Biomechanics Flashcards
Biomechanics
How internal/external forces affect the human body and performance
Kinetics
Muscles pulling on bones, bone on bone, inside joints (internal forces)
Kinematics
Time, displacement, velocity, acceleration
3 models of human motion
Particle model, stick figure, rigid body segment
Particle model
Dot represents centre of mass, used when body/object is airborne
Stick figure model
Body segments are “sticks”, used when the body is in contact with other objects (used to describe gross motor skills in 2D)
Rigid body segment
Each body segment is represented as an irregularly shaped 3D volume (used for computer analysis)
Newton’s first law
Every body remains in a state of rest or uniform motion unless it’s acted on by an external unbalanced force
Newton’s second law
The acceleration of an object is directly proportional to the force acting on it and inversely proportional to its mass
Newton’s third law
For every action there is an equal and opposite reaction
Stability (1)
Lower the centre of gravity (larger base of support). The closer the centre of mass to the midline of the base of support, greater mass, stability increases
Maximum effort (2)
The production of maximum force requires the use of all possible joint movement that contributes to the tasks objective
Maximum velocity (3)
The production of maximum velocity requires the use of joints in order (largest-smallest)
Linear motion (4)
The greater the applied impulse, the greater the increase in velocity
Linear motion (5)
Movement usually occurs in the direction opposite of the applied force
