Chapter 5: Human Movement Science Flashcards
biomechanics
the science concerned with the internal and external forces acting on the human body and the effects produced by these forces
superior (or cranial)
positioned above a point of reference
inferior (or caudal)
positioned below a point of reference
proximal
positioned nearest the center of the body, or point of reference
distal
positioned farthest from the center of the body, or point of reference
anterior (or ventral)
on the front of the body
posterior (or dorsal)
on the back of the body
medial
positioned near the middle of the body
lateral
positioned toward the outside of the body
contralateral
positioned on the opposite side of the body
ipsilateral
positioned on the same side of the body
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
flexion
a bending movement in which the relative angle between two adjacent segments decreases
extension
a straightening movement in which the relative angle between two adjacent segments increases
hyperextension
extension of a joint beyond its normal limit or range of motion
frontal plane
an imaginary bisector that divides the body into front and back halves
abduction
- a movement in the frontal plane away from the midline of the body
- an increase in the angle between two adjoining segments
adduction
- movement in the frontal plane back toward the midline of the body
- a decrease in the angle between two adjoining segments
transverse plane
an imaginary bisector that divides the body into top and bottom halves
internal rotation
rotation of a joint toward the middle of the body
external rotation
rotation of a joint 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 of tight 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
eccentric muscle action
-an eccentric muscle action occurs when a muscle develops tension while lengthening
concentric muscle action
when a muscle is exerting force greater than the resistive force, resulting in shortening of the muscle and visible joint movement
isometric muscle action
when a muscle is exerting force equal to the force being place on it leading to no visible change in muscle length
isokinetic muscle action
when a muscle shortens at a constant speed over the full range of motion
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
force-couple
muscle groups moving together to produce movement around a joint
rotary motion
movement of the bones around the joints
torque
a force that produces rotation. common unit of torque is the newton-meter or Nm.
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
- the study of posture and movements with the involved structures and mechanisms used by the CNS to assimilate and integrate sensory information with previous experiences
- concerned with what CNS structures are involved with motor behavior to produce movement
motor learning
- integration of motor control processes through practice and experience, leading to a relatively permanent change in the capacity to produce skilled movements
- the utilization of motor control processes through practice and experience, leading to a relatively permanent change in one’s 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
proprioception
the cumulative sensory input to the central nervous system from all mechanoreceptors that sense position and limb movements
sensorimotor integration
the cooperation of the nervous and muscular system in gathering and interpreting information and executing movement
feedback
- the use of sensory information and sensorimotor integration to help the human movement system in motor learning
- the utilization of sensory information and sensorimotor integration to aid the HMS in the development of permanent neural representations of motor patterns
internal feedback
-the process whereby sensory information is used by the body via length-tension relationships (posture) to reactively monitor movement and the environment (aka sensory feedback)
external feedback
information provided by some external source, such as a health and fitness professional, videotape, mirror, or heart rate monitor, to supplement the internal environment
human movement efficiency cycle
> internal environment > external environment > summation of all information > central nervous system > movement >
the femur is ___ to the tibia
superior
the pectoralis major is ___ to the rectus abdominis
superior
the calcaneus is ___ to the patella
inferior
the soleus is ___ to the hamstring complex
inferior
which is more proximal to the hip: the knee or the ankle?
the knee
which is more proximal to the lumbar spine: the sacrum or the sternum?
the sacrum
which is more distal to the hip: the ankle or the knee?
the ankle
which is more distal to the lumbar spine: the sacrum or the sternum?
the sternum
the quadriceps are located on the ___ aspect of the thigh
anterior
the hamstring complex is located on the ___ aspect of the thigh
posterior
the adductors are on the ___ side of the thigh
medial
which is more medial: the sternum or the shoulder?
