CH 7 Human Movement Systems Flashcards
Human movement system (HMS)
The collective components and structures that work together to move the body: muscular, skeletal, and nervous systems.
Kinetic chain
A concept that describes the human body as a chain of interdependent links that work together to perform movement.
Regional interdependence model
The concept describing the integrated functioning of multiple body systems or regions of the body.
Biomechanics
The science concerned with the internal and external forces acting on the human body and the effects produced by these forces.
Anatomic position
The position with the body erect, the arms at the sides, and the palms forward. It is the position of reference for anatomic nomenclature
Osteokinematics
Movement of a limb that is visible.
Arthrokinematics
The description of joint surface movement; consists of three major types: roll, slide, and spin.
Dorsiflexion
Flexion occurring at the ankle.
Plantar flexion
Extension occurring at the ankle. Pointing the foot downwards.
Frontal Plane
An imaginary bisector that divides the body into front and back halves. Movement in the frontal plane includes abduction, adduction, and side-to-side motions.
Abduction
A movement in the frontal plane away from the midline of the body.
Adduction
Movement in the frontal plane back toward the midline of the body.
Lateral flexion
Bending of the spine from side to side.
Eversion
A movement in which the inferior calcaneus (heel bone) moves laterally. The bottom of foot faces outward.
Inversion
A movement in which the inferior calcaneus (heel bone) moves medially. Bottom of foot faces inward.
Transverse plane
An imaginary bisector that divides the body into top and bottom halves.
Internal rotation
Rotation of a body segment toward the middle of the body
External rotation
Rotation of a body segment away from the middle of the body.
Horizontal abduction
Movement of the arm or thigh in the transverse plane from an anterior position to a lateral position.
Horizontal adduction
Movement of the arm or thigh in the transverse plane from a lateral position to an anterior position.
Radioulnar pronation
Inward rotation of the forearm from a palm-up position to a palm-down position.
Radioulnar supination
Outward rotation of the forearm from a palm-down position to a palm-up position
Pronation of the foot
Multiplanar movement of the foot and ankle complex consisting of eversion, dorsiflexion, and ankle abduction; associated with force reduction.
Supination of the foot
Multiplanar movement of the foot and ankle complex consisting of inversion, plantar flexion, and ankle adduction; associated with force production.
Scapular retraction
Adduction of scapulae; shoulder blades move toward the midline.
Scapular protraction
Abduction of scapulae; shoulder blades move away from the midline.
Scapular depression
The downward (inferior) motion of the scapulae.
Scapular elevation
Upward (superior) motion of the scapulae.
Elasticity
The ability of soft tissues to return to resting length after being stretched.
Ligament
A fibrous connective tissue that connects bone to bone.
Flexibility
The normal extensibility of soft tissues that allows for full range of motion of a joint.
Hypermobility
A state where a lack of neuromuscular support leads to a joint having more range of motion than it should, greatly increasing the risk of injury at that joint.
Hypomobility
When range of motion at a joint is limited.
Eccentric muscle action
A muscle action that occurs when a muscle develops tension while lengthening.
Motor unit
A motor neuron and all of the muscle fibers that it innervates.
Concentric muscle action
A muscle action that occurs when a muscle is exerting force greater than the resistive force, resulting in a shortening of the muscle.
Isometric muscle action
When a muscle is exerting force equal to the force being placed on it leading to no visible change in the muscle length.
Core
The structures that make up the lumbo-pelvic-hip complex (LPHC), including the lumbar spine, pelvic girdle, abdomen, and hip joint.
Muscle action spectrum
The full range of eccentric, isometric, and concentric muscle contractions required to perform a movement.
Agonists
The primary muscles providing force for a movement..
Synergists
Muscles that assist agonists to produce a movement.
Stabilizers
Muscles that contract isometrically to stabilize the trunk and joints as the body moves.
Feed-forward activation
When a muscle is automatically activated in anticipation of a movement.
Antagonist
Muscles on the opposite side of a joint that are in direct opposition of agonist muscles
Force
An influence applied by one object to another, which results in an acceleration or deceleration of the second object.
Length-tension relationship
The resting length of a muscle and the tension the muscle can produce at this resting length.
Resting length
The length of a muscle when it is not actively contracting or being stretched.
Actin
The thin, stringlike, myofilament that acts along with myosin to produce muscular contraction.
Myosin
The thick myofilament that acts along with actin to produce muscular contraction.
Sarcomere
The structural unit of a myofibril composed of actin and myosin filaments between two Z-lines.
Muscle balance
When all muscles surrounding a joint have optimal length-tension relationships, allowing the joint to rest in a neutral position.
Altered length-tension relationship
When a muscle’s resting length is too short or too long, reducing the amount of force it can produce.
Reciprocal inhibition
When an agonist receives a signal to contract, its functional antagonist also receives an inhibitory signal allowing it to lengthen.
Altered reciprocal inhibition
Occurs when an overactive agonist muscle decreases the neural drive to its functional antagonist.
Muscle imbalance
When muscles on each side of a joint have altered length-tension relationships.
Neutral position
The optimal resting position of a joint that allows it to function efficiently through its entire normal range of motion
Stretch-shortening cycle
Loading of a muscle eccentrically to prepare it for a rapid concentric contraction.
Series elastic component
Springlike noncontractile component of muscle and tendon that stores elastic energy.
Amortization phase
The transition from eccentric loading to concentric unloading during the stretch-shortening cycle.
Stretch Reflex
Neurological signal from the muscle spindle that causes a muscle to contract to prevent excessive lengthening.
Force-couple relationship
The synergistic action of multiple muscles working together to produce movement around a joint.
Rotary motion
Movement of the bones around the joints.
Integrated performance paradigm
To move with efficiency, forces must be dampened (eccentrically), stabilized (isometrically), and then accelerated (concentrically).
