Kines Unit 2

• Analysis of Movement -> stance, preparatory, movement, and follow through phases

  
• Stance Phase


  Allows for a comfortable and balanced body

  Emphasis on setting the various joint angles in their correct positions
• Stance Phase


  Allows for a comfortable and balanced body

  Emphasis on setting the various joint angles in their correct positions

  Static Phase

  
• Preparatory


  Most critical phase

  Becomes more dynamic as the need for explosiveness increases

  
• Movement Phase


  Acceleration Phase

  
• Follow Through Phase


  Begins immediately after the climax of the movement phase

  Brings about negative acceleration

  Deceleration phase

  
• Recovery Phase


  Used after the follow-through to regain balance and positioning to be ready for the next sport demand
• Open Kinetic Chain


  Any one link in the extremity may be moved individually without significantly affecting other links

  Distal end of the extremity is not fixed to a relatively stable surface

  Upper extremity ex -> shoulder shrug, deltoid raise/shoulder abduction, or bicep curl

  Lower extremity ex -> seated hip flexion, knee extension, and ankle dorsiflexion exercises

  
• Closed Kinetic Chain


  Distal end is fixed

  Movement of one joint cannot occur without causing predictable movements of other joints in the extremity

  Ex -> Push up, dip, squat, or dead lift

  
• Most sports involve closed-chained lower extremity activities and open-chain upper extremity activities
• Agonist Muscles 


  Cause joint motion through a specified plane of motion when contracting concentrically

  Prime Movers
• Assister or assistant movers


  Agonist muscles that contribute significantly less to the joint motion

  
• Antagonist Muscles


  Located on opposite side of joint from the agonist

  Eccentrically contract

  Known as contralateral muscles

  Works with agonist muscles to allow movement

  When contracting concentrically -> perform the opposite joint motion to agonist

  
• Stabilizers


  Surround joint

  Contract to stabilize the area to enable another limb or body segment to exert force and move

  Known as fixators

  Essential for establishing a relatively firm base for more distal joints to work

  
• Synergist


  Assist in the action of agonists

  Guiding muscle

  Rule out undesired movements

  
• Neutralizers


  Counteract and neutralize the action of another muscle to prevent undesirable movements

  ex -> when only the supination action of the biceps brachii is desired, the triceps brachii contracts to neutralize the flexion action of the bicep brachii
• Force Couples


  Occur when two or more forced are pulled in different directions on an object, causing the object to rotate about its axis

  Ex-> middle trapezius, lower trapezius, and serratus anterior each pull on the scapula from a different direction to produce the combined result of upward rotation

  
• Gait Analysis


  Functional evaluation of walking or running style
• Step


  a specific point in the gait on one extremity to the same point in the opposite extremity
• Step length


  Distance traveled between the initial contacts of the right and left foot
• Step width


  Distance between the points of contact of both feet
• Stride


  Two sequential steps
• Gait Velocity


  Meters per second
• Stride Time


  Time required to complete a single stride
• Stride length


  Linear distance covered in one stride
• Ground Reaction Force


  Contact of the foot with the ground created force yielding vertical, anteroposterior, and mediolateral components
• Center of Pressure


  Shows the path of the pressure point under the foot during gait
• Phases of Gait

  Stance phase (weight bearing) and Swing phase (non-weight bearing)
• What are the two points in which the body is supported on both legs?

  Midstance and Terminal stance
• Efficient gait


  Minimal side-to-side motion

  Maximal forward motion
• Stance Phase


  Begins on initial contact

  High-energy phase

  Kinetic energy is absorbed from the ground and transferred up the kinetic chain

  
• Swing phase


  Beings at the instant the foot leaves the surface and ends just before initial contact

  Low-energy phase

  
• Uniarticular Muscles


  Cross and act directly only on the joint that they cross

  Ex -> Brachialis -> can only pull the humerus and ulna closer together

  
• Biarticular Muscles


  Cross and act on two different joints

  Can cause and 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

  Ex -> Rectus Femoris -> is knee were to extend it would shorten and its ability to exert force would decrease, but its length and force production capability are maintained due to its lengthening at the hip joint during extension from a squat

  
• Active Insufficiency


  When the muscle becomes shortened to the point that it cannot generate or maintain active tension

  Muscle cannot shorten any further

  Ex -> rectus femoris contracting concentrically to both flex the hip and extend the knee but has to perform movements one at a time
• Passive Insufficiency


  When the opposing muscles becomes stretched to the point where it can no longer lengthen and allow movement

  Ex -> hamstrings cannot usually stretch enough to allow both maximal hip flexion and maximal knee extension at the same time
• Origin


  Proximal attachment of a muscle

  Functionally the least moveable part
• Insertion


  Distal attachment

  Functionally the most moveable
• 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 motion -> the angle of pull changes
• If the angle of pull is less than 90 degrees...


  The force is a stabilizing force because its pull directs the bone towards the joint axis