biomechanics (353)

what is biomechanics

study of forces and motion on and within biological systems

statics

study of systems in a state of equilibrium (at rest or moving with constant velocity)

dynamics

study of systems in a state of accelerated (ex:changing) motion

• kinematics and kinetics are a subfield

kinematics

description of motion without regard to the forces involved

ex: position, displacement, velocity, acceleration

kinetics

force, torque (more twisting), moment (more bending)

types of biomechanics applications

• sport biomechanics

• clinical & rehab biomechanics

• orthopedic biomechanics

• occupational biomechanics

• comparative biomechanics

sport biomechanics

improving technique, equipment, training, and injury prevention

clinical & rehab biomechanics

improve mobility & function

orthopedic biomechanics

research & design of artificial limbs, joints, and orthoses

occupational biomechanics

ergonomics & human factors

• productivity

• reduce workplace injuries

  • overuse: repetitive motions, chronic pains

  • overexertion: lifting, pushing, carrying

comparative biomechanics

movement in other living systems (ex: animals)

anatomical position

standing, legs together, arms/hands by the side, palms facing forward

reference system

relative: motion of a segment relative to an adjacent segment

absolute (global): motion of a segment with respect to a fixed frame or orientation

sagittal plane

• axis (direction): frontal (medial/lateral)

• motion: Flexion-extension

frontal plane

• axis (direction): sagittal (anterior/posterior)

• motion: abduction-adduction

transverse plane

• axis (direction): polar (longitudinal)

• motion: Internal-external rotation

arthrology

study of joint types & joint motion

degrees of freedom (DOF)

number of directions a segment can move in space

• 6: rotation & translation in the x,y, and z directions

• 3: rotation in the x, y, and z directions

  • for joint biomechanics we assume only rotation

directional terms

• distal - further from the trunk

• proximal - closer to the trunk

• medial - closer to midline

• lateral - further from midline

• anterior - front or forward-facing

• posterior - rear or rearward-facing

• superior - closer to the head

• inferior - further from the head

ipsilateral

same side of the body

contralateral

opposite side of the body

unilateral

one sided

bilateral

both sides ; ex: walking

joint motion terms

• flexion (decreasing the angle)

• extension (lengthening)

• adduction (towards)

• abduction (away)

• internal (medial) rotation

• external (lateral) rotation

ankle joint motion terms

• plantarflexion (downward)

• dorsiflexion (upward)

• inversion (inward)

• eversion (outward)

wrist joint motions

• flexion

• extension

• ulnar deviation (moves pinky side)

• radial deviation (moves thumb side)

forearm joint motions

• pronation (palm down)

• supination (palm up)

scapula joint motions

• protraction

• retraction

• anterior tilt

• posterior tilt

• upward rotation

• downward rotation

• elevation

• depression

head and trunk joint motions

• flexion

• extension

• right lateral flexion (bending)

• left lateral flexion (bending)

• right rotation

• left rotation