Anatomy, Physiology, & Biomechanics Flashcards
What are the biomechanical factors in human strength? Describe each
Neural control Muscle cross-sectional area Arrangement of muscle fibers Muscle length Joint angle Muscle contraction velocity Joint angular velocity Strength-to-Mass ratio Body Size
Describe the sources of resistance to muscular contraction:
- Gravity: The downward force on objects from gravity, known as the weight of the object.
- Inertia: This is in addition to gravity. When weight is accelerated, it puts inertial force on the person doing the action.
- Friction: This is the force that happens when you are moving an object that is against another object.
- Fluid resistance: When moving through a liquid or gas, the fluid that moves around the object, or through an opening, puts added resistance force.
- Elasticity: The further you stretch something that is elastic, the more resistance it has.
Explain how intra-abdominal pressue works when lifting weights
When the deep torso muscles and the diaphragm contract, this creates pressure within the abdominal cavity. Because of there being little gas present, it is seen as incompressible and described as a “fluid ball”. This pressure supports the vertebral column during resistance training. All in all, this helps to reduce the forces that are needed by the erector spinae in order to perform exercises and also reduces the compressing forces that act on our disks. Weight belts are known to increase this intraabdominal pressure and help with weightlifting.
What is a First Class Lever
This is a lever where both the muscle force and the force of resistance act on opposite sides of the fulcrum. The best and one of the only examples is the triceps during a tricep extension. The tricep and the force are on opposing sides of the fulcrum.
What is a Second Class Lever
This is a lever where the weight is located between the axis and the force applied. There is a major mechanical advantage in these levers. In other words, the required force of the muscle is much smaller than the force of resistance. One example is the calf muscle during a calf raise. The muscle force is high, the moment arm is in the middle, and the fulcrum is the bottom (or the ball of your foot).
What is a Third Class Lever
This is the most common lever type in the body. Third class levers are where the force is applied between both the resistance and the fulcrum. Like when shoveling dirt, the back of the handle is the fulcrum, the force is where your hand is in the middle of the shovel, and the shovel head has the resistance. An example in the body would be a bicep curl with the biceps.
What is the formula for determining the strength to mass ratio?
Bodyweight^(2/3)
What is the definition of Power?
Force x Velocity
Define biomechanics
Study of the mechanisms through which musculoskeletal components interact to create movement
Define Mechanical Advantage
The ratio of the moment arm through which an applied force acts to that through which a resistive force acts (figure 2.1) For there to be a state of equilibrium between the applied and resistive torques, the product of the muscle force and the moment arm through which it acts must equal the product of the resistive force and the moment arm through which it acts. Therefore, a MA, represented as a ratio greater than 1.0, allows the applied (muscle) force to be less than the resistive force to produce an equal amount of torque.
Isaac Newtons 2nd Law
Force = Mass x Acceleration
Time rate of doing work
Power
The product of the force exerted on an object and the distance the object moves in the direction the force is exerted…
work
Define #work
Work = Force x Displacement
Equation for Power
Power = Work / Time
What is Angular Displacement?
The angle through which an object rotates
The angle through which an object rotates is called?
Angular Displacement
Define Angular Velocity
The objects rotational speed measured in radians per second
How do you calculate rotational work?
Rotational work = Torque x Angular Displacement
What is meant by ‘Recruitment’ and how does it affect muscle contraction?
This a Neural control and it affects the maximal force output of a muscle by determining which and how many motor units are involved in muscle contraction.
What is rate coding`?
The rate at which motor units are fired.
Define Pennate
Pennate muscles have fibers that align obliquely with the tendon, creating a featherlike arrangement.
What is a Pennate Angle?
The angle between the muscle fibers and an imaginary line between the muscles origin and insertion.
Calculate the work of an athlete squatting 100kg 2 meters per rep, taking 2s per meter, for 10 reps.
- Determine the weight of the bar in SI units. Multiply the mass of the bar x 9.8m/s^2 9.8m/s^2 x 100kg = 980 N (Newtons) 2. Calculate additional force required to accelerate the bar at a given rate. Force applied to the bar = 2m/s^2 x 100kg = 200 N 3. Apply the following equation: Work = (Mass + Acceleration) x 2 m x 10 reps = Joules Work = (980 N + 200 N) x 2 m x 10 Reps = 23,600 J
Name the major bones of the body:
Image attached
Explain levers (like I’m 5):
There are 4 parts to the lever system in the body:
1) A rigid structure (a bone or group of bones)
2) a force acting upon it (muscle) to create a rotational force at the
3) fulcrum which is a fixed point (our joints).
