ES 346 Midterm Unit 2 Andre

Stance, Swing

Legs alternate between supportive (-) and nonsupportive (-)

Synergy, Opposing

Two muscles may work in - by counteracting their - actions to accomplish a common action

Stride

Two sequential steps

Analysis of Movement

Phase names vary from skill to skill to fit the various sports terminologies Names may vary depending upon the body part involved Major phases may also be divided even further Example: Baseball pitching in the preparatory phase is broken into early cocking and late cocking

Active Insufficiency

Reached when the muscle becomes shortened to the point that it cannot generate or maintain active tension The muscle cannot shorten any further

Passive Insufficiency

Reached when the opposing muscle becomes stretched to the point where it can no longer lengthen and allow movement

Preparatory Phase

Referred to as the cocking or wind-up phase Used to lengthen the appropriate muscles so that they will be in position to generate more force and momentum when they concentrically contract in the next phase Most critical phase in leading toward the desired result of the activity Becomes more dynamic as the need for explosiveness increases Right shoulder girdle is fully retracted in combination with abduction and maximum external rotation of the glenohumeral joint to complete this phase Pitcher begins the - phase by extending the throwing arm posteriorly and rotating the trunk to the right in conjunction with left hip flexion

Center of Pressure

Shows the path of the pressure point under the foot during gait

90, Advantageous, Strength

Sometimes, it is desirable to begin with the angle of pull at - degrees Chin-up or pull-up Angle makes the chin-up easier because of the more - angle of pull Compensate for the lack of sufficient -

Insertion

Structurally, the distal attachment or the part that attaches farthest from the midline or center of the body Functionally and historically, the most movable part is generally considered the -

Origin

Structurally, the proximal attachment of a muscle or the part that attaches closest to the midline or center of the body Functionally and historically, the least movable part or attachment of the muscle

Stabilizer Muscles

Surround the joint or body part Contract to fixate or - the area to enable another limb or body segment to exert force and move Also known as fixators Essential in establishing a relatively firm base for the more distal joints to work from when carrying out movements Example: Biceps curl Muscles of the scapula and the glenohumeral joint must contract in order to maintain the shoulder complex and humerus in a relatively static position so that the biceps brachii can more effectively perform curls The antagonists for each motion of the proximal joint co-contract or contract against each other to prevent motion This is an example of proximal - to enhance the effectiveness of distal joint motion, which occurs commonly with the upper extremity

Swing Phase

The non-weight-bearing phase of gait; begins at the instant the foot leaves the surface and ends just before initial contact. 38% of gait cycle Low-energy phase

Stance Phase

The weight-bearing phase of gait; begins on initial contact with the surface and ends when contact is broken. High-energy phase Kinetic energy is absorbed from the ground and transferred up the kinetic chain.

Stride Time

Time required to complete a single stride

Recovery Phase

Used after follow-through to regain balance and positioning to be ready for the next sport demand To a degree, muscles used eccentrically in the follow-through phase to decelerate the body or body segment will be used concentrically in - to bring about the initial return to a functional position Deceleration of the body and especially the arm is accomplished by high amounts of eccentric activity At this point, the - phase begins, enabling the player to reposition to field the batted ball

Rotary or Vertical, Stabilizing, and Dislocating

What are the components of the angle of pull?

Flight phase—neither foot is in contact with a supportive surface No period of double limb support Vertical GRF 2.0-6.0 x the body weight

What are the differences in running gait from walking gait?

The motor units activated Joint position at the time of contraction Planes of motion allowed in the joint Axis of rotation possible in the joint Muscle length Relative contraction or relaxation of other muscles acting on the joint

What are the factors that determine what action the muscle actually performs?

Initial Contact, Loading Response, Midstance, Terminal Stance, Preswing

What are the individual phases of the stance phase (weight-bearing)?

Initial Swing, Midswing, Terminal Swing

What are the individual phases of the swing phase (non-weight bearing)?

Stance, Preparatory, Movement, Follow-Through, and Recovery

What are the phases used in analysis of movement?

Can cause and or control motion at more than one joint Are able to maintain a relatively constant length due to shortening at one joint and lengthening at another joint

What are the two advantages biarticular muscles have over uniarticular muscles?

Weight Bearing (WB) Stance Phase Non-Weight Bearing (NWB) Swing Phase

What are the two distinct phases of the Gait Cycle?

Midstance and Terminal Stance

What are the two points that the body is supported by a single leg?