the sternum
the ears are on the ___ side of the head
lateral
the right foot is ___ to the left hand
contralateral
the right foot is ___ to the right hand
ipsilateral
true or false: no motion occurs strictly in one plane of motion
TRUE
joint motion
movement in a plane occurs on an axis running perpendicular that plane
sagittal plane axis
coronal
sagittal plane motions
- flexion / extension
sagittal plane exercise examples
- biceps curl
- triceps pushdown
- squat
- front lunge
- calf raise
- walking
- running
- vertical jumping
- climbing
- shooting a basketball
frontal plane axis
anterior-posterior
frontal plane motions
- adduction / abduction in the limbs
- lateral flexion of the spine
- eversion / inversion at the foot and ankle complex
frontal plane exercise examples
- side lateral raise
- side lunge
- side lunge
- side shuffling
transverse plane axis
longitudinal
transverse plane motions
- internal / external rotation for the limbs
- left / right rotation for head and trunk
- horizontal adduction / abduction of the limbs
- radioulnar (forearm) pronation and supination
transverse plane exercise examples
- trunk rotation
- dumbbell chest fly
- throwing a ball or frisbee
- golfing
- swinging a bat
dorsiflexion
flexion at the ankle
plantar flexion
extension at the ankle
hip flexion
- occurs when an individual decreases the angle between the femur (thigh bone) and the pelvis or lumbar spine
- ex) elevate knee towards abdomen
- ex) bend forward from the trunk
lateral flexion
the bending of the spine from side to side or simply side-bending
retraction is the same as ___
adduction
protraction is the same as ___
abduction
3 primary types of muscle actions
- isotonic (Eccentric and concentric)
- isometric
- isokinetic
2 components of an isotonic movement
- eccentric phase
2. concentric phase
isotonic performance
force is produced, muscle tension is developed, and movement occurs through a given range of motion
eccentric performance
moving in the same direction as the resistance, decelerates or reduces force
concentric performance
moving in opposite direction of force, accelerates or produces force
isometric performance
no visible movement with or against resistance, dynamically stabilizes force
isokinetic performance
- the speed of the movement is fixed, and resistance varies with the force exerted
- requires sophisticated training equipment often seen in rehabilitation or exercise physiology laboratories
why does the muscle lengthen in an eccentric muscle action?
because the contractile force is less than the resistive force
what happens to the actin and myosin cross-bridges as the muscle lengthens?
they are pulled apart and reattach
eccentric motion examples
- landing from a a jump
- lowering a weight during a resistance exercise
eccentric muscle is also known as a “__”
negative
true or false: in eccentric movement, work is actually being done on the muscle rather than the muscle doing the work
TRUE
what happens to the actin and myosin cross-bridges as the muscle shortens?
they move together (known as sliding-filament theory)
concentric motion examples
- jumping upward
- the “lifting” phase during a resistance training exercise
how are isometric actions used in activities of daily living and sports?
to dynamically stabilize the body
isometric motion examples
- the adductors and abductors of the thigh during a squat will dynamically stabilize the leg from moving too much in the frontal and transverse planes
- during a ball crunch, the transversus abdominis and multifidus (deep spine muscles) stabilize the lumbar spine
- during dumbbell bench press, the rotator cuff musculature dynamically stabilizes the shoulder joint
what does an isokinetic muscle action require?
the use of expensive and sophisticated equipment that measures the amount of force generated by the muscles and adjusts the resistance (load) so that no matter how much muscular tension is produced, movement remains constant
-aka the harder an individual pushes or pulls, the more resistance they feel
during a full isokinetic contraction, where is the tension in the muscle at its maximum?
throughout the whole range of motion
what are the benefits of isokinetic muscle actions?
improves strength, endurance, and neuromuscular efficiency
concentric phase of a bicep curl
-the initial movement requires the biceps to shorten to generate force to overcome gravity and the weight of the dumbbell, allowing the elbows to flex and the dumbbells to move up toward the front of the shoulder
isometric phase of a bicep curl
- once the dumbbells are raised to the front of the shoulder, the individual holds this position
- because the length of the muscle does not change while holding this position, but the biceps are stilly applying force and under tension, this is considered the isometric portion of the exercise
eccentric phase of a bicep curl
-as the individual lowers the dumbbells down back to the starting position, the biceps now lengthen (under the control of the nervous system) to decelerate the force of the dumbbells and gravity
eccentric phase of a squat
- to initiate the squat from a standing position the individual squats down, flexing at the hips, knees, and ankles
- the individual is in the “lowering” phase of the resistance exercise
- moreover, as the individual squats downward, the gluteal muscle sand quadriceps mechanically lengthen while simultaneously decelerating the force of their body weight and gravity
isometric phase of a squat
-when the individual pauses at the bottom position and no joint motion is visible
concentric phase of a squat
-when the individual returns to the starting position (lifting phase), contracting the gluteal muscles and quadriceps
true or false: muscles usually work in isolation
- FALSE
- rarely do muscles work in isolation
- it is important to view muscles functioning in all planes of motion and through the entire muscle action spectrum
- in addition, several muscles work synergistically to produce force, stabilize the body, and reduce force under direct control of the nervous system
what are forces characterized by?
