Concepts of Movement and Biomechanics Flashcards
What is kinesiology?
- Study of human movement
- Combines 3 other sciences into one: Anatomy, physiology and biomechanics
What are statics?
- Deals with aspects of non moving systems (quiet stance)
- Encompases active stability
- Static body position: supported by a solid stance that can withstand sustained pressure
What are dynamics?
- Deals with aspects of moving systems
- Focuses on a dynamic body, where one changes shape relatively quick and how various forces affect it
- Divided into kinetics and kinematics
What are kinetics?
- Studies forces (such as gravity, friction and pressure) that act on the body to generate or alter motion
- A kinetics perspective, slipping on a banana peel would encompass how little friction there was between the peel and the floor and how gravity laid you out
What are kinematics?
- Involves the analysis of movement in terms of mechanical elements (such as time and space)
- A kinematics perspective, slipping on a banana peel would be concerned with how fast you were walking when you slipped, and how far your center of gravity fell
What are the 4 ballerinas of human movement?
- Mobility, stability, balance and coordination
What is mobility?
- The ability to move
- Obvious and expressive aspect of motion that recieves much attention
What is stability?
- Comes before mobility, since it provides the necessary and sometimes oppositional support for mobility
- The silent partner of motion
- The ability to be firmly fixed or supported
- Found in both dynamic and static movement
- Uses an ever-changing contingent of joints and the myofascial units
What is balance?
- The even distribution of weight that enables you to remain upright and steady
- An attribute that you innately seek in many aspects of your life, not only in the body
- Being unbalanced isn’t unwelcomed because without imbalance some movements wouldn’t be possible
- Walking down the street demands oscillating between stability and instability
What is coordination?
- The organization of different elements
- Nerves, joints and muscles all work together
- The only way to make balancing look easy
What is simultaneous movement?
- When the entire body moves at the same time, simultaneously
- Launching yourself off a ramp when skateboarding is an example of this
What is sequential movement?
- When a movement occurs through a series of smaller, articulating actions
- Rising up from sitting on the ground would be an example of this
What are movement patterns?
- These patterns are organized rhythms of motion that link groups of joints and muscles together to produce a desired action
- Making your bed would be an example of this, since you perform the same steps and process everyday
What are kinetic chains?
- A movement patterns predictable sequences
- The series of joints linked by an arrangement of muscles and bones along the pathway of movement
- There are 3 types of kinetic chains: articular (joints), myofascial (muscles and fascia) and neural (nerves)
- These 3 chains work together to create action in the body
What does proportioned mean?
- Corresponding in size to something else
What does symmetrical mean?
- Composed of exactly similar parts facing each other
What is compensation?
- What the body does to cope when its not proportioned or symmetrical
- It uses the nervous system to exert an opposite effect with the muscles, fascia and joints
What are extrinsic factors?
- Where human movement (task is a major function) is determined by force, distance or gravity
- Outer factors
What are intrinsic factors?
- How body segments align to allow or limit movement potential and performance
- Inner factors
What does valgus mean?
- Outward angle of a distal segment (lateral)
What does varus mean?
- Inward angle of a distal segment (medial)
What does contralateral mean?
- Relating to the opposing sides of the body (right are is contralateral to left leg)
What does bilateral mean?
- Relating to the right and left sides of the body (right arm is bilateral to right leg)
What is regional interdependence?
- All systems are required for efficient human movement
What is kinesthetic awareness?
- Person’s ability to know where his/her body is in space without looking (influenced by movement patterns and habitual posture)
What is the 1st law of motion?
- Known as inertia
- A body in motion stays in motion at the same speed in a straight line
What is the 2nd law of motion?
- Known as the acceleration that occurs when there is applied force
- Force: mass X acceleration
What is the 3rd law of motion?
- Known as the law of reaction
- For every action there is an equal and opposite reaction
- Ground reaction force is the force exerted by the ground when the body contacts it
What is friction?
- The force between 2 surfaces and the force which opposes the motion of the object
- Static, sliding and rolling
What is rectilinear movement?
- A linear motion in which the direction of the velocity remains constant
- Path of the movement stays in a straight line
What is curvilinear movement?
- A motion in which the direction of the velocity of a body is variable
- Path of movement is in a curved line
What is rotational movement?
- When every particle in the body moves in a circle about a single axis/line
- Force is required for rotational movement
What is general motion?
- When 2 forms of movement are combined
What is a first class lever?
- The pivot point is located on the lever between the force and load (nodding your head)
What is a second class lever
- The load is in the middle of the lever between the pivot point and effort (calf raises)
What is a third class lever?
- The effort is in the middle of the lever between the pivot point and the load (bicep curls)
What is a vector?
- Nothing other than a force with direction and magnitude
What is velocity?
- The rate of change of position
- Need to combine speed with its direction of motion
What is momentum?
- The product of mass and velocity
What is linear force?
- When all forces occur along the same line of pull
What is parallel force?
- Forces that are aligned with each other but are either adjacent to each other or acting at different depths
What is concurrent force?
- When 2 or more forces connect at a common point but pull together in one direction
What is resultant force?
- The net result of 2 or more different forces
What is torque?
- Involves the rotation of an object around an axis
What is the center of gravity?
- The imaginary balancing point where the weight of an object is concentrated (changes during movement)
What is the base of support?
- The part/parts of the body in contact with a supportive surface such as the floor or ground
What is the line of gravity?
- An imaginary line that runs straight through your head, torso and center of gravity to the ground (plays a big part in posture and gait)
What is equilibrium?
- Dependent on the object’s center of gravity and its base of support
What is stable equilibrium?
- When an object’s center of gravity is in its lowest position (lying on your back)
What is unstable equilibrium?
- When an object’s stability is easily disturbed by a small force and its center of gravity is elevated (standing on one leg)
What is neutral equilibrium?
- When an object’s center of gravity is neither raised or lowered when disturbed (rolling ball on a flat surface)
What are the stability principles
- The lower the body’s center of gravity, the greater stability
- Widening the body’s base of support in the direction of the line of gravity will produce greater stability
- To maximize stability, the body’s line of gravity needs to pass through the base of support at the location which provides the greatest range of motion
- A person with more mass will be more stable
- The more friction between a surface and the body’s point of contact with that surface, the more stable it will be
What is the difference between open and closed kinetic exercises?
- Open: The body moves an object
- Closed: The object stays stationary and moves the body