Easily observed in either biarticular muscles when the full range of motion is attempted in all the joints crossed by the muscle Example: Rectus femoris contracts concentrically to both flex the hip and extend the knee Can completely perform either action one at a time but actively insufficient to obtain the full range at both joints simultaneously, countercurrent movement pattern Similarly, hamstrings cannot usually stretch enough to allow both maximal hip flexion and maximal knee extension because of passive insufficiency As a result, it is virtually impossible to actively extend the knee fully when beginning with the hip fully flexed or vice versa

What is the example of active and passive insufficiency used and describe?

Closed Kinetic Chain

When the distal end of the extremity is fixed, as in a push-up, dip, squat, or dead lift, the extremity represents a - Movement of one joint cannot occur without causing predictable movements of other joints in the extremity Involves the body moving in relation to the relatively fixed distal segment Multiple joints are involved and numerous muscle groups must participate in causing and controlling multiple plane movements Very functional; Movements strongly correlate to most physical activities In determining appropriate conditioning exercises, consider an open versus - through an analysis of skilled movements Most sports involve - lower extremity activities and open-chain upper extremity activities

Swing, Less Than, Eccentrically, Swing, 10, 50, 55, 125, 40, 25, 20

- Phase of Running Gait Clears the NWB limb over the ground and positions the foot to accept WB. Probability of injury is - stance phase Hamstrings - contract to slow knee extension. - phase Hip: -° of extension to -° to -° of flexion Knee: Full extension to -° of flexion (sprinters) and to -° of flexion (preparing for contact) Ankle: -° of PF to -° of DF

Stance, 50, 30, 50, 25, Supinates, Pronates, Supinates

- Phase of Running Gait Hip: Flexed to -° and moves to extension Knee: Flexed to -°, moves to -° of flexion, and then moves into extension Ankle: DF to -° then moves to PF Subtalar: -, -, then - again

Step

A specific point in the gait on one extremity to the same point in the opposite extremity

107 +/- 2.7

Adults average = - steps per minute

Movement Without Contraction

Agonist Muscle Length: Dictated solely by gravity and/or external forces Antagonist Muscle Length: Dictated solely by gravity and/or external forces Joint Angle Changes: Dictated solely by gravity and/or external forces Direction of Body part: Consistent with gravity and/or other external forces Motion: Either no motion of passive motion as a result of gravity and/or other external forces Description: Passive, relaxation Applied Muscle Force vs. Resistance: No force, all resistance Speed Relative to Gravity or Applied Resistance Including Inertial Forces: Consistent with inertia of applied external forces or the speed of gravity Acceleration/Deceleration: Either zero or acceleration consistent with applied external forces Practical Application: Passive motion by force from gravity and/or other external forces

Eccentric Contraction

Agonist Muscle Length: Lengthening Antagonist Muscle Length: Shortening Joint Angle Changes: In direction of external force (resistance) Direction of Body part: With gravity and/or other external force (resistance) Motion: Controls motion Description: Dynamic lengthening; negative work Applied Muscle Force vs. Resistance: Force less than resistance Speed Relative to Gravity or Applied Resistance Including Inertial Forces: Slower than the speed of gravity or applied inertial forces Acceleration/Deceleration: Deceleration Practical Application: Slows down the rate of movement or stops movement, "braking action"

Isometric Contraction

Agonist Muscle Length: No appreciable change Antagonist Muscle Length: No appreciable change Joint Angle Changes: No appreciable change Direction of Body part: Against immovable object or matched external force (resistance) Motion: Prevents motion; pressure (force) applied, but no resulting motion Description: Static; fixating Applied Muscle Force vs. Resistance: Force 5 resistance Speed Relative to Gravity or Applied Resistance Including Inertial Forces: Equal to speed of applied resistance Acceleration/Deceleration: Zero acceleration Practical Application: Prevents external forces from causing movement

Concentric Contraction

Agonist Muscle Length: Shortening Antagonist Muscle Length: Lengthening Joint Angle Changes: In direction of applied muscular force Direction of Body part: Against gravity and/or other external force (resistance) Motion: Causes motion Description: Dynamic shortening; positive work Applied Muscle Force vs. Resistance: Force greater than resistance Speed Relative to Gravity or Applied Resistance Including Inertial Forces: Faster than the inertia of the resistance Acceleration/Deceleration: Acceleration Practical Application: Initiates movement or speeds up the rate of movement

Assisters of Assistant Movers

Agonist muscles that contribute significantly less to the joint motion

Stance Phase

Allows the athlete to assume a comfortable and balanced body position from which to initiate the sport skill Emphasis is on setting the various joint angles in their correct positions with respect to one another and to the sport surface Relatively static phase with fairly short ranges of motion - phase begins when the player assumes a position with the ball in the glove before receiving the signal from the catcher

