Chapter 5 Flashcards
Human Movement System (HMS)
Three main systems within the human body, the nervous system (central and
peripheral), the skeletal (articular) system, and the muscular system. These collective
components and structures represent the human movement system (HMS)
Biomechanics
The science
concerned with the internal and
external forces acting on the
human body and the effects
produced by these forces.
Anatomic Locations: Superior
Refers to a position above a reference point.
The femur (thigh bone) is superior to the tibia (shin bone). The pectoralis major (chest muscle) is superior to the rectus abdominis (abdominal muscle).
Anatomic Locations: Inferior
Refers to a position below a reference point.
The calcaneus (heel bone) is inferior
to the patella (knee bone). The soleus (calf muscle) is inferior to the hamstring
complex.
Anatomaic Locations: Proximal
Refers to a position nearest the center of the body or point of reference.
The
knee is more proximal to the hip than the ankle. The lumbar spine (low back) is
more proximal to the sacrum (tailbone) than the sternum (breast bone).
Anatomic Locations: Distal
Refers to a position away from the center of the body or point of reference.
The
ankle is more distal to the hip than the knee. The sternum is more distal to the
sacrum than the lumbar spine.
Anatomic Locations: Anterior
Refers to a position on or toward the front of the body.
The quadriceps are
located on the anterior aspect of the thigh.
Anatomic Locations: Posterior (or Dorsal)
Refers to a position on or toward the back of the body.
The hamstring complex
is located on the posterior aspect of the thigh.
Anatomic Locations:Medial
Refers to a position relatively closer to the midline of the body.
The adductors(inner thigh muscles) are on the medial side of the thigh, because they are on the
side of the limb closest to the midline of the body. The sternum is more medial than
the shoulder.
Anatomic Locations: Lateral
Refers to a position relatively farther away from the midline or toward the outside
of the body.
The ears are on the lateral side of the head.
Anatomic Locations: Contralateral
Refers to a position on the opposite side of the body.
The right foot is
contralateral to the left hand.
Anatomic Locations: Ipsilateral
Refers to a position on the same side of the body.
The right foot is ipsilateral
to the right hand.
Anatomic Position
The position
with the body erect with the
arms at the sides and the palms
forward. The anatomic position
is of importance in anatomy
because it is the position of reference
for anatomic nomenclature.
Anatomic terms such as anterior
and posterior, medial and lateral,
and abduction and adduction
apply to the body when it is in the
anatomic position.
Sagittal Plane
An imaginary
bisector that divides the body
into left and right halves.
Examples
of predominantly sagittal plane movements include biceps curls, triceps pushdowns,
squats, front lunges, calf raises, walking, running, vertical jump, climbing stairs, and
shooting a basketball.
Sagittal Plane Movement:Flexion
A bending movement
in which the relative angle
between two adjacent segments
decreases.
Sagittal Plane Movement: Extension
A straightening
movement in which the relative
angle between two adjacent
segments increases.
Sagittal Plane Movement: Hyperextension:
Extension of
a joint beyond the normal limit or
range of motion.
Frontal Plane
An imaginary
bisector that divides the body
into front and back halves.
Examples of frontal plane movements include side lateral raises, side lunges, and side
shuffl ing.
Frontal Plane Movement: Abduction
A movement in
the frontal plane away from the
midline of the body.
Frontal Plane Movement: Adduction
Movement in the
frontal plane back toward the
midline of the body.
Transverse Plane
An i maginary
bisector that divides the body into
top and bottom halves.
Examples of transverse plane movements include cable trunk
rotations, dumbbell chest fl y, throwing a ball, throwing a Frisbee, golfi ng, and swinging
a bat.
Transverse Plane Movement: Horizontal Abduction
Movement
of the arm or thigh in the
transverse plane from an anterior
position to a lateral position.
Transverse Plane Movement: Horizontal Adduction
Movement
of the arm or thigh in the
transverse plane from a lateral
position to an anterior position.
Scapular Retraction
Adduction
of scapula; shoulder blades
move toward the midline.
Scapular Protraction
Abduction
of scapula; shoulder blades
move away from the midline.
Scapular Depression
Downward
(inferior) motion of the
scapula.
Scapular Elevation
Upward
(superior) motion of the scapula.
