind, follow the bony spine
of the scapula laterally and upward
until it becomes the acromion (A), the
summit of the shoulder (Fig. 16-18).
Its upper surface is rough and slightly
convex. Identify the anterior tip of the
acromion.
■ With your index finger on top of the acromion, just behind its tip, press
medially with your thumb to find the slightly elevated ridge that marks the
distal end of the clavicle at the acromioclavicular joint (shown by the arrow).
Move your thumb medially and down a short step to the next bony prominence,
the coracoid process (B) of the scapula.
■ With your thumb on the coracoid process, allow your fingers to fall on and
grasp the lateral aspect of the humerus to palpate the greater tubercle (C),
where the SITS muscles insert.
Next, to palpate the biceps tendon in the intertubercular bicipital groove, keep
your thumb on the coracoid process and your fingers on the lateral aspect of
the humerus (Fig. 16-19). Remove
your index finger and place it halfway
between the coracoid process and the
greater tubercle on the anterior surface
of the arm. As you check for tendon
tenderness, rolling the tendon
under the fingertips may be helpful.
You can also rotate the glenohumeral
joint externally, locate the muscle distally
near the elbow, and track the
muscle and its tendon proximally
into the intertubercular groove.
■ To examine the subacromial and subdeltoid bursae and the SITS muscles, first
passively extend the humerus by lifting the elbow posteriorly, which rotates
these structures so that they are anterior to the acromion. Palpate carefully
over the subacromial and subdeltoid bursae (Figs. 16-20 and 16-21). The
underlying palpable SITS muscles are:
Supraspinatus—directly under the acromion
■ Infraspinatus—posterior to supraspinatus
■ Teres minor—posterior and inferior to the supraspinatus
■ Subscapularis—inserts anteriorly and is not palpable
■ The fibrous articular capsule and the broad flat tendons of the rotator cuff are
so closely associated that they must be examined simultaneously. Swelling in
the capsule and synovial membrane is often best detected by looking down
on the shoulder from above. Palpate the capsule and synovial membrane
beneath the anterior and posterior acromion to check for injury or arthritis
Shoulder: ROM
(1) Flexion
Principal Muscles Affecting Movement Anterior deltoid, pectoralis major (clavicular
head), coracobrachialis, biceps brachii
Patient Instructions
“Raise your arms in front of you and overhead.”
(2) Extension Principal Muscles Affecting Movement Latissimus dorsi, teres major, posterior deltoid, triceps brachii (long head) Patient Instructions “Raise your arms behind you.”
(3) Abduction Principal Muscles Affecting Movement Supraspinatus, middle deltoid, serratus anterior (via upward rotation of the scapula) Patient Instructions “Raise your arms out to the side and overhead.”
(4) Adduction Principal Muscles Affecting Movement Pectoralis major, coracobrachialis, latissimus dorsi, teres major, subscapularis Patient Instructions “Cross your arm in front of your body.”
(5) Internal Rotation Principal Muscles Affecting Movement Subscapularis, anterior deltoid, pectoralis major, teres major, latissimus dorsi Patient Instructions “Place one hand behind your back and touch your shoulder blade.” Identify the highest midline spinous process the patient is able to reach
(6) External Rotation Principal Muscles Affecting Movement Infraspinatus, teres minor, posterior deltoid Patient Instructions “Raise your arm to shoulder level; bend your elbow and rotate your forearm toward the ceiling.” OR “Place one hand behind your neck or head as if you are brushing your hair.”
Shoulder: Maneuvers
Acromiocalvicular Joint - Crossover or crossed body
adduction test. Adduct
the patient’s arm
across the chest.
Overall Shoulder Rotation - Apley scratch test. Ask the patient to touch the opposite
scapula using the two motions shown below.
Tests abduction and
external rotation.
Tests adduction and internal
rotation.
Rotator Cuff: Pain Provocation Tests - Painful arc test. Fully adduct the patient’s arm from 0° to 180°. Neer impingement sign. Press on the scapula to prevent scapular motion with one hand, and raise the patient’s arm with the other. This compresses the greater tuberosity of the humerus against the acromion. Hawkins impingement sign. Flex the patient’s shoulder and elbow to 90° with the palm facing down. Then, with one hand on the forearm and one on the arm, rotate the arm internally. This compresses the greater tuberosity against the supraspinatus tendon and coracoacromial ligament.
Strength Tests: External rotation lag test. With the patient’s arm flexed to 90° with palm up, rotate the arm into full external rotation Internal rotation lag test. Ask the patient to place the dorsum of the hand on the low back with the elbow flexed to 90°. Then you lift the hand off the back, which further internally rotates the shoulder. Ask the patient to keep the hand in this position. 90º flexion Drop-arm test. Ask the patient to fully abduct the arm to shoulder level, up to 90°, and lower it slowly. Note that abduction above shoulder level, from 90° to 120°, reflects action of the deltoid muscle.
Composite Tests: External rotation resistance test. Ask the patient to adduct and flex the arm to 90°, with the thumbs turned up. Stabilize the elbow with one hand and apply pressure proximal to the patient’s wrist as the patient presses the wrist outward in external rotation. Empty can test. Elevate the arms to 90° and internally rotate the arms with the thumbs pointing down, as if emptying a can. Ask the patient to resist as you place downward pressure on the arms
