Applied Anatomy Glossary
Lateral movement away from the midline of the trunk, as in raising the arms or legs to the side horizontally.
The rate of change in velocity.
The actual change in relationship between the articular surface of one bone relative to another, characterized as roll, spin, and glide.
Electrical signal transmitted from the brain and spinal cord through axons to the muscle fibers in a particular motor unit providing the stimulus to contract.
Point reached when a muscle becomes shortened to the point that it cannot generate or maintain active tension.
Tension in muscles that is generated via an active contraction of the respective muscle fibers in that muscle.
Movement medially toward the midline of the trunk, as in lowering the arms to the side or legs back to the anatomical position.
Nerves that bring impulses from receptors in the skin, joints, muscles, and other peripheral aspects of the body to the central nervous system.
Aggregate Muscle Action
Muscles working together in groups rather than independently to achieve given joint motions.
A muscle or muscle group that is described as being primarily responsible for a specific joint movement when contracting.
All or None Principle
States that regardless of the number involved, the individual muscle fibers within a given motor unit will fire and contract either maximally or not at all.
amphiarthrodial (amphiarthrosis) joints
Joints that functionally allow only a very slight amount of movement such as synchondrosis (e.g., costochondral joint of the ribs with sternum), syndesmosis (e.g., distal tibiofibular), and symphysis (e.g., symphysis pubis) joints.
Range of muscle fiber length between maximal and minimal lengthening.
The position of reference in which the subject is in the standing position, with feet together and palms of hands facing forward.
Bend or protruding angular projection of a bone such as superior and inferior angle of scapula.
Angle of Pull
The angle between the muscle insertion and the bone on which it inserts.
The change in location of a rotating body.
Motion involving rotation around an axis.
A muscle or muscle group that counteracts or opposes the contraction of another muscle or muscle group.
Anterior Axillary Line
A line parallel to the mid-axillary line which passes through the anterior axillary skin fold.
The axis that has the same directional orientation as the sagittal plane of motion and runs from front to back at a right angle to the frontal plane of motion. Also known as the sagittal or AP axis
Abnormal or excessive rotation forward of a structure, such as femoral ante version.
A tendinous expansion of dense fibrous connective tissue, sheet- or ribbonlike in appearance and resembling a flattened tendon, which serves as a fascia to bind muscles together or as a means of connecting muscle to bone.
The appendages, or the upper and lower extremities, and the shoulder and pelvic girdles.
Joints in which bones glide on each other in limited movement, as in the bones of the wrist (carpal) or the bones of the foot (tarsal).
Motion between the actual articular sur- faces of the bones at a joint.
Joint or articulation between two or more bones.
The skull, vertebral column, ribs, and sternum.
Axis of rotation
The point in a joint about which a bone moves or turns to accomplish joint motion.
An elongated projection that transmits impulses away
from the neuron cell body
The ability to control equilibrium, either static or
Those muscles that, from origin to insertion, cross two different joints, allowing them to perform actions at each joint.
Relating to the right and left sides of the body or of a body structure such as the right and left extremities
The study of mechanics as it relates to the functional and anatomical analysis of biological systems, especially humans
A type of pennate muscle with fibers running obliquely on both sides from a central tendon, such as the rectus femoris and flexor hallucis longus
Border or margin
Edge or boundary line of a bone such as lateral and medial border of scapula.
Group of spinal nerves composed of cervical nerves 5 through 8, along with thoracic nerve 1; supplies motor and sensory function to the upper extrem- ity and most of the scapula.
Spongy, porous bone that lies under cor- tical bone.
Specific planes that divide the body exactly into two halves.
A three-sided arch, concave on the palmar side and formed by the trapezium, trapezoid, capitate, and hamate. It is spanned by the transverse carpal and volar carpal ligaments creating a tunnel.
Carpal tunnel syndrome
A condition characterized by swelling and inflammation with resultant increased pressure in the carpal tunnel, which interferes with nor- mal function of the median nerve, leading to reduced motor and sensory function of its distribution; particu- larly common with repetitive use of the hand and wrist in manual labor and clerical work such as typing and keyboarding.