4) Finally, an external force placed on the rigid structure (a weight).
What is Hydrolysis?
The breakdown of an ATP molecule to produce energy. This requires the enzyme ATPase.
There is an image attached of a muscle cell.
Explain every aspect of this image:
Figure 1.3 (page 4)
Name the major bones of the axial skeleton:
Skull, Ribs, Vertebrae
Name the parts of a motor unit and the neuromuscular junction:
Image (figure 1.4)
Name the different types of joints.
Fibrous, Cartilaginous, Synovial
List the sections of the vertebral column and the number of vertebrae in each:
32-34 total
Cervical – 7
Thoracic – 12
Lumbar – 5
Sacral – 5 (fused together)
Coccygeal – 3-5
Relative involvement of muscle fiber types in sports:
Table 1.2
Pick 5 sports and give their type.
100-800m sprint, marathon, weightlifting, soccer/lax/hockey, football, basketball, volleyball, baseball, boxing, wrestling, 50m swim, cross-country skiiing, tennis, downhill skiiing, speed skating, track cycling, rowing.
Name the major characteristics of the different muscle fibers:
Table 1.1
Pick 5 and explain:
Explain what the sliding filament theory in a single sentence:
The sliding filament theory states that the actin filaments at each end of the sarcomere slide inward on myosin filaments, pulling the Z lines closer together and thus shortening the muscle fiber.
What are the steps in the sliding filament theory?
- Resting Phase – very little calcium, very little interaction.
- Excitation-Contraction Coupling phase – Myosin cross-bridge attaches to the actin filament.
- Contraction Phase – Energy for the power stroke comes from hydrolysis of ATP.
- Recharge Phase – dissociation of actin and myosin, resetting of the myosin head position.
- Relaxation Phase – occurs when motor nerve stimulation stops. Calcium goes back to the sarcoplasmic reticulum and actin & myosin go back to their normal state.
Identify the different parts of a sarcomere:
How can athletes improve force production?
Recruit more fiber and motor units by lifting heavier loads while using multiple joint exercises
Whats the difference between muscle spindles and GTOs?
Muscle spindle are sensitive to the stretch and rate of stretch in a muscle while GTO’s respond to tension and rate of tension. Muscle spindles are located in the muscle. GTO’s are located in the tendon.
Explain the flow of blood through the heart:
What does the CV system actually do?
Distributes nutrients, removes waste, carries O2
What does the Respiratory system actually do?
Delivers O2 and removes CO2
What is the pathway of blood through the heart?
Explain what origin and insertion are. What other terms are commonly used with these two?
Origin is usually proximal (closer toward the center of the body)
Insertion is usually distal (further from the center of the body)
What are the main muscle roles? Give an example of each during a biceps curl:
Agonist (Biceps), Antagonist (Triceps), Synergist (Rotator Cuff)
List the planes of movements and the joint motions that occur in each:
Sagittal – Flexion/Extension, Dorsiflexion/Plantarflexion
Frontal – Adduction/Abduction, Lateral Flexion, Inversion/Eversion
Transverse – Rotation, Horizontal Adduction/Abduction, Internal/External Rotation
Explain the terms Anabolic and Catabolic. Relate them to other commonly associated terms:
Anabolism - Engergonic reactions
Catabolism - Exergonic reactions
Name the 3 energy systems and time frames for each, including the crossovers:
Phosphagen - 0-6s
Both - 6-30s
Glycolysis - 30s-2min
Both - 2-3min
Oxidative - >3min
What is the Cori Cycle and what does it do?
Explain Lactate threshold:
the exercise intensity or relative intensity at which blood lactate begins an abrupt increase above the baseline concentration.
Generally occurs at 50-60% of maximal O2 intake for untrained and 70-80% of trained individuals.
Explain OBLA:
This is the second point of inflection and occurs when the concentration of blood lactate reaches 4mmol/L.
LT and then OBLA
