ACE Ch 3 Applied Kinesiology

Third-Class Levers

(In Body) -In a third-class lever, the motive force has a short lever arm and the resistance has a long lever arm -Motive force muscles are at a mechanical disadvantage -Muscles typically attach near the joint, creating a short lever arm and, as a result, it requires relative high focus to lift even small weights -Application to training: Assuming a client is lifting the same amount of weight, he or she can create more resistance by moving the weight farther from the working joint, or less resistance by moving it closer to the working joint.

Hip Flexor Considerations- Tensor Fascia Latae

(TFL) -IT band -Explosive hip flexion results in highly developed TFL

Muscular Balance

-Achieving neutral spine requires muscular balance, which includes: -equal strength and flexibility on right and left sides of body -proportional strength ratios in opposing (agonist, antagonist) muscle groups (although they should not exactly equal) -Balance in flexibility (normal range of motion)

Posterior Hip Muscles- Hip Extensors

-Active range of motion for hip extension. -Prime movers: hamstrings (biceps, femoris, semitendinous, semimembranous) and gluteus maximus -Activated concentrically to extend the hip joint (e.g. prone leg lift) -Activated eccentrically to control hip flexion (e.g. downward phase or squat) -The Hamstrings work as prime movers during normal walking and low-intensity activity.

Lateral Hip Muscles- Hip External Rotators

-Active range of motion for hip external rotation -Prime movers: piriforms, superior gemellus, obturator internus, inferior gemellus, obturator externus and quadratus femoris.

Movements of the Scapula

-Anterior shoulder girdle muscles attach the scapulae to the front of the trunk -Posterior shoulder girdle muscles hold the scapulae to the back of the trunk

Torque

-For rotation to occur, the motive force must contract the lever at some distance from the axis of rotation. -Torque is the turning effect that occurs when the force acts on the lever arm -The pull of the biceps brachii on the radius creates a third-class level with axis or rotation at the elbow joint

Muscle Fiber Arrangements

-In addition to neurological training and recruitment, muscle fiber type, number, and arrangement influence a muscle's ability to create force -Muscle fiber arrangements include: --Penniform (unipennate, bipennate, multipennate) --Longitudinal

Plantarflexors considerations

-Inflexibility is common in the soleus and gastrocnemius (especially in those who frequently wear high-heeled shoes) -To stretch the gastrocnemius, the hip and knee should be extended and foot dorsiflexed; the heel should be touching the ground. -To isolate the soleus, flex the knee joint about 20 degrees.

Transverse Abdominis

-Involuntarily compress the viscera and supports the spine -Plays a vital role (with the multifidi) in providing feedback to the central nervous system about spinal joint position before dynamic forces in the extremities destabilize the spine -A sample exercise to activate the transverse abdominis involves lying on the floor with feet and knees flexed and visualizing pulling the naval inward toward the spine

Anterior Shoulder Girdle Muscles

-Major muscles include the pectoralis major and serratus anterior -The pectoralis major concentrically contracts to produce abduction, depression and downward rotation of the scapula -Enables powerful forward motion of the aim (overhead throw) -Sample exercises: supine punches and push-ups with a "plus"

Glenohumeral Joint Muscles

-Major muscles include the pectoralis major, deltoid, rotator cuff, latissimus dorsi and teres minor -The pectoralis major is divided into 3 sections based on their points of attachment: clavicular, sternal and costal -The clavicular portion concentrically contracts to flex the shoulder - As a whole, the pectoralis major is a prime mover in glenonumeral adduction, internal rotation, and horizontal flexion -Sample exercises include pectoral flys and pushups

Posterior Shoulder Girdle Muscles

-Major muscles include the trapezius, rhomboids and levator scapulae -The trapezius is divided into 3 sections (upper, middle and lower) that have different directions and lines of action of their fibers -Upper trapezius fibers are angled obliquely upward -Middle trapezius fibers are horizonta -Lower trapezius fibers are angled obliquely upward -Upward rotation involves concentric contraction of upper and middle trapezius, rhomboids and serratus anterior

Eccentric Contraction

-Muscle acts as the resistive force and lengthens as it creates tension. -External force exceeds the contractive force generated by the muscle. -Motion is controlled (slowed) by the muscle contraction

Hip Flexor Considerations- Illiopsas

-Muscle origins and insertions impact muscular function. -Illiopsas -The psoas major and minor originate in the low back and insert to the proximal femur, leading to poor mechanical leverage when used to raise and lower a straight leg. The abdominals are not strong enough to balance the large force and keep the spine in neutral alignment.

