Chapter 7 - Lesson 5

Question 1

Force

Answer 1

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

Question 2

Length-tension relationship

Answer 2

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

Question 3

Resting length

Answer 3

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

Question 4

Actin

Answer 4

The thin, stringlike, myofilament that acts along with myosin to produce muscular contraction.

Question 5

Myosin

Answer 5

The thick myofilament that acts along with actin to produce muscular contraction.

Question 6

Sarcomere

Answer 6

The structural unit of a myofibril composed of actin and myosin filaments between two Z-lines.

Question 7

Muscle balanca

Answer 7

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

Question 8

Altered length-tension relationship

Answer 8

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

(Muscle imbalance)

Question 9

Reciprocal inhibition

Answer 9

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

Question 10

Altered reciprocal inhibition

Answer 10

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

Question 11

Muscle Imbalance

Answer 11

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

Question 12

Neutral Position

Answer 12

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

Question 13

Stretch-shortening cycle

Answer 13

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

Question 14

Series elastic component

Answer 14

Springlike non contractile component of muscle and tendon that stores elastic energy.

*Ex: getting into a squat position

Question 15

Amortization phase

Answer 15

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

Question 16

Stretch reflex

Answer 16

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

Question 17

Integrated performance paradigm

Answer 17

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

Question 18

Tendons

Answer 18

A fibrous connective tissue that connects muscle to bone.

Question 19

Force-couple relationship

Answer 19

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

Question 20

Local muscular system

Answer 20

Local muscles generally attach on or near the vertebrae and serve the primary purpose of stabilizing the trunk of the body. The local muscular system is composed of the inner unit of the core and includes the rotatores, multifidus, transversus abdominis, diaphragm, pelvic floor, and quadratus lumborum.

Question 21

Joint support systems

Answer 21

Muscular stabilization systems located in joints distal of the spine.

Question 22

Global muscular system

Answer 22

The global muscular system is comprised of larger muscles that initiate movements and tend to function across one or more joints (Okubo et al., 2010). These muscles are generally larger and act as prime movers during many functional tasks, such as pushing, pulling, squatting, and walking. Because of this, the global muscular system is commonly referred to as the movement system. Examples of global muscles include the rectus abdominis, erector spinae, and latissimus dorsi.

Question 23

Deep longitudinal subsystem (DLS)

Answer 23

Includes muscles of the lower leg, hamstrings, and lower back region

Question 24

Posterior oblique subsystem (POS)

Answer 24

Includes latissimus dorsi, thoracolumbar fascia (connective tissue of the low-back), and contralateral gluteus maximus

Question 25

Anterior oblique subsystem (AOS)

Answer 25

Includes obliques, the adductor (inner) thigh muscles, and the hip external rotators

Question 26

Lateral subsystem (LS)

Answer 26

Include lateral hip (gluteus medius) and medial thigh muscles (adductors) and the contralateral quadratus lumborum, all of which provide movement in the frontal plane

Question 27

First-class levers

Answer 27

First-class levers have the fulcrum in the middle, like a seesaw. Nodding the head is an example of a first-class lever, with the top of the spinal column as the fulcrum (Levangie et al., 2019).

Question 28

Second-class levers

Answer 28

Second-class levers have a resistance in the middle with the fulcrum and effort on either side, similar to a load in a wheelbarrow where the axle and wheel are the fulcrum points.

Calf-raise

Question 29

Second-class levers

Answer 29

Third-class levers have the effort placed between the resistance and the fulcrum

An example of a third-class lever is the human forearm; the fulcrum is the elbow, the effort is applied by the biceps brachii muscle, and the load is in the hand, such as a dumbbell when performing a biceps curl.

Question 30

Rotary-motion

Answer 30

Movement of the bones around the joints.

*Example - A gymnast swinging on the rings

Question 31

Torque

Answer 31

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

An example of torque is using a wrench to loosen a bolt. The wrench serves as a lever, and torque would be a product of the force applied to the wrench and the length of the wrench’s handle.