In the anatomical position, the angle formed by the forearm deviating laterally from the arm, typically 5 to 15 degrees.
Joints joined together by hyaline cartilage or fibrocartilage, allowing very slight movement, such as synchondrosis and symphysis.
Center of Gravity
The point at which all of the body’s mass and weight are equally balanced or equally distributed in all directions.
Center of Rotation
The point or line around which all other points in the body move.
Central Nervous System (CNS)
The cerebral cortex, basal ganglia, cerebellum, brain stem, and spinal cord
Group of spinal nerves composed of cervical nerves 1 through 4; generally responsible for sensory and motor function from the upper part of the shoulders to the back of the head and front of the neck.
Circular movement of a bone at the joint, as in movement of the hip, shoulder, or trunk around a fixed point. Combination of flexion, extension, abduction, and adduction.
Closed Kinetic Chain
When the distal end of an extremity is fixed, preventing movement of any one joint unless predictable movements of the other joints in the extrem- ity occur.
The ratio between the force needed to overcome friction over the force holding the surfaces together.
A protein in the body that forms fibrous con- nective tissues such as ligaments, tendons, cartilage, bone, and skin. Its elongated fibrils provide strength and flexibility to these tissues.
A contraction in which there is a shortening of the muscle that causes motion to occur at the joints it crosses.
Movement pattern allowing the involved biar- ticular muscle to maintain a relatively consistent length because of the same action at both of its joints.
Large, rounded projection that usually articulates with another bone, such as the medial or lateral condyle of the femur.
Type of joint in which the bones permit movement in two planes without rotation, as in the wrist between the radius and the proximal row of the carpal bones or the second, third, fourth, and fifth metacarpo- phalangeal joint
The ability of muscle to contract and develop tension or internal force against resistance when stimulated
In a single muscle fiber contraction, it is the phase following the latent period in which the muscle fiber actually begins shortening; lasts about 40 milliseconds.
Strengthening and conditioning that focuses on the diaphragm, transversus abdominis, lumbar mul- tifidus, and the muscles of the pelvic floor as well as the rectus abdominis, external obliques, internal obliques, and erector spinae.
Runs from side to side through the body and is at a right angle to the sagittal plane of motion. Also known as the frontal or lateral axi
Diaphyseal wall of long bones, formed from hard, dense compact bone.
Harder, more compact bone that forms the outer bony surface of the diaphysis
Movement pattern resulting from opposite actions occurring simultaneously at both joints of a bi-articular muscle resulting in substantial shortening of the biarticular muscle.
The group of 12 pairs of nerves originating from the undersurface of the brain and exiting from the cranial cavity through skull openings.
Motion along a curved line
States that ligaments, muscle, and other soft tissue when placed under appropriate tension will adapt over time by lengthening and conversely when main- tained in a loose or shortened state over a period of time will gradually shorten.
One or more branching projections from the neuron cell body that transmit impulses to the neuron and cell body
Inferior movement of the shoulder girdle, as in returning to the normal position from a shoulder shrug
A defined area of skin supplied by a specific spinal nerve
Relating to, or situated to the right or on the right side of something
Movement by a limb through a diagonal plane away from the midline of the body such as in the hip or glenohumeral joint.
Movement by a limb through a diago- nal plane toward and across the midline of the body such as in the hip or glenohumeral joint.
Diagonal or Oblique Axis
Axis that runs at a right angle to the diagonal plane. As the glenohumeral joint moves from diagonal abduction to diagonal adduction in over- hand throwing, its axis runs perpendicular to the plane through the humeral head.
A combination of more than one plane. Less than parallel or perpendicular to the sagittal, frontal, or transverse plane. Also known as oblique plane.
The long cylindrical portion or shaft of long bones.
Freely movable synovial joints containing a joint capsule and hyaline cartilage and lubricated by synovial fluid.
A change in position or location of an object from its original point of reference.
Farthest from the midline or point or reference; the fingertips are the most distal part of the upper extremity.