Isometric Contraction

-Muscle tension is created, but there is no apparent change in length -Resistance can come from opposing muscle groups, gravity, an immovable object, or weight training. -Motion is prevented by the muscle contraction (equal opposing forces)

Neutral Alignment

-Requires muscular balance -If a person is standing in the anatomical position, neutral alignment requires the line of gravity to pass through the center of the skull, the center of the vertebral column over the spinous processes, and the vertical crease between the buttocks, and the touch the ground between the feet. -Positioning of the pelvis affects the forces applied to the lumbar spine.

Exercises for the Trapezius

-Since each section of the trapezius controls a different motion, they have separate functions -Sample exercises for the trapezius:

External obliques

-Synergistic concentric contractions produce flexion -Unilateral concentric contractions produce lateral flexion -Combining lateral flexion with concentric action of the opposite oblique produces trunk rotation to the opposite side -Sample exercises include pelvic tilts, side-laying torso raises and straight and oblique reverse abdominal curls

The Middle Layer of Core Muscles

-The middle layer consists of the transverse abdominis, multifidi, quadratus lumborum, posterior fibers of the internal oblique, the diaphram and the pelvic floor muscles and fascia. -The outer layer consists of the rectus abdominis, erector spinae group, external and internal obliques and iliopsoas

Rhomboids

-The rhomboid major and minor work together as one unit -Concentric contraction produces adduction and elevation of the scapulae -Sample exercises include bent-over rows and ergometer rowing

Primary internal rotators

-There are no true primary internal rotators of the hip in the anatomical position. -As the hip is increasingly flexed to 90 degrees, the adductor longus and brevis, gluteus medius and maximus, pectineus and TFL become important in producing internal rotation.

Hip Flexor Considerations- Rectus Femoris

-Works at both the knee cap and hip, concentrically contracting to perform hip flexion and knee extension. -Sample strengthening exercise: standing straight-leg raise -sample stretching ex.: iliopsas lunge, bending the back knee

Motion

A change in an object's position in relation to another object.

Lever Classes

A lever is a rigid bar with a fixed point (fulcrum) around which it rotates when an external force is applied Lever Classes The body operates primarily as a series of third-class levers, with only a few first and second-class levers -Force (F) acts between the axis (x) and the resistance (R)

Sway back

A long outward curve of the thoracic spine with the accentuated lumbar curve and a backward shift of the upper trunk.

Agonist (or Prime Mover)

A muscle that causes a desired motion, while antagonists are muscles that have the potential to oppose the action of the agonist.

Curvilinear Motion

A small gliding motion within a joint (linear or transitory) combined with rotary motion of a segment.

Kyphosis

Abnormal and Fatigue-related posture. Excessive posterior curvature of the spine, typically seen in the thoracic region. -This posture is associated with "humpback", rounded shoulders, sunken chest and forward-head posture with neck hyperextension (possibly caused by tight pectoralis major and latissiumus dorse muscles and weak rhomboids and trapezius muscles) -Programming should focus on strengthening the weak muscles and strengthening the tight muscles -Commonly seen in older adults with osteoporosis.

Scoliosis

An excessive lateral curvature of the spine.