- magnitude (how much)
2. direction (which way they are moving)
optimal muscle length
- when the actin and myosin filaments in the sarcomere have the greatest degree of overlap
- this results in the ability of myosin to make a maximal amount of connections with actin and thus results in the potential for maximal force production of that muscle
what happens when you lengthen a muscle beyond its optimal length?
lengthening a muscle beyond its optimal length and then stimulating it reduces the amount of actin and myosin overlap, reducing force production
what happens when you shorten a muscle too much?
shortening a muscle too much and then stimulating it places the actin and myosin in a state of maximal overlap and allows no further movement to occur between the filaments, reducing its force output
the force-velocity curve
refers to the relationship of muscle’s ability to produce tension at differing shortening velocities
what happens as the velocity of a concentric muscle action increases?
- its ability to produce force decreases
- this is thought to be the result of overlapping the actin filament that may interfere with its ability to form cross-bridges with myosin
what happens as the velocity of an eccentric muscle action increases?
- the ability to develop force increases
- this is believed to be the result of the use of the elastic component of the connective tissue surrounding and within the muscle
how is the force that muscles produce transmitted to bones?
through their connective tissues (tendons)
what do muscles in a force-couple do?
- provide divergent pulls on the bone or bones they connect with
- this is a result of the fact that each muscle has different attachment sites, pulls at a different angle, and creates a different force on that joint
- the motion that results from these forces is dependent on the structure of the joint and the collective pull of each muscle involved
what allows for proper sensorimotor integration (and ultimately proper and efficient movement)?
- proper length-tension relationships
- force-couple relationships
- arthrokinematics
movement created by internal and external obliques (force-couple)
trunk rotation
movement created by upper trapezius and lower portion of the serratus anterior (force-couple)
upward rotation of the scapula
movement created by the gluteus maximus, quadriceps, and calf muscles (force-couple)
produce hip and knee extension during walking, running, stair climbing, etc.
movement created by the gastrocnemius, peroneus longus, and tibialis posterior (force-couple)
performing plantarflexion at the foot and ankle complex
movement created by the deltoid and rotator cuff
performing shoulder abduction
the amount of force that the HMS can produce depends on what 3 factors?
- motor unit recruitment
- muscle size
- the lever system of the joint
skeletal muscles are attached to bone by ___
tendons
what is joint motion caused by?
muscles pulling on bones
true or false: muscles cannot actively push
TRUE
what does a lever consist of?
a rigid “bar” that pivots around a stationary fulcrum (pivot point)
in the human body, what is the fulcrum and what is the lever?
fulcrum = the joint axis levers = bones
first-class lever
fulcrum in the middle, like a seesaw
first-class lever example
nodding the head, with the top of the spinal column as the fulcrum (joint axis)
second-class lever
resistance in the middle (with the fulcrum and effort on either side), like a load in a wheelbarrow
second-class lever example
full-body pushup or calf raise
-in a calf raise, the ball of the foot is the fulcrum, the body weight is the resistance, and the effort is applied by the calf musculature
third-class lever
- effort placed between the resistance and the fulcrum
- the effort always travel a shorter distance and must be greater than the resistance
most limbs of the body operate as what kind of lever?
third-class lever
third-class lever example
the human forearm
-the fulcrum is the elbow, the effort is applied by the biceps muscle, and the load is in the hand such as a dumbbell when performing a biceps curl
the amount of leverage the HMS will have (for any given movement) depends on what?
the leverage of the muscles in relation to the resistance
what determines the efficiency with which the muscles manipulate the movement/.