When the angle of pull is greater than 90 degrees, the force pulls the bone away from its joint axis, thereby increasing joint distraction forces.
Relating to the back, being or located near, on, or toward the back, posterior part, or upper surface of; also relating to the top of the foot.
Flexion movement of the ankle resulting in the top of foot moving toward the anterior tibia.
An exercise variable usually referring to the number of minutes per exercise bout.
Occurs when all of the applied and inertial forces acting on the moving body are in balance, resulting in movement with unchanging speed or direction.
The study of mechanics involving systems in motion with acceleration.
A contraction in which the muscle lengthens in an attempt to control the motion occurring at the joints that it crosses, characterized by the force of gravity or applied resistance being greater than the con- tractile force.
Force that is applied in a direction not in line with the center of rotation of an object with a fixed axis. In objects without a fixed axis, it is an applied force that is not in line with the object’s center of gravity.
Nerves that carry impulses to the outlying regions of the body from the central nervous system.
The ability of muscle to return to its original length following stretching.
A protein in the body that forms connective tissue. It has a highly elastic quality and will return to its original state after stress, whether compressed or stretched.
A method utilizing either sur- face electrodes or fine wire/needle electrodes to detect the action potentials of muscles and provide an electronic readout of the contraction intensity and duration.
Superior movement of the shoulder girdle, as in shrugging the shoulders.
Type of joint that permits movement in all planes, as in the shoulder (glenohumeral) and hip joints.
Long bones that develop from hyaline cartilage masses after the embryonic stage.
Dense, fibrous membrane covering the inside of the cortex of long bones.
Projection located above a condyle, such as the medial or lateral epicondyle of the humerus.
Thin cartilage plate separating the diaphysis and epiphysis during bony growth; commonly referred to as growth plate.
The end of a long bone, usually enlarged and shaped to join the epiphysis of an adjacent bone, formed from cancellous or trabecular bone.
State of zero acceleration in which there is no change in the speed or direction of the body.
Turning of the sole of the foot outward or later- ally, as in standing with the weight on the inner edge of the foot.
The ability of muscle to be stretched back to its original length following contraction.
Straightening movement resulting in an increase of the angle in a joint by moving bones apart, as when the hand moves away from shoulder during extension of the elbow joint.
Rotary movement around the longitudi- nal axis of a bone away from the midline of the body. Also known as rotation laterally, outward rotation, and lateral rotation.
Muscles that arise or originate outside of (proximal to) the body part on which they act.
Sheet or band of fibrous connective tissue that envel- ops, separates, or binds together parts of the body such as muscles, organs, and other soft tissue structures of the body.
Joints joined together by connective tis- sue fibers and generally immovable, such as gomphosis, sutures, and syndesmosis.
Relating to the fibular (lateral) side of the lower extremity.
A lever in which the axis (fulcrum) is between the force and the resistance, as in the extension of the elbow joint.
A type of parallel muscle that is usually thin and broad, with fibers originating from broad, fibrous, sheetlike aponeuroses such as the rectus abdominus and external oblique.
Movement of the bones toward each other at a joint by decreasing the angle, as in moving the hand toward the shoulder during elbow flexion.
Phase that begins immediately after the climax of the movement phase, in order to bring about negative acceleration of the involved limb or body segment; often referred to as the deceleration phase. The velocity of the body segment progressively decreases, usually over a wide range of motion.
Rounded hole or opening in bone, such as the foramen magnum in the base of the skull.
The product of mass times acceleration.
The perpendicular distance between the loca- tion of force application and the axis. The shortest dis- tance from the axis of rotation to the line of action of the force. Also known as the moment arm or torque arm.
Occurs when two or more forces are pulling in different directions on an object, causing the object to rotate about its axis.
Amount of force usually expressed in newtons.
Hollow, depressed, or flattened surface of bone, such as the supraspinous fossa or iliac fossa.
Very small pit or depression in bone, such as the fovea capitis of the femur.
An exercise variable usually referring to the number of times exercise is conducted per week.
Force that results from the resistance between the surfaces of two objects moving upon one another.
