L31 - Functional Anatomy for ExRx

• Anatomical position:

  • Refers to body orientation to describe someone's anatomy (no matter what position body is in)
  • Anatomy position = standing upright
  • Important for clear consist way of describing movement
  • Provides a reference point
  • Functional anatomy:
  • Posterior/dorsal
  • Proximal & distal - how close to body
  • 5 Regions:
  • 1) Head
  • 2) Torso/trunk + chest
  • 3) Upper extremities
  • 4) Pelvis
  • 5) Lower extremities
  • 3 planes:
  • Sagittal (left & right)
  • Coronal (front & back)
  • Transverse (top & bottom)
  • Sections to describe functional anatomy
• Joints:

  • Approx 360 joints in the human skeleton
  • 3 main categories (change depending ons structure & function):

  1. Fibrous - synarthrosis
  2. No movement (eg skull)
  3. Cartilaginous - symphysis (fibrocartilage) & synchondroses (hyaline cartilage)
  4. Little bit of movement (eg in spine + pubic symphysis)
  5. Synovial - most movable & most complex
  6. Lots of movement
• Synovial joints:

  • Different types
  • Bones separated by synovial cavity, which contains synovial fluid (for frictionless movement)
  • Articulating surfaces covered with cartilage
  • Fibrous capsule encloses the cavity
  • Ligaments - join bone to bone
  • Of collagen & elastin; slightly more elastic than tendons
  • More elastin in pregnancy = causes problem
  • Tendons - join muscle to bone
  • Less elastic than ligaments
• Synovial Joint Types:

  • Pivot joint
  • bw/ vertebrae
  • Atlas & axis join in top of spine (to shake head)
  • Hinge joint
  • bw/ humerus + ulna
  • Movement in 1 axis
  • Flexion & extension
  • Saddle joint
  • bw/ metacarpal + carpal
  • Flexion, extension + rotation
  • Ball & socket joint
  • bw/ hip & femur
  • Multi-axis for all movements
  • Condyloid joint
  • bw/ metacarpal + phalanx
  • Kind of ball & socket
  • Usually flexion, extension, abduction & adduction
  • More flat
  • Plane joint
  • bw/ tarsals
  • Similar movement as above
  • Majority of joints in feet & hand not used very often
• Muscles:

  • 3 types of muscle tissue (skeletal, smooth & cardiac muscle)
  • Differ in cell structure, location & innervation
  • Smooth = involuntary, in organs & blood vessels
  • Cardiac = involuntary, in walls of heart
  • Skeletal = voluntary, can be controlled for movement (some involuntary such as diaphragm)
  • About 700 muscles contribute to the musculoskeletal system
  • Muscle comprises ~40% of body weight
  • 75% water, 20% protein, 5% organic & inorganic compounds
  • 32% of all energy protein stores in muscle
• Skeletal muscle:

  • Maintain posture & stabilise joints
  • Important for prescribing stability
  • Generate lot of heat as a byproduct
  • Fascia = 3 part connective tissue framework
  • Epimysium - outermost layer
  • Perimysium - subdivides muscle fibres into fascicles
  • Each fascicle comprised of a bundle of muscle fibres
  • Endomysium - surrounds the muscle fibre
  • Muscle fibres contain bundles of myofilaments
• Skeletal muscle:

  • Muscle has an origin point & insertion (distal attachment)
  • When tendon attaches to bone that is moving = origin
  • No muscle move by themselves (has agonist [shortening/contracting], & antagonist [lengthening/relaxing])
• Muscle contractions:

  • Concentric = muscle shortening
  • Eccentric = muscle lengthening
  • Isometric = static
  • Max force at optimal position (certain degree)
• Muscle fibre direction matters!

  • 1 most important thing in ExRx
  • Parallel= most muscles in same direction from origin to insertion
  • Where force more important than length, not in single line but are pennate (at different angles in different ways)
  • Unipennate
  • Bipennate
  • Multipennate
  • Pennate pulls at an angle
  • Pennate often shorter, therefore can generate more force
• Different movements:

  • Flexion
  • Decrease angle bw/ 2 body parts
  • Extension
  • Increase angle
  • Abduction
  • Away from midline
  • Adduction
  • Towards midline
  • Medial rotation
  • Rotation towards midline
  • Lateral rotation
  • Rotation towards outside/laterally
• Example: The shoulder

  • Ball & socket joint = multiaxial
  • More mobile but decrease stability
  • Easy to dislocate
  • Shoulder muscles contribute to stability of joint
  • If shoulder stability something need to train then don’t focus on one single muscle
  • Also consider effects of gravity & resistance
  • Adduction against gravity (abductors one mainly focusing on movement, are contracting eccentrically) vs against resistance (adductor muscles contract, shorten - concentric)
• Deltoid:

  • Triangular muscle with 3 parts:
  • Anterior, middle (multipennate), posterior
  • Multipennate produce most of force (medial, anterior run oblique in uninterrupted manner onto shaft of humerus)
  • Anterior = flexor + medial rotator
  • Lateral/Middle = abduction
  • Posterior = extensor + lateral rotator
• Gluteus maximus

  • Important for hip stability
• Function vs Sport vs Weight-lifting:

  • Functional movements are movements based on real world situational biomechanics → multi-planar, multi-joint movements
  • Functional movements attempt to incorporate as many variables as possible (balance etc)
  • Therefore decreasing the load on the muscle, but increasing the complexity of motor coordination & flexibility
  • Functional based on real life situations (multi-planar + multi-joint)
• Function vs Sport vs Weight-lifting:

  • Sport specific movements, such as a tennis swing are based on sport specific situations
  • There is some crossover with functional movements, but they are usually so specific that they are more complex compared to functional movements
• Function vs Sport vs Weight-lifting:

  • Weight-lifting movements, such as biceps curl, tend to be the most far removed from functional movements due to their attempt to micromanage variables acting on the individual muscles
  • Bicep curl = very specific (not functional)
  • Not to say guidelines are wrong, but when looking at general population weightlifting vs sport specific not important (is for athletes)