Open Kinetic Chain

An extremity may be seen as representing an -if the distal end of the extremity is not fixed to a relatively stable surface Allows any one joint in the extremity to move or functionseparately without necessitating movement of other joints in the extremity Upper extremity examples include the shoulder shrug, deltoid raise or shoulder abduction, or a biceps curl Lower extremity examples include seated hip flexion, knee extension, and ankle dorsiflexion exercises In these exercises the core of the body and the proximal segment are stabilized while the distal segment is free to move in space through a single plane Beneficial in isolating a particular joint to concentrate on specific muscle groups Not very functional as they involve mostly physical activity, particularly for the lower extremity, that requires multiple joint activity involving numerous muscle groups simultaneously

Phases, 3, 5, Preparatory, Movement, Follow-Through, Stance, Recovery

Analysing various exercises and sport skills Break down all movements into - Number of phases varies, usually - to - All sport skills will have at least -, -, and - phases Many begin with a - phase and end with a - phase

Angle of Pull

Angle between the line of pull of the muscle and the bone on which it inserts, which is the angle toward the joint With every degree of joint motion, the - changes Joint movements and insertion angles involve mostly small -

Opposite, Antagonistic, Extension, Concentrically, Eccentric

Antagonistic muscles produce actions - to those of the agonist Example: Elbow extensors are - to elbow flexors Return movement to the hanging position at the elbow joint after chinning is elbow joint -, but the triceps and anconeus are not being strengthened Elbow joint flexors contract - followed by - contraction of the same muscles

Shortens, Diminishes

As a muscle -, its ability to exert force -

Arm swing Stride length Cadence Knee flexion ROM Muscular force Speed of contraction Less up and down motion

As speed during the gait increases, what changes?

Synergist Muscles

Assist in the action of agonists Not necessarily prime movers for the action Known as guiding muscles Assist in refined movement and rule out undesired motions They may be helping -

Follow-Through Phase

Begins immediately after theclimax of the movement phase Brings about negative acceleration of the involved limb or body segment Often referred to as the deceleration phase Generally, the greater the acceleration in the movement phase, the greater the length and the importance of the - phase Some athletes may begin- too soon, which: Inappropriately cuts short the movement phase Has a less-than-desirable result in the activity Deceleration of the body and especially the arm is accomplished by high amounts of eccentric activity

Agonist (Primary or Prime Mover) Muscles

Cause joint motion through a specified plane of motion when contracting concentrically Known as - or -, or as muscles most involved Some - muscles, because of their relative location, size, length, or force generation capacity, are able to contribute significantly more to the joint movement than other -

Rotary or Vertical Component

Component of muscular force that acts perpendicular to the long axis of the bone or lever When the line of muscular force is at 90 degrees to the bone on which it attaches, all of the muscular force is - force, that is, 100 percent of the force is contributing to movement All of the force is being used to rotate the lever about its axis The closer the angle of pull to 90 degrees, the greater the - component

Ground Reaction Force

Contact of the foot with the ground creates force yielding vertical, anteroposterior (A/P), and mediolateral (M/L) components

Neutralizers

Counteract or - the action of another muscle to prevent undesirable movements such as inappropriate muscle substitutions, which is referred to as - Contract to resist specific actions of other muscles Example 1: When only the supination action of the biceps brachii is desired, the triceps brachii contracts to - the flexion action of the biceps brachii Example 2: Biceps curl: When only the flexion force of the biceps brachii is desired, the pronator teres contracts to - the supination component of biceps

Uniarticular Muscles

Cross and act directly only on the joint that they cross Example: Brachialis, which can only pull the humerus and ulna closer together

Biarticular Muscles

Cross and act on two different joints Depending on certain factors, - muscles may contract and cause motion at either one or both of its joints Two advantages over uniarticular muscles: Can cause and or control motion at more than one joint Are able to maintain a relatively constant length due to shortening at one joint and lengthening at another joint Muscle does not actually shorten at one joint and lengthen at the other Concentric shortening of the muscle to move one joint is offset by the motion of the other joint, which moves its attachment of the muscle farther away This maintenance of a relatively constant length results in the muscle being able to continue its exertion of force Example 1: Hip and knee - muscles Concurrent movement pattern occurs when both the knee and hip extend at the same time If only the knee were to extend, the rectus femoris would shorten and its ability to exert force similar to the other quadriceps muscles would decrease, but its relative length and subsequent force production capability are maintained due to its relative lengthening at the hip joint during extension

Minimal side-to-side motion Maximal forward motion Body rises and falls approx. 5 cm Center of gravity Path is a sinusoidal curve.