Plane that bisects the body laterally from side to side, dividing it into front and back halves. Also known as the lateral or coronal plane.
Reference position essentially the same as the anatomical position, except that the arms are at the sides and the palms are facing the body.
A type of parallel muscle with fibers shaped together like a spindle with a central belly that tapers to tendons on each end, such as the brachialis and the biceps brachii.
The central, fleshy, contractile portion of the muscle that generally increases in diameter as the muscle contracts.
Type of joint that permits a wide range of movement in only one plane, as in the elbow, ankle, and knee joints.
Golgi Tendon Organ
A proprioceptor, sensitive to both muscle tension and active contraction, found in the tendon close to the muscle tendon junction.
A type of immovable articulation, as of a tooth inserted into its bony socket.
Instrument used to measure joint angles or compare the changes in joint angles
Measuring the available range of motion in a joint or the angles created by the bones of a joint.
Ground Reaction Force
The force of the surface reacting to the force placed on it, as in the reaction force between the body and the ground when running across a surface.
A common name given to the group of poste- rior thigh muscles: biceps femoris, semitendinosus, and semimembranosus.
Prominent, rounded projection of the proximal end of a bone, usually articulating, such as the humeral or femoral head.
First portion of the walking or running stance phase characterized by landing on the heel with the foot in supination and the leg in external rotation.
Movement of the humerus in the horizontal plane away from the midline of the body.
Movement of the humerus in the horizontal plane toward the midline of the body.
Articular cartilage; covers the end of bones at diarthrodial joints to provide a cushioning effect and reduce friction during movement.
Extension beyond the normal range of extension.
Occurs when the tendons of the rotator cuff muscles, particularly the supraspinatus and infraspinatus, become irritated and inflamed as they pass through the subacromial space between the acromion process of the scapula and the head of the humerus, typi- cally resulting in pain, weakness, and loss of movement.
The product of force and time.
Resistance to action or change; resistance to acceleration or deceleration. Inertia is the tendency for the current state of motion to be maintained, regardless of whether the body segment is moving at a particular velocity or is motionless.
The supplying of a muscle, organ, or body part with nerves.
The distal attachment or point of attachment of a muscle farthest from the midline or center of the body, generally considered the most movable part.
Instantaneous Center of Rotation
The center of rotation at a specific instant in time during movement.
An exercise variable usually referring to a certain percentage of the absolute maximum that a person can sustain.
Rotary movement around the longitudi- nal axis of a bone toward the midline of the body. Also known as rotation medially, inward rotation, and medial rotation.
Central or connecting neurons that conduct impulses from sensory neurons to motor neurons.
Muscles that are entirely contained within a specified body part; usually refers to the small, deep muscles found in the foot and hand.
Turning of the sole of the foot inward or medially, as in standing with the weight on the outer edge of the foot.
The property of muscle being sensitive or responsive to chemical, electrical, or mechanical stimuli.
Type of dynamic exercise usually using concen- tric and/or eccentric muscle contractions in which the speed (or velocity) of movement is constant and mus- cular contraction (usually maximal contraction) occurs throughout the movement.
A type of contraction with little or no shortening of the muscle resulting in no appreciable change in the joint angle.
Contraction occurring in which there is either shortening or lengthening in the muscle under tension; also known as a dynamic contraction, and classified as being either concentric or eccentric.
The description of motion, including consid- eration of time, displacement, velocity, acceleration, and space factors of a system’s motion.
The science of movement, which includes anatomical (structural) and biomechanical (mechanical) aspects of movement.
The awareness of the position and movement of the body in space; sense that provides awareness of bodily position, weight, or movement of the muscles, ten- dons, and joints.
The amount of friction occurring between two objects that are sliding upon one another.
The study of forces associated with the motion of a body.
Krause's end bulbs
A proprioceptor sensitive to touch and thermal changes found in the skin, subcutaneous tis- sue, lip and eyelid mucosa, and external genitals.
Increased curving of the spine outward or back- ward in the sagittal plane.
