NASM: Chapter 7 - Human Movement Science Part 2

1. Isotonic (eccentric and concentric)

2. Isometric

3. Isokinetic

• Constant muscle tension

• Force is produced, muscle tension develops, and movement occurs through a given range of motion.

• Two types: Eccentric and Concentric

• An eccentric muscle action occurs when a muscle develops tension while lengthening.

• Occurs because the contractile force is less than the resistive force

• "Return to resting length" not actually increasing length as though being stretched.

• Synonymous with deceleration (like bench press, the weight of the bar must be decelerated and then stabilized to be properly accelerated.

• Examples: landing from a jump, lowering weight during resistance exercise, all forms of resistance training (walking on treadmill, bench pressing)

• Known as "a negative" - work is actually being done one the muscle because forces move the muscle, rather than the muscle doing the work (or the muscle moving the forces)

• When a muscle is exerting force greater than the resistive force, resulting in shortening of the muscle and visible joint movement.

• Synonymous with acceleration

• Examples: jumping upward, and the "lifting" phase during resistance training exercise.

• When a muscle is exerting force equal to the force being placed on it leading to no visible change in the muscle length.

• Example: when an individual pauses during a resistance training exercise in between the lifting and lowering phases.

• When a muscle shortens at a constant speed over the full range of motion.

• The tension in the muscle is at its maximum throughout the whole range of motion.

• Believed to improve strength, endurance, and neuromuscular efficiency.

• Requires use of expensive, sophisticated equipment that measures the a out of force generated by the muscles and adjusts the resistance (load) so that no matter how much the muscle tension is produced, movement remains constant (that harder you push, the more resistance/heavier you/it feel/s)

• An influence applied by one object to another, which results in an acceleration or deceleration of the second object.

• Characterized by magnitude (how much) and direction (which way they are moving)

• The resting length of a muscle and the tension of the muscle can produce at this resting length.

• There is an optimal muscle length when actin and myosin filaments have the greatest degree of overlap in sarcomere = potential, for maximal force production of that muscle.

• Lengthening beyond optimal, then stimulating it reduces overlap reducing force production.

• Shortening muscle too much then stimulating it creates maximal overlap and allows no further movement to occur between filaments, reducing force output.

• If muscle lengths are altered (ex. misaligned joints = bad posture), then they will not generate the needed force to allow for efficient movement.

• The relationship of muscle's ability to produce tension at differing shortening velocities.

• As velocity of concentric muscle increases, ability to produce force decreases (results thought to be bc overlapping filament may interfere with its ability to form cross-bridges with myosin)

• As velocity of eccentric muscle action increases, the ability to develop force increases (results thought to be bc elastic component of the connective tissue surrounding and within the muscle).

• Synergistic action of muscles (muscle groups moving together) to produce movement around a joint.

• Provide divergent pulls on the bones or bones the connect with

• Due to the different attachment sites of each muscle, muscles create pulls at a different angle leading to different forces on the joint.

• The motion depends on the structure of the joint and the collective pull of each muscle involved.

• Proper force-couple relationships can only occur if the muscles are at the right length-tension relationships and the joints have proper arthrokinematics (joint motion), thus allowing proper sensorimotor integration and ultimately proper and efficient movement.

1. Muscles: internal and external obliques
   Movement: trunk rotation

2. Muscles: upper trapezius and the lower portion of the serratus anterior
   Movement: upward rotation of the scapula

3. Muscles: gluteus maximus, quadriceps, and calf rotation
   Movement: produce hip and knee extension during walking, running, stair climbing, etc.

4. Muscles: gastrocnemius, peroneus longus, and tibialis posterior
   Movement: performing plantarflexion at the foot and ankle complex

5. Muscles: deltoid and rotator cuff
   Movement: performing shoulder abduction

• A lever consists of a rigid "bar" that pivots around a stationary fulcrum (pivot point).

• In the HMS:

• Fulcrum is the joint axis

• Bones are the levers

• Muscles create motion (effort)

• Resistance can be the weight of the body part, or the weight of an object (barbells and Dumbbells)

1. Fulcrum in middle like a seesaw (nodding head - top of spinal column is fulcrum).

2. Have resistance in the middle with fulcrum and effort on either side like a load in a wheelbarrow (push-up or calf raise - ball of foot fulcrum, body weight is resistance, effort applied by calf musculature).

3. Have effort placed between resistance and the fulcrum, effort travels a shorter distance and must be greater than resistance, most limbs in human body operate as third class levers (forearm- fulcrum is elbow, the effort is applied by the bicep muscle, the load is in the hand like dumbbell when performing bicep curl).

-Movement of levers (bones) that rotate around the axis (joints).

• A force that produces rotation (the turning effect of a joint in a rotary motion).

• Common unit of torque is the newton-meter or Nm.

• Determined by distance that the weight is from the center of the joint and the muscle's attachment and the line of pull (direction tension is being applied through tendon) is from the joint will determine efficiency with which muscles manipulate the movement.

• The closer the weight is to the point of rotation (joint), the less torque it creates.

• The farther the weight is from the point of rotation, the more torque it creates.

• Motor response to internal and external environmental stimuli.

• The study of motor behavior examines the manner by which the nervous, skeletal, and muscular systems interact to produce movement using sensory information from internal and external environments.

• A collective study of motor control, motor learning, and motor development.

• 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.

• How the central nervous system integrates internal and external sensory information with previous experiences to produce a motor response.

-Integration of motor control processes through practice and experience, leading to a relatively permanent change in the capacity to produce skilled movements.

-The change in motor skill behavior over time throughout one's lifespan.

• Groups of muscles that are recruited by the central nervous system to provide movement.

• Simplifies 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 fluent and automated (muscle memory?).

• The cumulative sensory input to the CNS from all mechanoreceptors (muscle spindle, Golgi tendon organ, and joint receptors) that provide information about body position, movement, and sensation as it pertains to muscle and joint force.

• Vital source for the CNS to gather info about environment to produce most efficient movement

• Altered after injury.

• The ability of the nervous system to gather and interpret sensory information and select and execute the proper motor response.

• The cooperation of the nervous and muscular system in gathering and interpreting information and executing the movement.

• Implies that the nervous system dictates movement.

• It is very important to use the correct technique

Continuous performance of the chest press while rounding and elevating shoulders, can lead to:

• Altered length-tension relationships of muscles (altered muscle length)

• Altered force-couple relationships of muscles (improper recruitment pattern of muscles)

• Altered arthrokinematics (improper joint motion)

• Ultimately leads to shoulder impingement or other forms of muscle injury.

The use of sensory information and sensorimotor integration to help the HMS in the development of permanent neural representations of motor patterns/motor learning.

• "Sensory feedback"

• The process whereby sensory information is used by the body via length-tension relationships (posture), force-couple relationships, and arthrokinematics to reactively monitor movement and the environment.

• Acts as a guide, steering HMS to the proper force, speed, and amplitude of movement patterns.

-Information provided by some external source, such as a health and fitness professional, videotape, mirror, or heart rate monitor, to help supplement the internal feedback.

Two major forms:

1. Knowledge of Results: used after completion of a movement to help inform a client about the outcome of the performance. Helps increase clients' awareness and augment other forms of sensory feedback, leading to more effective exercise technique. Improves neuromuscular efficiency.

2. Knowledge of Performance: provides information about the quality of the movement during a exercise. Helps client get involved with his/her own sensory process.

Positioned on the same side of the body.

Concentric acceleration, eccentric acceleration, and isometric stabilization.

Movements in all directions

The muscle that acts as the initial and main source of motive power.