the difference between the distance that the weight is from the center of the joint and the muscle’s attachment and line of pull (direction through which tension is applied through the tendon) is from the joint
what is the easiest way to alter the amount of torque generated at a joint?
move the resistance (since we cannot alter the attachment sites or the line of pull of our muscles through the tendon)
the closer the weight is to the point of rotation (the joint), the ____ torque it creates
less
the farther away the weight is from the point of rotation, the ___ torque it creates
more
what is the prime mover for shoulder abduction?
the deltoid muscle
what does the study of motor behavior examine?
the manner by which the nervous, skeletal, and muscular systems interact to produce skilled movement using sensory information from internal and external environments
motor behavior is the collective study of what 3 things?
- motor control
- motor learning
- motor development
in order to move in an organized and efficient manner, what must the HMS exhibit?
precise control over its collective segments
-this segmental control is an integrated process involving neural, skeletal, and muscular components to produce appropriate motor responses
how to muscle synergies simplify movement?
by allowing muscles and joints to operate as a functional unit
how to muscle synergies become more fluent and automated?
through practice of proper movement patterns (proper exercise technique)
where does proprioception use information from?
the mechanoreceptors (muscle spindle, Golgi tendon organ, and joint receptors)
what does proprioception provide information about?
body position, movement, and sensation as it pertains to muscle and joint force
why is proprioception a vital source of information?
it allows the nervous system to gather information about the environment and produce the most efficient movement
true or false: proprioception is altered after injury
TRUE
what percentage of the adult population experiences lower-back pain?
80%
how can core and balance training enhance one’s proprioceptive capabilities?
increasing postural control and decreasing tissue overload
squat muscle synergies
quadricep, hamstring complex, gluteus maximus
shoulder press muscle synergies
deltoid, rotator cuff, trapezius
sensorimotor integration is effective as long as what?
the quality of incoming sensory information is good
what happens when individuals train using improper form?
they will develop improper sensory information delivered to the central nervous system, leading to movement compensations and potential injury
what can be altered with improper form?
- length-tension relationships (muscle length)
- force-couple relationships (improper recruitment pattern of muscles)
- arthrokinematics (improper joint motion)
what must happen for a movement to occur repeatedly?
sensory information and sensorimotor integration must be used to aid the HMS in the development of permanent neural representations of motor patterns, a process referred to as feedback
what does feedback allow for?
efficient movement
how does internal (sensory) feedback act as a guide?
it steers the HMS to the proper force, speed, and amplitude of movement patterns
what does external feedback provide the client with?
another source of information that allows him or her to associate whether the achieved movement pattern was “good” or “bad” with what he or she is feeling internally
2 major forms of external feedback
- knowledge of results
2. knowledge of performance
knowledge of results
feedback used after the completion of a movement to help inform the client about the outcome of his performance
knowledge of results example
telling a client that his squats were “good” and asking the client if he could “feel” or “see” is form
knowledge of performance
feedback that provides information about the quality of the movement during the exercise
knowledge of performance example
noticing that during a squat, the client’s feet were externally rotated and her knees were excessively adducting, then asking the client if she felt or saw anything different about those reps
how is knowledge of results beneficial for a client?
- it increases their awareness and other forms of sensory feedback, leading to more effective exercise technique
- improves neuromuscular efficiency
when should knowledge of results be used?
after each rep, after a few reps, or after the set is completed
how is knowledge of performance beneficial to the client?
it gets them involved in his or her own sensory process
what do knowledge of results and performance allow for?
- the identification of performance errors
- more effective performance outcomes in the future
- important outcome of motivation
- supplemental sensory input for the client to help create an awareness of the desired action
what happens if a client becomes dependent on external feedback?
- it may detract from their responsiveness to internal sensory input, or internal motivation
- it can negatively affect sensorimotor integration and motor learning, and ultimately movement patterns
true or false: each system of the HMS (kinetic chain) is interdependent
TRUE
-all of the segments and processes in the entire chain must work together to gather information from internal and external environments to create and learn movements (or motor behavior)
what does the body use to create efficient movement (or motor control)?
proprioception, sensorimotor integration, and muscle synergies