Rotary motion

An object is fixed and turns around a fixed point (angular motion)

Translatory Movement

An object is not fixed and moves in a straight line (linear)

Hip Flexors

Anterior Hip Muscles -Active range of motion for hip flexion -Prime movers: iliopsias, rectus femoris, Sartorius pectineus, and tensor fasciae latae -Acts synergistically to cause hip flexion (e.g. "up" phase of a knee lift) -Acts eccentrically to control hip-extension (e.g. "down" phase of a knee lift)

Dorsiflexors

Anterior Leg Muscles: -Prime movers: anterior compartment muscles (anterior tibialis, extensor digitorumlongus and extensor hallucislongus) -Act concentrically to dorsiflex the ankle -Act eccentrically during locomotor activities to lower the foot to the ground with control. -It is important to warm up the anterior compartment muscles before impact activity

Knee Extensors

Anterior knee muscles: -Primary movers: quadriceps femoris (I.e. vastus lateralis, vastus medialis, vastus intermedius, rector femoris) -Act concentrically when getting up from a chair or a squat -Act eccentrically when moving from standing to sitting -This allows knee flexion and a controlled movement -Strengthening exercises include squats and lunges -help for activities of daily living (ADL): walking, climbing stairs, lifting heavy objects -Safety recommendations: Do not flex knee past 90 degrees during weight bearing exercises

Synergist Muscles

Assist the agonist in causing a desired action

Motive Force

Causes an increase in speed or a change in direction

The outer layer of core muscles

Consists of the rectus abdominus, erector spinae group, external and internal obliques and iliopsoas

Co-contraction

Describes when the agonist and antagonist contract together and a joint must be stabilized

Lordosis

Excessively anterior curvature of the spine that typically occurs at the low back, but may also occur at the neck. -This posture is associated with low-back pain, large concentrations of abdominal fat, and an anterior pelvic tilt (possibly causing tight hip flexors and erector spinae and weak hip extensors and abdominals) -To correct the anterior pelvic tilt ex like: strengthen the abs and hip extensions (hamstrings). Stretch the hip flexors (iliopsoas) and spine extensors (erector spinae)

Forces

Force is a push or pull exerted by one object or another -External Force -Muscular Contractions Human movement is often described in terms of motive and resistive forces

Latissimus Dorsi and Teres Major

Glenohumeral Joint Muscles -The teres major is nicknamed the "little tat" -Both the latissimus dorsi and teres major concentrically contract to produce adduction, extension and internal rotation of the G/H joint. -Sample exercise: lat pull down (machine) -Note: This would not be the same ex. if using hand weights, as this notion would work the deltoids -Hand weights require exercises to be initiated in a direction opposite the pull of gravity

Rotator Cuff

Glenohumeral joint muscle -The rotator cuff consists of 4 muscles: the supraspinatus, infraspinatus, teres minor and subscrapularis -Remember the acronym SITS -Help stabilize the G/H joint against gravity. -Supraspinatus initiates abduction (prime mover through early ROM) -Infrasprinatus and teres minor are synergists for external rotation -Subscapularis is an internal rotator of the humerus -To prevent injury when working, the SITS muscles, the shoulders should be in neutral or external rotation when the arms are abducted or flexed

Hip Extensor Considerations-Gluteus Maximus

Gluteus maximus is a prime mover during higher-intensity activities such as stair climbing, sprinting and stationary cycling -Higher-intensity activities typically require greater hip ranges of motion and more powerful extension -Guideline for activities that involve the gluteus maximus: choose hip extension exercises that require at least 90 degrees of hip flexion at the start of the hip extension movement.

Line of Gravity

Gravity acts on the body in a straight line through its COG toward the center of earth

Core Training

In healthy individuals, the core's musculature functions reflexively to stabilize the spine under voluntary and involuntary loading without the need for conscious muscle control -Core muscle involvement is dynamic and effective. Core training must ultimately stimulate the patterns and planes of natural movement

Newton's 2nd Law

Law of Acceleration: Forces (F) acting on a body in a given direction is equal to the bodies mass (m) multiplied by its acceleration (a)

Newton's 1st Law

Law of Inertia: A body at rest will stay at rest and a body in motion will stay in motion (with the same direction and velocity) unless acted upon by an external force.