In a single muscle fiber contraction, it is the brief period of a few milliseconds following the stimulus before the contraction phase begins.
Axis that has the same directional orienta- tion as the frontal plane of motion and runs from side to side at a right angle to the sagittal plane of motion. Also known as the frontal or coronal axis.
A common problem quite frequently associated with gripping and lifting activities that usually involves the extensor digitorum muscle near its origin on the lateral epicondyle; commonly known as tennis elbow.
Movement of the head and/or trunk later- ally away from the midline; abduction of spine.
Law of Acceleration
A change in the acceleration of a body occurs in the same direction as the force that caused it and is directly proportional to the force causing it and inversely proportional to the mass of the body.
Law of Reaction
For every action there is an opposite and equal reaction.
A rigid bar (bone) that moves about an axis.
A type of tough connective tissue that attaches bone to bone to provide static stability to joints.
The distance that a system moves in a straight line.
Motion along a line; also referred to as translatory motion.
Increased curving of the spine inward or forward in the sagittal plane.
A reduction of its normal lordotic curve, resulting in a flat-back appearance.
Group of spinal nerves composed of L1 through L4 and some fibers from T12, generally respon- sible for motor and sensory function of the lower abdo- men and the anterior and medial portions of the lower extremity.
The amount of matter in a body
A stimulus strong enough to produce action potentials in all of the motor units of a particular muscle
The advantage gained through the use of machines to increase or multiply the applied force in performing a task; enables a relatively small force to be applied to move a much greater resistance; determined by dividing the load by the effort.
The study of physical actions of forces; can be subdivided into statics and dynamics
An elbow problem associated with the medial wrist flexor and pronator group near their ori- gin on the medial epicondyle; frequently referred to as golfer’s elbow.
Marrow cavity between the walls of the diaphysis, containing yellow or fatty marrow.
A proprioceptor sensitive to fine touch and vibration found in the skin.
A line running vertically down the sur- face of the body passing through the apex of the axilla (armpit).
A line running vertically down the sur- face of the body passing through the midpoint of the clavicle.
Cardinal plane that bisects the body from front to back, dividing it into right and left symmetrical halves.
Middle portion of the walking or running stance phase characterized by pronation and internal rotation of the foot and leg; may be divided into loading response, midstance, and terminal stan
A line running vertically down the surface of the body passing through the middle of the sternum.
The quality of motion, which is equal to mass times velocity.
Neurons that transmit impulses away from the brain and spinal cord to muscle and glandular tissue.
Consists of a single motor neuron and all of the muscle fibers it innervates.
The action part of a skill, sometimes known as the acceleration, action, motion, or contact phase. Phase in which the summation of force is gener- ated directly to the ball, sport object, or opponent, and is usually characterized by near-maximal concentric activity in the involved muscles.
Those muscles that, from origin to insertion, cross three or more different joints, allowing them to perform actions at each joint.
A type of pennate muscle that has several tendons with fibers running diagonally between them, such as the deltoid.
A proprioceptor sensitive to stretch and the rate of stretch that is concentrated primarily in the muscle belly between the fibers.
The reflexive contraction that occurs as a result of the motor neurons of a muscle being activated from the CNS secondarily to a rapid stretch occurring in the same muscle; the knee jerk or patella tendon reflex is an example.
A muscle or group of muscles supplied by a spe- cific spinal nerve.
Connection between the ner- vous system and the muscular system via synapses between efferent nerve fibers and muscle fibers.
Nerve cell that is the basic functional unit of the nervous system responsible for generating and transmit- ting impulses.
Neuron Cell Body
Portion of a neuron containing the nucleus but not including the axon and dendrites.
Muscles that counteract or neutralize the action of other muscles to prevent undesirable move- ments; referred to as neutralizing, they contract to resist specific actions of other muscles.
Compo- nent (either stabilizing or dislocating) of muscular force acting parallel to the long axis of the bone (lever).
Open Kinetic Chain
When the distal end of an extremity is not fixed to any surface, allowing any one joint in the extremity to move or function separately without neces- sitating movement of other joints in the extremity.
