Chapter 7: Human Movement Science

Torque

A force that produces rotation; common unit of measurement is the Newton meter (Nm).

Motor Unit

A motor neuron and all of the muscle fibers it innervates

Abduction

A movement in the frontal plane away from the midline of the body

Eversion

A movement in which the inferior calcaneus (heel bone) moves laterally. Bottom of foot faces outward.

Inversion

A movement in which the inferior calcaneus (heel bone) moves medially. Bottom of foot faces inward.

Eccentric Muscle Action

A muscle action that occurs when a muscle develops tension while lengthening.

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.

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.

Extension

A straightening movement in which the relative angle between two adjacent segments increases.

Scapular Protraction

Abduction of scapula; shoulder blades move away from the midline.

Antagonists

Muscles on the opposite side of a joint that are in direct opposition of agonist muscles.

Synergists

Muscles that assist agonists to produce a movement.

Stabilizers

Muscles that contract isometrically to stabilize the trunk and joints as the body moves.

Joint Support Systems

Muscular stabilization systems located in joints distal of the spine.

Stretch Reflex

Neurological signal from the muscle spindle that causes a muscle to contract to prevent excessive lengthening.

Altered Reciprocal Inhibition

Occurs when an overactive agonist muscle decreases the neural drive to its functional antagonist.

Radioulnar Supination

Outward rotation of the forearm from a palm-down position to a palm-up position.

What is the scientific term that describes the nervous system's role in the contract/relax relationship between agonists and antagonists? Stretch-shortening cycle Length-tension relationship Muscle imbalance Reciprocal inhibition

Reciprocal inhibition

The upper trapezius works with what muscle as a force couple to create upward rotation of the scapula? Serratus anterior Rhomboids Rotator cuff muscles Deltoid

Serratus Anterior

Mechanoreceptors

Specialized structures that respond to mechanical forces (touch and pressure) within tissues and then transmit signals through sensory nerves.

Series Elastic Component

Springlike noncontractile component of muscle and tendon that stores elastic energy.

What does the term force refer to?

The ability of one entity to act on another entity, causing acceleration or deceleration

Elasticity

The ability of soft tissues to return to resting length after being stretched.

Neuromuscular Efficiency

The ability of the nervous system to recruit the correct muscles to produce force, reduce force, and dynamically stabilize the body's structure in all three planes of motion.

Feed-Forward Activation

When a muscle is automatically activated in anticipation of a movement.

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. ex. a plank

Altered Length-Tension Relationship

When a muscle's resting length is too short or too long, reducing the amount of force it can produce.

Muscle Balance

When all muscles surrounding a joint have optimal length-tension relationships, allowing the joint to rest in a neutral position.

Reciprocal Inhibition

When an agonist receives a signal to contract, its functional antagonist also receives an inhibitory signal allowing it to lengthen.

Muscle Imbalance

When muscles on each side of a joint have altered length-tension relationships.

Hypomobility

When range of motion at a joint is limited.

Posterior

back of body

Dorsiflexion

bending of the foot or the toes upward (flexion)

Anterior

front of the body

Contralateral

on the opposite side of the body

Ipsilateral

on the same side of the body

Flexion

A bending movement in which the relative angle between two adjacent segments decreases.

Kinetic Chain

A concept that describes the human body as a chain of interdependent links that work together to perform movement.

Ligament

A fibrous connective tissue that connects bone to bone.

Tendon

A fibrous connective tissue that connects muscle to bone.

Scapular Retraction

Adduction of scapula; shoulder blades move toward the midline.

Closed-Chain Movements

An exercise where the end of the chain farthest from the body is fixed, such as a squat where the feet are fixed on the ground and the rest of the leg chain moves

Open-Chain Movements

An exercise where the end of the chain farthest from the body is free, such as a seated leg extension

Frontal Plane

An imaginary bisector that divides the body into front and back halves. Abduction, adduction, and side-to-side motions

Sagittal Plane

An imaginary bisector that divides the body into left and right halves. flexion/extension

Transverse Plane

An imaginary bisector that divides the body into top and bottom halves.

