Chapter 7. Human Movement Science

Three Planes of Movement

Sagittal Frontal Transverse

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

Scapular retraction

Motions of The Scapulae

Scapular retraction Scapular protraction Scapular depression Scapular elevation

Frontal Plane

- Front and back - Abduction (away) - Adduction (towards) Lateral flexion (bending of the spine) Eversion (bottom of foot faces outward) Inversion (bottom of foot faces inward)

Sagittal Plane

- Left and right - Flexion (bending) - Extension (straightening) - Dorsiflexion (flexion of the ankle) - Plantar flexion (extension of the ankle) i.e. biceps curls, triceps pushdowns, squats, front lunges, walking, vertical jump, climbing stairs

Transverse Plane

- Upper and lower - Internal rotation (toward) - External rotation (away) Internal and external rotation of the limbs Right and left rotation for the head and trunk Horizontal abduction and adduction of the limbs Radioulnar pronation (inward/palm down) Radioulnar supination (outward/palm up)

Eccentric

- develops tension while lengthening (external force is greater than internal force) - more efficient than concentric - require less energy (fewer motor units required) - referred to as negative work (work is actually being done on the muscle, such as slowing a load being pulled toward the earth by gravity, rather than the muscle doing the work, such as internal muscular forces generated to move a load against gravity. This is related to the fact that eccentric motion moves in the same direction as the resistance is moving, known as direction of resistance)

3 phases of the stretch-shortening cycle

1. eccentric phase 2. amortization phase 3. concentric phase

*Training tip - eccentric

A body of evidence has shown that exercises comprised of only eccentric muscle actions will, when appropriately loaded, stimulate anabolic hormones to a greater degree than exercises comprised of only concentric muscle actions (Franchi et al., 2017; Kraemer & Ratamess, 2005).

How is an isokinetic muscle contraction best described?

A contraction that occurs when the speed of movement is fixed and the resistance varies with the force exerted This defines an isokinetic muscle contraction. Isokinetic muscle contractions require machines that enable a fixed speed throughout a particular range of motion.

Length-Tension Relationships

A length-tension relationship refers to the association between the resting length of a muscle and the amount of internal tension it can produce at that resting length Each muscle in the body has an optimal muscle length at which the actin and myosin filaments within the sarcomere have the greatest degree of overlap At that optimal length, the ability of myosin to make a maximal amount of connections with actin results in the potential for maximal force production of that muscle.

The deep longitudinal subsystem includes which of the following muscle groups?

Adductors (inner thigh) and hip external rotators Hamstrings and erector spinae Adductors (inner thigh) and contralateral quadratus lumborum Thoracolumbar fascia and contralateral gluteus maximus

Isotonic

Force is produced as a muscle develops tension while visibly changing in length. - classified as eccentric or concentric - represent lowering and lifting

3 Categories of Muscle Action

Isotonic (eccentric/concentric) Isometric Isokinetic

Which muscle functions as part of the global muscular system?

Multifidus Internal oblique Transversus abdominis Erector spinae The erector spinae is part of the global muscular system, which is comprised of larger muscles that initiate movements and tend to function across one or more joints.

Antagonist

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

The local muscular system

Muscles that connect to the spine and provide LPHC stabilization. inner unit of the core and includes the rotatores, multifidus, transversus abdominis, diaphragm, pelvic floor, and quadratus lumborum.

What is a key mechanism involved in internal feedback?

Proprioception Proprioception relies on internal feedback that comes primarily from internal biological structures (i.e.., mechanoreceptors).

Stabilizer

Stabilizer muscles contract isometrically to support and stabilize the joints, while the prime movers and synergists move through the entire muscle action spectrum to perform a movement. For example, the transversus abdominis (a deep abdominal muscle), internal obliques, and multifidus (deep muscles of the spine) stabilize the LPHC during hip extension. Another example is the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, and subscapularis), which stabilize the shoulder during upper extremity movements (Day et al., 2012).

What type of input may provide a runner with a cue to contract the evertor muscles to avoid an inversion injury?

Stretch-shortening cycle Proprioception Force velocity External feedback idk this answer

What is the anatomical term that describes something positioned above an identified reference point?

Superior

The 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.

Closed-chain movements

anchor the body to the ground or immovable object (floor, wall, or pull-up bar - hands or feet are fixed/ do not move) i.e. pull-up is a closed-chain exercise for the back musculature

Synergist

assist prime movers but are not intended as the primary force producer for a given joint motion. For example, the hamstring complex and the erector spinae (muscles of the back) are synergistic with the gluteus maximus during hip extension (Kendall et al., 2005), whereas the brachioradialis and brachialis (forearm muscles) assist the biceps brachii during a biceps curl. Additional examples include the triceps brachii assisting the pectoral muscles during a chest press and the biceps brachii assisting the latissimus dorsi during a pull-up.

The global muscle system

can be broken down into subsystems, which include the deep longitudinal, posterior oblique, anterior oblique, and lateral subsystems. 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

Isometric

contractile force = resistive force (no visible change in muscle length) or example, performing a plank exercise requires an isometric contraction of the muscles of the lumbo-pelvic-hip complex (LPHC), also known as the core. In this example, the muscles of the core are all activating but no visible motion of the body is occurring. An isometric contraction can also be observed when an individual pauses during a resistance training exercise in between the lifting and lowering phases

Open-chain movements

distal limb moving freely in space i.e. lat pulldown is an open-chain exercise for the back musculature

During normal walking, the pelvis rotates in what plane to facilitate the necessary momentum for the swing phase?

idk this answer

What scientific term is used to describe the concept whereby a loaded eccentric contraction prepares the muscles for a rapid concentric contraction?

idk this answer

*Sagittal plane helpful hint

imagine being stuck in a very narrow hallway with no room to move to the left or right or to rotate. In addition, the walls are made completely of glass, which you don't want to break. Based on this analogy, the only available movements in our narrow sagittal plane hallway are front-to-back and up-and-down movements.

*Frontal plane helpful hint

imagine walls in front of and behind you, with no room to move forward or backward or to rotate. Like last time, the walls are made completely of glass, which you do not want to break. As a result, movements in the frontal plane are primarily side-to-side motions.

Isokinetic

isokinetic muscle actions, the muscle shortens at a constant speed over the full ROM. An isokinetic muscle action requires 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 speed remains constant.

Arthrokinematic

movement happening within a joint

Osteokinematic

movement that we observe

Concentric

muscle is exerting force greater than the resistive force, resulting in a shortening of the muscle. - The "lifting" phase during a resistance training - "Positive work" - the joint moves through a ROM against gravity - Expend the highest amount of energy compared to isometric and eccentric muscle action

force-couple

muscles that work in a synergistic function around a joint

What is optimal about the "optimal length" position?

optimal length is the position with maximal overlap of actin and myosin filaments.

What may happen when a muscle is in a shortened position or lengthening it beyond optimal length?

reduced force output

Agonist

the prime movers for a joint motion For example, the gluteus maximus is the agonist for hip extension the quadriceps are the agonists for knee extension, the anterior deltoid is the agonist for shoulder flexion, the biceps brachii is the agonist for elbow flexion, and the triceps brachii is the agonist for elbow extension

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

the regional interdependence model