Diagonal movement of the thumb across the palmar surface of the hand to make contact with the hand and/or fingers.
The proximal attachment or point of attachment of a muscle closest to the midline or center of the body, gen- erally considered the least movable part.
Specialized cells that form new bone.
Specialized cells that resorb new bone.
Motion of the bones relative to
the three cardinal planes, resulting from physiological
A proprioceptor sensitive to pressure and vibration found in the subcutaneous, submucosa, subserous tissues around joints, external genitals, and mammary glands.
Flexion movement of the wrist in the sagittal plane with the volar or anterior side of the hand moving toward the anterior side of the forearm.
Using the sense of touch to feel or examine a
muscle or other tissue.
Muscles that have their fibers arranged parallel to the length of the muscle, such as flat, fusiform, strap, radiate, or sphincter muscles.
Planes parallel to the midsagittal plane.
State reached when an opposing muscle becomes stretched to the point where it can no longer lengthen and allow movement.
Tension in muscles that is due to externally applied forces and is developed as a muscle is stretched beyond its normal resting length.
Muscles that have their fibers arranged obliquely to their tendons in a manner similar to a feather, such as unipennate, bipennate, and multi-pennate muscles.
The intentional variance of overload through a prescriptive reduction or increase in a training program to bring about optimal gains in physical performance.
The dense, fibrous membrane covering the outer surface of the diaphysis.
Peripheral Nervous System
Portion of the nervous system containing the sensory and motor divisions of all the nerves throughout the body except those found in the central nervous system.
Normal movements of joints such as flexion, extension, abduction, adduction, and rotation, accomplished by bones moving through planes of motion about an axis of rotation at the joint.
Plane of Motion
An imaginary two-dimensional surface through which a limb or body segment is moved.
Relating to the sole or undersurface of the foot.
Extension movement of the ankle, resulting in the foot and/or toes moving away from the body.
An anatomical variant of synovial tissue folds that may be irritated or inflamed with injuries or overuse of the knee.
Posterior Axillary Line
A line parallel to the mid-axillary line which passes through the posterior axillary skinfold.
Skill analysis phase, often referred to as the cocking or wind-up phase, used to lengthen the appropriate muscles so that they will be in position to generate more force and momentum as they concentrically contract in the next phase.
Muscles that contribute significantly to causing a specific joint movement when contracting concentrically.
Internally rotating the radius so that it lies diag- onally across the ulna, resulting in the palm-down posi- tion of the forearm; term also refers to a combination of ankle dorsiflexion, subtalar eversion, and forefoot abduc- tion (toe-out).
Feedback relative to the tension, length, and contraction state of muscle, the position of the body and limbs, and movements of the joints provided by internal receptors located in the skin, joints, muscles, and tendons.
Forward movement of the shoulder girdle away from the spine; abduction of the scapula.
Nearest to the midline or point of reference; the forearm is proximal to the hand.
Q Angle (Quadricep Femoris)
The angle at the patella formed by the intersection of the line of pull of quadriceps with the line of pull of the patella tendon.
A common name given to the four muscles of the anterior aspect of the thigh: rectus femoris, vastus medialis, vastus intermedius, and vastus lateralis.
Relating to the radial (lateral) side of the forearm or hand.
Radial Deviation (Radial Flexion)
Abduction movement at the wrist of the thumb side of the hand toward the forearm.
A type of parallel muscle with a combined arrangement of flat and fusiform muscle in that they origi- nate on broad aponeuroses and converge onto a tendon such as the pectoralis major or trapezius. Also described sometimes as being triangular, fan-shaped, or convergent.
Range of Motion
The specific amount of move- ment possible in a joint.
Activation of the motor units of the agonists, causing a reciprocal neural inhibition of the motor units of the antagonists, which allows them to sub- sequently lengthen under less tension. Also referred to as reciprocal innervation.
Skill analysis phase used after follow- through to regain balance and positioning to be ready for the next sport demand.
Motion along a straight line.
Bending backward, as in knee hyperextension.