Lateral Flexion

Bending of the spine from side to side.

Force

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

Which of the following statements would be accurate with regard to muscle force and velocity during a concentric contraction? As the velocity of a concentric muscle action decreases, its ability to produce force decreases. As the velocity of a concentric muscle action increases, its ability to produce force increases. As velocity decreases, the force remains constant. As the velocity of the muscle action increases, its ability to produce force decreases

As the velocity of the muscle action increases, its ability to produce force decreases

Lateral

Away from the midline of the body

Gait

Biomechanical motion of the lower extremities during walking, running, and sprinting.

What is the anatomical term that describes something positioned on the opposite side of the body? Ipsilateral Contralateral Posterior Lateral

Contralateral

Sensorimotor Integration

Cooperation of the nervous and muscular system in gathering and interpreting information and executing movement.

The muscles of the lower leg, hamstrings, and low back region make up which of the following global muscular subsystems?

Deep longitudinal subsystem (DLS)

Scapular Depression

Downward (inferior) motion of the scapula.

Plantar Flexion

Extension occurring at the ankle. Pointing the foot downward

Hyperextension

Extension of a joint beyond the normal limit or range of motion

TRUE OR FALSE? The primary characteristic of closed-chain movements is that the distal segments, such as the person's hands or feet, are not fixed and are able to move freely.

False

What is the concept used to describe the action of muscles that have the ability to contract automatically in anticipation of movement? Antagonist function Synergist function Feed-forward Feedback

Feed-forward

What type of lever could be described as having a fulcrum in the middle like a seesaw? Second class Third class First class Fourth class

First class

Isotonic

Force is produced, muscle tension is developed, and movement occurs through a given range of motion. eccentric or concentric muscle actions

Muscle Synergies

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

During a squat, which muscle group isometrically contracts to prevent unnecessary thigh movement in the frontal plane? Hip extensors Hip internal rotators Hip flexors Hip abductors

Hip abductors

Motor Control

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

Which of the following benefits may occur as a result of exercises that comprise only eccentric muscle actions that are appropriately loaded? Decreased catabolic hormone stimulation Decreased anabolic hormone stimulation Increased catabolic hormone stimulation Increased anabolic hormone stimulation

Increased anabolic hormone stimulation

External Feedback

Information provided by some external source, such as a fitness professional, video, mirror, or heart rate monitor, to supplement the internal environment.

Motor Learning

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

Radioulnar Pronation

Inward rotation of the forearm from a palm-up position to a palm-down position.

Which type of exercise accommodates effort whereby the harder the individual pushes or pulls, the more resistance they feel, despite the movement speed remaining constant? Eccentric Isometric Isokinetic Concentric

Isokinetic

What term is used to describe muscle tension that is created without a change in muscle length and no visible movement of the joint? Eccentric Concentric Isometric Isokinetic

Isometric

What are the three overarching types of muscle actions?

Isotonic, isometric, and isokinetic

Stretch-Shortening Cycle

Loading of a muscle eccentrically to prepare it for a rapid concentric contraction.

In order to optimally load muscle during the eccentric phase, the fitness professional should recommend which of the following? Reduce the resistance so it is less than it was in the concentric phase, and lower the weight faster to reduce time under tension Lower the weight faster to reduce time under tension Lower the weight more slowly to increase time under tension Reduce the resistance so it is less than it was in the concentric phase, and lower the weight more slowly to increase time under tension

Lower the weight more slowly to increase time under tension

Motor Behavior

Motor response to internal and external environmental stimuli.

Adduction

Movement in the frontal plane back toward the midline of the body

Osteokinematics

Movement of a limb that is visible.

Horizontal Adduction

Movement of the arm or thigh in the transverse plane from a lateral position to an anterior position

Horizontal Abduction

Movement of the arm or thigh in the transverse plane from an anterior position to a lateral position

Rotary Motion

Movement of the bones around the joints

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.

One of the most important concepts in motor control is that muscles are recruited by the nervous system in groups. What are these groups called?

