acromioclavicular joint (AC)
the joint found in the shoulder that connects the clavicle to the acromion process of the scapula
anisotropy
the quality of comprising varying values of a given property when measured in different directions
aponeurosis
bandlike flat tendons connecting muscle to bone
Baker’s cyst
synovial fluid collection in the posterior fossa
bursa
a saclike structure containing thick fluid that surrounds areas subject to friction, such as the interface between bone and tendon
cartilage interface sign
echogenic line on the anterior surface of the cartilage surrounding the humeral head
clapper-in-the-bell sign
hypoechoic hematoma found at the end of a completely retracted muscle fragment
comet tail artifact (ring-down)
posterior linear equidistant artifact created when sound reverberates between two strong reflectors, such as air bubbles, metal, and glass
dorsiflexion
upward movement of the hand or foot
epineurium
the covering of a nerve that consists of connective tissue
fasciculi
term describing a small bundle of muscles, nerves, and tendons
Guyon’s canal or tunnel
a fibrous tunnel that contains the ulnar artery and vein, ulnar nerve, and some fatty tissue
ligament
fibrous band of tissue connecting bone or cartilage to bone that aids in stabilizing a joint
muscle
a type of tissue consisting of contractile cells or fibers that affects movement of an organ or part of the body
myelin
substance forming the sheath of Schwann cells
naked tuberosity sign
the deltoid muscle is on the humeral head; seen with a full-thickness tear of the rotator cuff
nerve
conduit for impulses sent to and from the muscles and the central nervous system (CNS)
pennate
feather-like pattern of muscle growth
perineurium
the connective tissue that surrounds muscle
Phalen’s sign (Phalen’s test, Phalen’s maneuver, or Phalen’s position)
an increase in wrist compression due to hyperflexion of the wrist for 60 seconds; this test is done with the patient holding the forearms upright and pressing the ventral sides of the hands together
plantar flexion
pointing of the toes toward the plantar surface of the foot
refractile shadowing (edge artifact)
bending of the sound beam at the edge of a circular structure, resulting in the absence of posterior echoes
seroma
accumulation of serous fluid within tissue
synovial sheath
membrane surrounding a joint, tendon, or bursa that secretes a viscous fluid called synovia
tendinitis (tendinopathy, tendinosis, or tenosynovitis)
inflammation of a tendon
tendon
fibrous tissue connecting muscle to bone
Thompson’s test
a test used to evaluate the integrity of the Achilles tendon that involves plantar flexion with squeezing of the calf
Tinel’s sign (Hoffmann-Tinel sign, Tinel’s symptom, or Tinel-Hoffmann sign)
pins-and-needles–type tingling felt distal to a percussion site. Sensation can be abnormal or can be a normal occurrence (i.e., hitting the elbow creates a tingling in the distal arm)
volar
the anterior portion of the body when in anatomic position