Return of the spinal column to the anatomic position from lateral flexion; spine adduction.
In a single muscle fiber contraction, it is the phase following the contraction phase in which the muscle fiber begins relaxing; lasts about 50 milliseconds.
Diagonal movement of the thumb as it returns to the anatomical position from opposition with the hand and/or fingers.
Component of the lever that is typically being attempted to be moved, usually referred to as load, weight, or mass.
The distance between the axis and the point of resistance application.
Fascial tissue that retains tendons close to the body in certain places such as around joints like the wrist and ankle.
Backward movement of the shoulder girdle toward the spine; adduction of the scapula.
Abnormal or excessive rotation backward of a structure, such as femoral retroversion.
The resistance to an object rolling across a surface, such as a ball rolling across a court or a tire roll- ing across the ground.
Movement around the axis of a bone, such as the turning inward, outward, downward, or upward of a bone.
Component of muscular force acting perpendicular to the long axis of the bone (lever).
Group of muscles intrinsic to the glenohu- meral joint, consisting of the subscapularis, supraspi- natus, infraspinatus, and teres minor, that is critical in maintaining dynamic stability of the joint.
A proprioceptor sensitive to touch and pressure found in the skin, subcutaneous tissue of fingers, and collagenous fibers of the joint capsule.
Group of spinal nerves composed of L4, L5, and S1 through S4, generally responsible for motor and sensory function of the lower back, pelvis, perineum, posterior surface of the thigh and leg, and dorsal and plantar surfaces of the foot.
Plane that bisects the body from front to back, dividing it into right and left symmetrical halves. Also known as the anteroposterior, or AP plane.
Mathematical quantities are described by a magni- tude (or numerical value) alone such as speed, length, area, volume, mass, time, density, temperature, pressure, energy, work, and power.
Movement of the humerus away from the body in the scapula plane. Glenohumeral abduction in a plane halfway between the sagittal and frontal plane.
A line running vertically down the posterior surface of the body
passing through inferior angle of the scapula.
Lateral curving of the spine.
A lever in which the resistance is between the axis (fulcrum) and the force (effort), as in plantarflexing the foot to raise up on the toes.
Neurons that transmit impulses to the
spinal cord and brain from all parts of the body.
Slang term frequently used to describe an often chronic condition in which the tibialis posterior, tib- ialis anterior, and extensor digitorum longus muscles are inflamed, typically a tendinitis of one or more of these structures.
Relating to, or situated to the left or on the left side of something.
Cavity or hollow space within a bone, such as the frontal or maxillary sinus.
Afferent nerves, which are under conscious control and carry impulses to skeletal muscles.
How fast an object is moving, or the distance an object travels in a specific amount of time.
A type of parallel muscle that is a tech- nically endless strap muscle with fibers arranged to sur- round and close openings upon contraction, such as the orbicularis oris. Also referred to as circular muscles.
A type of accessory motion characterized by a sin- gle point on one articular surface rotating clockwise or counterclockwise about a single point on another articular surface.
The group of 31 pairs of nerves that origi- nate from the spinal cord and exit the spinal column on each side through openings between the vertebrae. They run directly to specific anatomical locations, form different plexuses, and eventually become peripheral nerve branches.
The resistance to a change in the body’s accel- eration; the resistance to a disturbance of the body’s equilibrium.
Muscles that surround the joint or body part and contract to fixate or stabilize the area to enable another limb or body segment to exert force and move; known as fixators, they are essential in establishing a relatively firm base for the more distal joints to work from when carry- ing out movements.
When the angle of pull is less than 90 degrees, the force pulls the bone toward its joint axis, thereby increasing joint compression forces.
The body at complete rest or motionless.
The amount of friction between two objects that have not yet begun to move.
An active stretch via an eccentric contraction of a muscle followed by an immediate con- centric contraction of the same muscle.
Stimuli that are strong enough to pro- duce action potentials in multiple motor units, but not all motor units of a particular muscle.
Stimulus not strong enough to cause an action potential and therefore does not result in a contraction.
