Chapter 7 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
biomechanics uses scientific principles of physics to study how the body creates movement at the joints, especially in the context of exercise and sport
Kinesiology
Study of movement as it relates to anatomy and physiology.
Anatomic position
when the body is in a standing posture, with the arms hanging down
Medial
Relatively closer to the midline of the body
Lateral
Relatively farther away from the midline or
toward the outside of the body
Proximal
Positioned nearest to the center of the body
or other identified reference point
The wrist is more proximal to the elbow than
the fingers.
Distal
Positioned farthest from the center of the
body or other identified reference point
The ankle is more distal to the hip than the
knee.
Inferior
Positioned below an identified reference
point
The soleus (calf muscle) is inferior to the
hamstring complex.
Superior
Positioned above an identified reference point
The pelvis is superior to the tibia (shin bone).
Sagittal plane
An imaginary bisector that divides the body into left and right halves.
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
The bottom of foot faces outward.
Inversion
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.
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.
Gait
Biomechanical motion of the lower extremities during walking, running, and sprinting.
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.
Eccentric muscle action
A muscle action that occurs when a muscle develops tension while lengthening.
Isotonic
concentric and eccentric muscle actions.
Isometric
Muscle tension is created without a change in muscle length and no visible movement of the joint.
Isokinetic
The speed of movement is fixed, and resistance varies with the force exerted.
Motor unit
A motor neuron and all of the muscle fibers that it innervates.
Concentric muscle action
exerting force greater than the resistive force, resulting in a shortening of the muscle.
Agonists
The muscles most responsible for generating the primary forces for a particular movement
muscle action spectrum
Because practically every exercise consists of an eccentric, isometric, and concentric muscle action to complete one repetition, the movement through those muscle actions is referred to as the muscle action spectrum.
Synergists
Muscles that assist agonists to produce a movement.
feed-forward activation.
certain muscles have the ability to stabilize a joint by contracting automatically in anticipation of movement
closed-chain movements
a person’s hands or feet, are fixed and remain in contact with a stationary surface
open-chain movements
the distal segments (hands and feet) are not fixed, and they are free to move in space.
Force
An influence applied by one object to another, which results in an acceleration or deceleration of the second object.
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
If a muscle’s resting length is either too long or too short on one side of a joint, however, it has an altered length-tension relationship.
reciprocal inhibition.
The scientific term that describes the nervous system’s role in the contract-relax relationship between agonists and antagonists is called reciprocal inhibition. When the agonist for a movement receives a signal (a motor neuron impulse) to contract, the central nervous system also sends a signal that inhibits the antagonist’s activation signals at the same time, causing it to relax.
Altered reciprocal inhibition
Altered reciprocal inhibition is when an agonist muscle chronically receives an activation signal causing the functional antagonist to chronically receive the inhibitory signal.
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
The stretch-shortening cycle is a term used to describe a loaded eccentric muscle action that prepares muscles and tendons for a rapid concentric contraction.
Series elastic component
Springlike noncontractile component of muscle and tendon that stores elastic energy.
The stored energy is a result of the series elastic component of muscle and tendon (mostly tendon)
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.
Integrated performance paradigm
To move with efficiency, forces must be dampened (eccentrically), stabilized (isometrically), and then accelerated (concentrically).
Tendon
A fibrous connective tissue that connects muscle to bone.
Force-couple relationship
Because muscles are recruited as groups, many muscles will transmit force onto their respective bones, creating movement at the joints. This synergistic action of multiple muscles to produce movement around a joint is known as a force-couple relationship.
Joint support systems
Muscular stabilization systems located in joints distal of the spine.
The deep longitudinal subsystem (DLS)
(DLS) includes muscles of the lower leg, hamstrings, and lower back region
The posterior oblique subsystem (POS)
(POS) is made up of the latissimus dorsi, thoracolumbar fascia (connective tissue of the low-back), and contralateral gluteus maximus.
The anterior oblique subsystem (AOS)
(AOS) is similar to the POS, just on the anterior side of the body. The muscles include the obliques, the adductor (inner) thigh muscles, and the hip external rotators. The obliques and contralateral (opposite) adductors are the most common visualization of this subsystem because of the X pattern made across the front of the body
Rotary Motion
Movement of the bones around the joints.
Motor behavior
Motor behavior is the HMS response to internal and external environmental stimuli