Newton's 3rd Law

Law of reaction: Every applied force is accompanied by an equal and opposite reaction,

Hip Flexor Considerations- Sartorius

Longest muscle in the body. It is also involved in hip abduction, adduction and external rotation. And external rotation, and knee flexion and internal rotation.

Hip Adductors

Medial hip muscles: primary adductors: adductor magnus, adductor longus and adductor brevis strengthening exercises: side lying leg lifts (lower leg) and supine hip adduction/abduction with the hips extended.

General Plane Motion

Motions at various joints are simultaneously linear and rotary

Concentric Contraction

Muscular Actions: -Muscular acts as the moving force and shortens as it creates tension. -Motion is CREATED by the muscular contraction

Newton's Laws of Motion

Newton's Laws of Motion describe the interrelationships among force, mass and human movement and are applied to either individual joints at the body as a whole.

Age-related Biomechanics

Older adult considerations -prevalence of musculoskeletal joint pain and alterations, sarcopenia, osteopenia, osteoporosis, osteoarthritis, decreased ROM, and loss of spinal flexibility "stopped" posture -Chair-seated exercise can be used when older adults have low self-confidence, fear of falling, or issues related to endurance and mobility. -Aquatic ex can improve performance of ADL, increase muscle stregth & flexibility, decrease body fat and improve self esteem

Kinetic Change Movement

Optimal performance of movement requires that the bodies muscles work together to produce force while simultaneously stabilizing the joints

Knee Flexors and Rotators

Posterior Knee Muscles -Prime movers: hamstrings (semitendinosus, semimembranosus and bicep femoris) -Secondary knee flexors include the sartorius, popliteus, gastroenemius, and gracilis -Knee rotation is only possible in flexed-joint positions -The semimembraneus and semitendinosus are internal rotators -The bicep femoris is an external rotator -Hamstring strengthening exercise: leg curl -To effectively stretch the hamstring, the targeted leg should be in hip flexion and knee extension, maintaining a neutral spine

Plantarflexors

Posterior leg muscles -prime movers: superficial posterior compartment muscles (soleus, gastrocnemius and plantaris) -The muscles of the deep posterior compartment and lateral tibial compartment aid in the propulsion force for human locomotion.

Flat Back

Posture -A decrease in the normal curvature of the lower back, with the pelvis in posterior tilt

Lateral Hip Muscles-Hip Abductors

Prime Movers: Gluteus medius, gluteus minimus, and superior fibers of gluteus maximus -Assisted by the TFL -Act concentrically to abduct the hip -Two-thirds of the gluteus maximus muscle fibers cross inferior to the joint axis, making them involved in hip abduction and adduction.

Trunk Flexors Abdominal Muscles

Prime movers: rectus abdominis, external obliques, internal obliques and transverse abdominus

Rectus Abdominis

Synergistic concentric contractions produce flexion -Eccentric contractions control extension -Unilateral concentric contractions produce lateral flexion. -Sample exercises include pelvic tilt, supine abdominal curls and abdominal crunches

Kenesiology of the Upper Extremity

Terminology Clarification: -Shoulder joint complex (four seperate upper-extremity segments) refers to the coordinated function of the: -Sternoclavicular (s/c) joint -Acromioclavicular (a/c) joint -Glenohumeral (g/h) joint -Scapulothoracic (s/t) articulation -Shoulder girdle is the formal term for the s/t articulation

Balance

The ability to maintain the body's position over its base of support within stability limits, both statistically and dynamically.

Core Stability

The body's "core" refers to the lumbar spine, pelvis and hips and all the muscles, tendons, ligaments and other connective tissue that create or limit the movement of these segments. -Core stability has been linked to successful gross motor skills and includes hip and trunk muscle strength, abdominal muscle endurance, ability to maintain a specific spinal or pelvic alignment and a sense of ligaments laxity. -Muscles of the core contribute to stability via intraabdominal pressure, spinal compressive forces and hip and trunk muscle stiffness (resistance to external loads)

Deep Layers of Core Muscle

The deep layer consists of the rotators, interspinali and intertransversarii)

Deltoid

The deltoid is divided into 3 sections, each with a diff fiber direction -The anterior deltoid flexes, internally rotates and horizontally flexes the arm -The middle deltoid concentrically contracts to produce abduction of the shoulder joint and eccentrically controls the return -The posterior deltoid extends, laterally rotates and horizontally extends the arm.