Muscle Synergies

Which of the following solutions would allow an individual to achieve a greater depth during the lowering phase of the squat if ankle stiffness is the cause? Stretch the ankle dorsiflexor musculature Stretch the ankle eversion musculature Place a small board under the heels Place a small board under the toes

Place a small board under the heels

Superior

Positioned above a point of reference.

Inferior

Positioned below a point of reference

Distal

Positioned farthest from the center of thebody or other identified reference point

Proximal

Positioned nearest to the center of the bodyor other identified reference point

Which of the following muscle groups work both eccentrically and concentrically in the sagittal plane during a squat? Biceps brachii Quadriceps Adductor longus Gluteus medius

Quadriceps

External Rotation

Rotation of a joint away from the middle of the body.

Internal Rotation

Rotation of a joint toward the middle of the body.

What movement term is used to describe the concept of adducting the shoulder blades so that they become closer together? Scapular depression Scapular protraction Scapular elevation Scapular retraction

Scapular retraction

What scientific term is used to describe the concept whereby a loaded eccentric contraction prepares the muscles for a rapid concentric contraction? Stretch-shortening cycle Reciprocal inhibition Series elastic component Altered reciprocal inhibition

Stretch-shortening cycle

Which concept should be used to describe the functioning of the serratus anterior as it assists the anterior deltoid during shoulder flexion? Agonist Stabilizer Antagonist Synergist

Synergist

Proprioception

The body's ability to naturally sense its general orientation and relative position of its parts.

Motor Development

The change in motor skill behavior over time throughout the lifespan.

Human Movement System (HMS)

The collective components and structures that work together to move the body: muscular, skeletal, and nervous systems.

Regional Interdependence Model

The concept describing the integrated functioning of multiple body systems or regions of the body.

Arthrokinematics

The description of joint surface movement; consists of three major types: roll, slide, and spin.

Muscle Action Spectrum

The full range of eccentric, isometric, and concentric muscle contractions required to perform a movement.

Resting Length

The length of a muscle when it is not actively contracting or being stretched.

Flexibility

The normal extensibility of soft tissues that allows for full range of motion of a joint.

Neutral Postion

The optimal resting position of a joint that allows it to function efficiently through its entire normal range of motion

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.

Agonist

The primary muscles providing force for a movement.

Internal Feedback

The process whereby sensory information is used by the body to reactively monitor movement and the environment

What concept describes how the function of one segment of the body can impact other areas?

The regional interdependence model

Length-Tension Relationship

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

What is the imaginary line that bisects the body into right and left sides?

The sagittal plane

Biomechanics

The science concerned with the internal and external forces acting on the human body and the effects produced by these forces.

Isokinetic

The speed of movement is fixed, and resistance varies with the force exerted.

Core

The structures that make up the lumbo-pelvic-hip complex (LPHC), including the lumbar spine, pelvic girdle, abdomen, and hip joint.

Force-Couple Relationship

The synergistic action of multiple muscles working together to produce movement around a joint.

How should the amortization phase of the stretch-shortening cycle be described? The transition between the concentric and isometric phases The transition from eccentric loading to concentric unloading The transition between the isometric and eccentric phases The transition from concentric loading to eccentric unloading

The transition from eccentric loading to concentric unloading

Amortization Phase

The transition from eccentric loading to concentric unloading during the stretch-shortening cycle.

The posterior oblique system includes which of the following muscle groups? Hamstrings and erector spinae Adductors (inner thigh) and contralateral quadratus lumborum Adductors (inner thigh) and hip external rotators Thoracolumbar fascia and contralateral gluteus maximus

Thoracolumbar fascia and contralateral gluteus maximus

Integrated Performance Paradigm

To move with efficiency, forces must be dampened (eccentrically), stabilized (isometrically), and then accelerated (concentrically).

What measurement is dependent upon the length of the lever arm and the angle between the force application and the lever arm? Torque Arthrokinematics Force velocity Force

Torque

Medial

Toward the midline of the body

Scapular Elevation

Upward (superior) motion of the scapula.

Feedback

Use of sensory information and sensorimotor integration to help the human movement system in motor learning.