NCSF Biomechanics Flashcards
The rate, or a measure of the rate, of motion
Velocity
How quickly a position changes.
Speed
The capacity to do work.
Energy
Time rate of doing work or (Force x Distance)/Time
Power
The energy possessed by a body because of its motion.
Kinetic Energy
A change in the velocity of an object.
Acceleration
Transfer of energy by a force acting to displace a body
Work
The turning effect created by a force about an axis
Torque
A unit of power in the International System of Units equal to one joule per second.
Watt
Energy stored by an object by virtue of its position
Potential energy
Change in position that occurs when all points on an object move the same distance, in the same direction, and at the same time.
Linear motion
Mass of an object times the linear velocity of the object
Linear momentum
A single sided or unbalanced load
Asymmetrical load
A stable state characterized by the cancellation of all forces by equal, opposing forces.
Balance
The distance between the fulcrum and the point of resistance
Resistance Arm
A group of body segments connected by joints so that the segments operate together to provide a wide range of motion for a limb
Kinetic Chain
The role of a muscle whose torque opposes action
Antangonist
Role of a muscle whose torque aids the action, often referred to as the prime mover
Agonist
Name two internal forces that act on a body
- Tensile
2. Compressive
Name two external forces that act on a body
- Contact
2. Frictional
General motion is a combination of which two classifications of motion.
Angular
Linear
If the starting position is known, a particular motion can be quantified by:
Speed
Velocity
In weightlifting, positive work is known as:
Concentric Contraction
In weightlifting, negative work is known as;
Eccentric Contraction
Power output is dependent upon which two factors?
Quantity of Power
Time it is sustained
List three variables that can be manipulated to achieve bodily stability:
- Base of support
- Height of the center of gravity
- Line of gravitational pull
What are the four components that make up the inner unit of the lumbopelvic region?
- Transverse abdominis
- Pelvic floor
- Multifidus
- Diaphragm
What is the primary stabilizer for the lumbopelvic region?
Transverse abdominis
The amount of rotational inertia produced is dependent upon which three factors?
- Total mass
- Distribution of the mass
- Angular velocity
When swimming, water is an example of what kind of resistive force?
Contact Force
The concentric phase of a military press is an example of which of the following:
a. Negative work
b. Positive work
c. Potential Energy
d. Frictional force
B. Positive work
Which of the following has the greatest effect on a measured power output?
a. Muscle initial length
b. Neutralizing properties
c. Contractile velocity
d. Locations of the center of gravity
C. contractile velocity
Leg lifts are contraindicated due to:
a. the resistive torques place excessive stress on the rectus abdomens
b. the cervical spine may become strained
c. the hip flexors cause anterior pull on the spine leading to disc compression
d. the pelvis is pulled into a posterior tilt
C
What is a common biomechanics problem caused by performing the leg press exercise with tight hip extensors?
a. Pelvis migrates into a posterior pelvic tilt
b. The knees are forced past the toes
c. Cervical spine stress occurs due to neck flexion
d. All of the above
A