Three primary types of muscle actions
Isotonic (constant muscle tension)
Eccentric
Concentric
Isometric (constant muscle length)
Isokinetic (constant velocity of motion)
Muscle Action: Isotonic
Force is produced, muscle tension is developed, and movement occurs through
a given range of motion
Divided in to 2 parts: Eccentric and Concentric
Muscle Action: Isotonic Eccentric
Moving in the same direction as the resistance
Decelerates or reduces force.
An eccentric motion is synonymous with deceleration and can be observed in many
movements such as landing from a jump, or more commonly seen in a gym as lowering
the weight during a resistance exercise
Muscle Action: Isotonic Concentric
Moving in opposite direction of force
Accelerates or produces force
A concentric muscle action is
synonymous with acceleration and can be observed in many movements such as jumping
upward, and the “lifting” phase during resistance training exercise.
Muscle Action: Isometric
No visible movement with or against resistance
Dynamically stabilizes force.
In activities of daily living and sports, isometric actions are used to dynamically
stabilize the body. This can be seen in muscles that are isometrically stabilizing a limb
from moving in an unwanted direction
Muscle Action: Isokinetic
The speed of movement is fi xed, and resistance varies with the force exerted
Requires sophisticated training equipment often seen in rehabilitation or
exercise physiology laboratories
During a full isokinetic contraction, the tension in
the muscle is at its maximum throughout the whole range of motion, which is believed
to improve strength, endurance, and neuromuscular effi ciency.
Length-Tension Relationship
the resting length of a muscle
and the tension the muscle can
produce at this resting length.
It is important for personal trainers to understand the length-tension relationship
because if muscle lengths are altered, for example, misaligned joints (i.e., poor posture),
then they will not generate the needed force to allow for effi cient movement. If
one component of the HMS (nervous, skeletal, or muscular) is not functioning as it
should, it will have a direct effect on the effi ciency of human movement.
Force-Velocity Curve
The force-velocity curve refers to the relationship of muscle’s ability to produce tension
at differing shortening velocities (Figure 5.13). As the velocity of a concentric muscle
action increases, its ability to produce force decreases
Force-Couple Relationship
Muscle groups
moving together to produce
movement around a joint.
Because muscles are recruited as groups, many muscles will transmit force
onto their respective bones, creating movement at the joints
Muscle Action
every movement produced must involve all muscle actions
(eccentric, isometric, concentric) and all functions (agonists, synergists, stabilizers, and
antagonists) to ensure proper joint motion as well as to eliminate unwanted or unnecessary
motion.
Muscle Leverage and Arthrokinematics
The amount of force that the HMS can produce is not only dependent on motor unit
recruitment and muscle size, but also the lever system of the joint.
Particular attachments of muscles to bones will determine how much
force the muscle is capable of generating.
Rotary Motion
Movement of
the bones around the joints.
Motor Behavior
Motor
response to internal and external
environmental stimuli.
Motor Control
How the
central nervous system integrates
internal and external sensory
information with previous
experiences to produce a motor
response.
Motor Learning
Integration of
motor control processes through
practice and experience, leading
to a relatively permanent change
in the capacity to produce skilled
movements.
Motor Development
The
change in motor skill behavior
over time throughout the
lifespan.
Muscle Synergies
Groups of
muscles that are recruited by the
central nervous system to provide
movement.
This simplifi es
movement by allowing muscles and joints to operate as a functional unit. Through
practice of proper movement patterns (proper exercise technique), these synergies
become more fl uent and automated.
Proprioception
The cumulative
sensory input to the central
nervous system from all mechanoreceptors
that sense body
position and limb movements.
Sensorimotor Integration
The cooperation of the nervous
and muscular system in gathering
and interpreting information and
executing movement.
Individuals that train using improper form will develop improper
sensory information delivered to the central nervous system, leading to movement compensations
and potential injury.
Feedback in Motor Learning
The use of sensory
information and sensorimotor
integration to help the human
movement system in motor
learning.
Internal Feedback
The
process whereby sensory
information is used by the body
to reactively monitor movement
and the environment.
External Feedback
Information provided by some
external source, such as a
health and fi tness professional,
videotape, mirror, or heart rate
monitor, to supplement the
internal environment.
Two Type of External Feedback
Knowledge of results is used after the
completion of a movement to help inform a client about the outcome of the performance.
Knowledge of performance provides information about the quality of the movement
during an exercise.
