final 2

• Types of motions and examples


  • Translatory motion (linear) (not fixed at an axis): travel the same distance, same direction, same velocity
  • Example: 100yd dash
  • Curvilinear (not fixed to an axis): objects on a curved path
  • Example: kicking a ball
  • Rotary motion (angular) (fixed to an axis): in a circle around an axis, different velocities (the further from the axis, greater the velocity)
  • Example: an ice skater spinning around, or bending of arm
• Types of joints and examples

  • Synarthrodial joints: immovable/slightly moveable joints, no degrees of freedom
  • Synarthrodial suture: fibrous structure of where our skulls come together
  • Syndesmosis: fibrous structure of where between tibia and fibula and between ulna and radius
  • Amphiarthrodial joints: limited moveable joints, no degrees of freedom
  • Symphysis pubis
  • Intervertebral discs
  • 1st sternocostal joint
  • Diarthrodial joints: freely moveable, has a joint capsule, articular discs
  • Nonaxial: gliding joint, no axis of movement. Intercarpal joints of the write and intertarsal joints of the foot
  • Uniaxial: Hinge joint, one axis of rotation (movement in one plane). Elbow, Ankle, interphalangeal joint
  • Pivot/Screw joint: one axis of rotation, rotational movement. Atlantoaxial joint (helps us shake out head no) proximal radioulnar joint (helps pronation and supination of elbow)
  • Biaxial: two axes of movement, two degrees of freedom
  • Ellipsoid joint, radiocarpal joints of wrist: flexion and extension, ulnar deviation
  • Condyloid joints: movement in two planes without rotation. Metacarpophalangeal joints of the hands, flexing and extending, abduction and adduction
  • Saddle joint: movement in two planes, only in the 1st carpometacarpal joint of the thumb
  • Triaxial: multiple axes allowing multiple planes of movement, three degrees of freedom. Ball and socket joints: hip, and glenohumeral joint
• Planes and axes and examples

  • Frontal Plane: divides out body from the front to back (medial and lateral)
  • Example: flexion and extension
  • X-axis
  • Sagittal Plane: divides the body into left and right (anterior and posterior)
  • Example: abduction and adduction
  • Z- axis
  • Transverse plane: divides the body into lower and upper (superior and inferior)
  • Example: rotation
  • Y- axis
• Newton's Laws


  • Law of inertia: a body at rest stays at rest, a body in motion stays in motion, until acted upon by an outside force
  • Inertia: what must be overcome to cause or stop motion, how much resistance it has to stop moving
  • Law of acceleration: change in acceleration of a body occurs in the same direction as the force. Change in acceleration is directly proportional to the force causing it and inversely proportional to body mass
  • Law of reaction: for every action there is an equal and opposite reaction
  • Ground reaction force: hit the ground with 100 pounds of foot, the ground is hitting you with 100 pounds
• Class of levers and examples


  • 1st class lever: axis between and force resistance
  • Example: atlanto-occipital joint, seesaw (head rests on neck)
  • 2nd class lever: resistance between axis and force
  • Example: wheel barrel, force: us picking up, axis: wheel. Strongest lever
  • Muscle is outside, resistance is in the middle
  • 3rd class lever: forces between axis and resistance
  • Example: bicep curl, muscle is between axis and resistance
• Mass


  Measurement of how much matter an object contains
• Weight


  Measurement of the gravitational force on an object
• How can balance be improved

  • Greater weight more balance
  • Widen base in direction of force
  • Keep moving
  • Increase friction
  • Keep COG within base of support (object that's in contact with the ground)
  • Larger base of support
• Afferent vs efferent nerve


  • Afferent: nerve impulses that send signals to the brain (sensory)
  • Efferent: nerve impulses that send signals from the brain to the muscles (motor)
  • A alpha and A beta: sensory fibers (larger and faster)
  • A gama: motor fibers
  • A delta C fibers: pain, smaller and slower
• Muscle tissue properties


  • Excitability: responsiveness to stimulation
  • Contractility: make shorter
  • Extensibility: ability to be stretched
  • Elasticity: ability to stretch and return to original
• Stress


  Force that the body resists
• Strain


  Amount of deformation the body can tolerate before succumbing to the stress
• Regions of stress-strain curve


  • Toe Region: 1.5-4% of total lengthening of tissue (straightening fibers but it is not being strained)
  • Elastic region: 2-5% of elongation, fibers are being strained but it goes back to normal length
  • Plastic region: 5-10%, stretches beyond limit, permanently longer
  • Failure: 6-10%, rupture
• Agonist vs Antagonist vs Synergist


  • Agonist: muscles that contribute to a given motion (prime mover)
  • Antagonist: muscles that work in the opposite of muscle contraction
  • Synergist: muscle that helps facilitate action
• As velocity of contraction increases


  Force production decreases
• As velocity of contraction increases


  Force production increases
• Open vs closed chain exercises


  • Open kinetic chain (OKC): distal segment is moving freely
  • Examples: bicep curl, bench press
  • Closed kinetic chain (CKC): distal segment is fixed, position does not change
  • Examples: push up, squats
• Factors that influence muscle force production