Closed Joint Movement

The end of the chain farthest from the body is fixed. This type of movement emphasizes stabilization through joint compression and muscle co-contraction.

Open-Chain Movement

The end of the chain farthest from the body is free. This type of movement involves more shearing forces at joints. -A joints mobility (range of uninhibited movement) should not be achieved by compromising joint stability.

Lateral leg muscles

The lateral leg muscles, the peroneus longus and brevis are the primary movers responsible for eversion of the foot. -Act concentrically to evert the foot -During locomotive activities, act eccentrically to prevent too much inversion of the subtalar joint, therefore preventing an ankle sprain.

Compartments of the lower leg

The lower leg is divided into four compartments: anterior tibial compartment, deep posterior compartment and superficial posterior compartment.

Medial Leg Muscles

The medial leg muscles, anterior tibialis and posterior tibialis are prime movers responsible for inversion of the foot. -Act concentrically to invert the foot -Both evertors and inventors are dynamic stabilizers of the ankle joint and medial arch of the foot

Center of Gravity (COG)

The point at which a bodies mass is considered to concentrate and where it is balanced on either side in all planes (frontal, sagital, transvers) -Also the point where gravity is enacting its constant downward pull.

Gravity and Muscular Actions

The primary muscles must contract concentrically to lift an object or create human movement that is in a direction opposite the pull of gravity. -The primary muscles must contract eccentrically to lower an object or control human movement that is in the same direction as the pull of gravity. -If gravity is eliminated (e.g. in movements being performed perpendicular to the pull of gravity [parallel to the floor]) each muscle group acts concentrically to produce the movement.

Base of Support

To maintain balance without moving, the line of gravity must fall within the base of support (BOS) -The BOS is the area beneath the body that is encompassed when one continuous line connects all points of the body that are in contact with the ground. - Balanced, neutral alignment requires that the body parts are equally distributed about the line of gravity within the BOS

Erector Spinae Group

Trunk Extensors -Prime movers: illiocostalis, longissimus and spinalis -Bilaterally and concentrically contract to produce extension and hyperextension -Eccentrically control flexion of the spine from a standing position (e.g. bending over the pick something off the floor) -Unilateral concentric contraction produces lateral flexion to the same side. -Sample exercises to strengthen these muscles include prone trunk hyperextension and the bird dog -Sample stretching exercises include the cat/camel

Internal Obliques

Trunk Flexors -Synergistic concentric produce flexion -Unilateral concentric action of the opposite oblique produces trunk rotation to the same side -Sample exercises include supine pelvic tilts, oblique abdominal curls and side-lying torso raises

Hip Abductor Considerations

When the hip is flexed more than 40 degrees, the six external rotators become the prime movers of hip abduction -Strength exercises: leg lifts lying down, butt raised clenches, elastic band pull away around feet.

Kinesiology

involves the study of human movement from biological and physical science perspectives. Understanding the principles and concepts of human movement provides the framework to analyze movement and design safe and effective programs for clients and class participants. Will help with: -Proper body mechanics -Neutral postural alignment -Muscular balance

Posture

refers to biochemical alignment of the individual body parts and the orientation of the body to the environment.

Resistive Force

resists the motion of another external force

Hip External Rotator Considerations

the external rotators -Horizontal muscle fibers -When the hip is in extension, the gluteus maximus functions as an external rotator. External rotator stretch: knee over leg lying down

Obesity-related Biomechanics

walking gait: obese individuals burn more calories during walking due to decreased efficiency, altered step frequency, greater vertical displacement of the COG and extraneus movements resulting in greater limb dimensions -Postural Balance: Anterior placement of the COG increases obese individuals risk of falling -walking gait continued: take force off knees and displace it on ankles -Increased risk for osteoarthritis: exercise programs should include cross training involving low-impact activities