When successive stimuli are provided before the relaxation phase of the first twitch is complete allow- ing the subsequent twitches to combine with the first to produce a sustained contraction generating greater ten- sion than a single contraction would produce on its own.
Externally rotating the radius to where it lies parallel to the ulna, resulting in the palm-up position of the forearm; term is also used in referring to the com- bined movements of inversion, adduction, and internal rotation of the foot and ankle.
Line of union between bones, such as the sagittal suture between the parietal bones of the skull.
Type of joint held together by strong ligamentous structures that allow minimal movement between the bones, such as the coracoclavicular joint and the inferior tibiofibular joint.
Muscles that assist in the action of the agonists but are not primarily responsible for the action; known as guiding muscles, they assist in refined movement and rule out undesired motions.
Muscles that have an action common to each other, but also have actions antagonistic to each other; they help another muscle move the joint in the desired manner and simultaneously prevent undesired actions.
Muscles that contract to prevent an undesired joint action of the agonist and have no direct effect on the agonist action.
Freely movable diarthrodial joints contain- ing a joint capsule and hyaline cartilage and lubricated by synovial fluid.
Horizontal indentations that tran- sect the rectus abdominus at three or more locations, giv- ing the muscle its segmented appearance.
Fibrous connective tissue, often cordlike in appear- ance, that connects muscles to bones and other structures.
When stimuli are provided at a frequency high enough that no relaxation can occur between muscle contractions.
A lever in which the force (effort) is between the axis (fulcrum) and the resistance, as in flex- ion of the elbow joint.
When the stimulus is strong enough to produce an action potential in a single motor unit axon and all of the muscle fibers in the motor unit contract.
Relating to the tibial (medial) side of the lower extremity.
Last portion of the walking or running stance phase characterized by
the foot returning to supination and the
leg returning to external rotation.
Moment of force; the turning effect of an eccentric
Plane that divides the body horizontally into superior and inferior halves; also known as the axial or horizontal plane.
A staircase effect phenomenon of muscle contraction that occurs when rested muscle is stimulated repeatedly with a maximal stimulus at a frequency that allows complete relaxation between stimuli, the second contraction produces a slightly greater tension than the first, and the third contraction produces greater tension than the second.
The gastrocnemius and soleus together; tri- ceps referring to the heads of the medial and lateral gas- trocnemius and the soleus; surae referring to the calf.
A very large bony projection, such as the greater or lesser trochanter of the femur.
Type of joint with a rotational movement around a long axis, as in rotation of the radius at the radioulnar joint.
A small, rounded, bony projection, such as the greater and lesser tubercles of the humerus.
A large, rounded, or roughened, bony projec- tion, such as the radial tuberosity or tibial tuberosity
Relating to the ulnar (medial) side of the forearm or hand.
Ulnar Deviation (Ulnar Flexion)
Adduction movement at the wrist of the little finger side of the hand toward the forearm.
Those muscles that, from origin to insertion, cross only one joint, allowing them to perform actions only on the single joint that they cross.
A type of pennate muscle with fibers that run obliquely from a tendon on one side only, such as the biceps femoris, extensor digitorum longus, and tibialis posterior.
Outward angulation of the distal segment of a bone or joint, as in knock-knee
Inward angulation of the distal segment of a bone or joint, as in bowlegs.
Mathematical quantity described by both a magni- tude and a direction such as velocity, acceleration, direc- tion, displacement, force, drag, momentum, lift, weight, and thrust.
Includes the direction and describes the rate of displacement.
Relating to the belly or abdomen, on or toward the front, anterior part of.
A line running vertically down through the spinous processes of the spine.
Axis that runs straight down through the top of the head and spinal column and is at a right angle to the transverse plane of motion. Also known as the longi- tudinal or long axis.
Nerves that carry impulses to the heart, smooth muscles, and glands; referred to as the autonomic nervous system.
Relating to the palm of the hand or the sole of the foot.
States that bone in a healthy individual will adapt to the loads it is placed under. When a particu- lar bone is subjected to increased loading, the bone will remodel itself over time to become stronger to resist that particular type of loading.