  • Muscle size: length (speed), width (force), longer (faster) vs. shorter (has a greater amount of force)
  • Fiber architecture: basic microanatomy, muscle fibers (more fibers, more force)
  • Passive components of the muscle (cannot contract)
  • Facia: cannot contract (passive elastic component, parallel elastic component: how fibers are oriented)
  • Length tension relationship
  • Tissue failure occurs at the point where the muscle is not getting lengthened or shortened
  • Resting length: no tension within the muscle, where it can produce most force
  • Moment arm: line of muscle pull changes with different positions, perpendicular to the muscle. The longer the moment arm the greater torque. As the moment arm increases, force production increases. As the moment arm decreases, force production decreases
  • Speed of muscle contraction: Concentric: inverse relationship, Eccentric: somewhat proportional
  • Active tension: force produced by muscle is determined by the number of motor units and firing rate. More motor units produced more force
  • Age and sex: Peak 20-30 years
• Differences between the types of contractions


  • Isometric contraction: muscle is held at a fixed length, Tendon lengthens leads to muscle fibers shortening, Overall length of musculotendinous is constant
  • Isokinetic: same velocity throughout the contraction
  • Isotonic contraction: same tension
  • Concentric contraction: consists of shortening and eccentric contractions. Shortening: force generated < maximal capability of muscle contraction, Eccentric: lengthening *letting back down*, generates more force
• Scapular motion


  • Elevation: body of scapular goes superior
  • Depression: body of scapula goes inferior
  • Protraction: scapula goes anterior around the ribcage
  • Retraction: scapula back toward midline/spline
  • Upward rotation: inferior: far away from midline, superior: close to midline/spine
  • Downward rotation: superior: far from midline, inferior: close to midline
• Contributions to scapular tipping and winging (what is tight vs weak)


  • Scapular winging: the midline borders of the scapula come away from the thoracic wall wall
  • Scapular tipping: inferior angle of the scapula comes away from the thoracic wall
  • Tight muscles: levator scapulae, upper trapezius, pectoralis minor, leads to tipping
  • Weak muscles: rhomboids, lower middle trap, serratus anterior
• Anatomical snuffbox


  Contents: Scaphoid bone, Radial border: extensor pollicis brevis, abd PL tendon, Ulnar border: extensor pollicis longus tendon, Commonly fractured, Poor blood supply
• Joints of the Shoulder


  • True Joints: Sternoclavicular, Acromioclavicular, Glenohumeral
  • Functional Joints: Scapulothoracic, Coracoacromial
• Motions of the Sternoclavicular Joint


  • Elevation (going up), Depression (going down), Protatrion: going anterior, Retraction: going posterior
• Joints of the Elbow


  • Humeroulnar: hinge joint, one degree of freedom, flexion and extension
  • Humeroradial: flexion, pronation/supination
  • Proximal radioulnar: one degree of freedom, pronation/supination
• Joints of the wrist and hand


  • Distal radioulnar Joint: motions are pronation/supination
  • Radiocarpal Joint: motions are flexion/extension and radial/ulnar deviation
  • Midcarpal Joints: gliding joints between carpal joints
  • Carpometacarpal Joints
  • 1st Carpometacarpal Joint: saddle joint, flexion/extension, abduction/adduction
  • 1-5 Metacarpophalangeal Joints: flexion/extension, abduction/adduction. Ulnar collateral ligament: valgus force, radial collateral ligament: varus force
  • Interphalangeal Joints: hinge joints, flexion and extension only
• Innervation of hypothenar eminence


  Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, Innervated by the ulnar nerve
• Innervation of the thenar eminence


  Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, adductor pollicis, Innervated by the median nerve
• Wrist flexors (anterior)


  • Innervated by the median nerve *except for the FCU*
  • Flexor carpi ulnaris: only anterior muscle innervated by the ulnar nerve
• Wrist extensors (posterior)


  • Innervated by the radial nerve
• Prominent muscles of the shoulder, elbow, forearm (posterior vs anterior), wrist and hand


  • Pectoralis Minor: Action: anterior tilt of the scapula, Innervation: medial pectoral
  • Rotator Cuff: Supraspinatus: action: abduction, innervation: suprascapular, Infraspinatus: action: lateral rotation, innervation: suprascapular, Teres minor: action: lateral rotation, innervation: axillary, Subscapularis: action: medial rotation, innervation: subscapular
  • Teres Major: Action: extension, adduction, medial rotation, Innervation: subscapular
  • Deltoid: Action: anterior flexion, abduction, extension, Innervation: axillary
  • Triceps Brachii: Action: shoulder extension, elbow extension, Innervation: radial
  • Elbow flexors: Biceps Brachii
• Prominent muscles of the hand


  • Abductor pollicis brevis
  • Flexor pollicis brevis
  • Opponens pollicis
  • Adductor pollicis
• Innervated by


  Median nerve
• Wrist flexors (anterior)


  • Innervated by the median nerve *except for the FCU*
  • Flexor carpi ulnaris: only anterior muscle innervated by the ulnar nerve
• Wrist extensors (posterior)


  • Innervated by the radial nerve
• Nerve supply:
• Prominent muscles of the shoulder


  • Pectoralis Minor
  • Rotator Cuff
• Pectoralis Minor


  • Action: anterior tilt of the scapula
  • Innervation: medial pectoral
• Rotator Cuff


  • Supraspinatus: action: abduction, innervation: suprascapular
  • Infraspinatus: action: lateral rotation, innervation: suprascapular
  • Teres minor: action: lateral rotation, innervation: axillary
  • Subscapularis: action: medial rotation, innervation: subscapular
• Teres Major


  • Action: extension, adduction, medial rotation
  • Innervation: subscapular