Describe Efficient Gait

Closed Chain Exercise

Distal end of extremity: Fixed to something Movement pattern: Characterized by linear stress in the joint (functional) Joint movements: Multiple occur simultaneously Muscle recruitment: Multiple (significant muscular co-contraction) Joint axis: Primarily transverse Movement plane: Multiple (triplanar) Proximal segment of joint: Mobile Distal segment of joint: Mobile, except for most distal aspect Motion occurs: Proximal and distal to instantaneous axis of rotation Functionality: Functional Joint forces: Compressive Joint stability: Increased due to compressive forces Stabilization: Not artificial, rather realistic and functional Loading: Physiological, provides for normal proprioceptive and kinesthetic feedback

Open Chain Exercise

Distal end of extremity: Free in space and not fixed Movement pattern: Characterized by rotary stress in the joint (often nonfunctional) Joint movements: Occur in isolation Muscle recruitment: Isolated (minimal muscular co-contraction) Joint axis: Stable during movement patterns Movement plane: Usually single Proximal segment of joint: Stable Distal segment of joint: Mobile Motion occurs: Distal to instantaneous axis of rotation Functionality: Often nonfunctional, especially lower extremity Joint forces: Shear Joint stability: Decreased due to shear and distractive forces Stabilization: Artificial Loading: Artificial

Step Width

Distance between the points of contact of both feet

Velocity

Distance covered per unit time (i.e., m/sec)

Step Length

Distance traveled between the initial contacts of the right and left foot

Agonist, Antagonist, Synergistic, Synergistic, Stabilize, Neutralized

Ex. of Kicking Ball Muscles primarily responsible for hip flexion and knee extension are - Hamstrings are - and relax to allow the kick to occur Preciseness of the kick depends on the involvement of many other muscles The lower extremity route and subsequent angle at the point of contact, during the forward swing, depend on a certain amount of relative contraction or relaxation in the hip abductors, adductors, internal rotators, and external rotators, acting in a - fashion to guide lower extremity precisely These - muscles in contralateral hip and pelvic area must be under relative tension to help fixate or - the pelvis on that side in order to provide a relatively stable base for the hip flexors on the involved side to contract against Abduction and adduction actions are - by each other Common action of the two muscles results in hip flexion

Origin, Insertion, Reversed

Example: Biceps curl exercise Biceps brachii muscle in the arm has its - on the scapula and its - on the radius In some movements this process can be - Example: Pull-up Radius is relatively stable and the scapula moves up

Helping Synergists

Have an action in common but also have actions antagonistic to each other Help another muscle move the joint in the desired manner and simultaneously prevent undesired actions Example: Anterior and posterior deltoid Anterior deltoid acts as an agonist in glenohumeral flexion, while the posterior deltoid acts as an extensor Helping each other, they work in - with the middle deltoid to accomplish abduction

Dislocating Component

If angle is greater than 90 degrees, the force is - because its pull directs the bone away from the joint axis

Stabilizing Component

If the angle is less than 90 degrees, the force is a - force because its pull directs the bone toward the joint axis

Movement Phase

Known as the acceleration, action, motion, or contact phase Is the action part of the skill Summation of force is generated directly to the ball, sport object, or opponent Usually characterized by near-maximal concentric activity in the involved muscles

Stride Length

Linear distance covered in one stride

Antagonist Muscles

Located on the opposite side of joint from the agonist Have the opposite concentric action Known as contralateral muscles Work in cooperation with agonist muscles by relaxing and allowing movement When contracting concentrically, they perform the joint motion opposite to that of the agonist Example: Quadriceps muscles are - to hamstrings in knee flexion

Gait Velocity

Meters per second

Agonist, All, Contracting, Cannot

Muscles with multiple - actions: Attempt to perform - of their actions when - - determine which actions are appropriate for the task at hand

Cadence

Number of steps taken per unit time (i.e., steps per minute)

Force Couple Muscles

Occur when two or more - are pulling in different directions on an object, causing the object to rotate about its axis - of muscular - together in the body can result in a more efficient movement Example: Middle trapezius, lower trapezius, and serratus anterior each pull on the scapula from a different direction to produce the combined result of upward rotation

The Kinetic Chain Concept

Our extremities consist of several bony segments linked by a series of joints Bony segments and their linkage system of joints may be likened to a - Any one link in the extremity may be moved individually without significantly affecting other links if the - is open or not attached at one end If the - is securely attached or closed, substantial movement of any one link cannot occur without substantial and subsequent movement of the other links