Biomechanics

Question 1

What are agonists, antagonists, and synergists?

Answer 1

• Agonist- Prime Mover
• Antagonist- Slows down agonist movement
• Synergist- Indirectly assists agonist

Question 2

What is a first class lever?

Answer 2

• mm force and resistive force act on opposite sides of the fulcrum
• Elbow Extension (Triceps)

Question 3

What is a second class lever?

Answer 3

• mm force and resistive force act on same sides of fulcrum and are close together
• Plantarflexion against resistance

Question 4

What is a third class lever?

Answer 4

• mm force and resistive force act on same side of fulcrum but are far apart
• Elbow Flexion (biceps)

Question 5

GIve Basic Calculations for Acceleration, Force, and Strength

Answer 5

• Acceleration- Change in velocity per unit of time
• Force- Mass x Acceleration
• Strength- Max force a mm can generate at a specified velocity

Question 6

How do you calculate Work?

Answer 6

• Product of the Force exerted on an object and the distance the object moves
• Force x Distance

Question 7

Give an example of calculating Work

Answer 7

• Work involved in lifting 100kg barbell 2m per repetition for 10 reps
• Force = 100 x 9.8m/s2 = 980 Newtons
• Force x Distance = 980 x 2M x 10 reps = 19,600 Joules

Question 8

How do you calculate strength to mass ratio?

Answer 8

• Load lifted is divided by body weight to the two thirds power

Question 9

What is the Bracketing Technique of Weight Training?

Answer 9

• Athlete performs the sport movement with less than normal weight or more than normal resistance
• EG: Shot Putter with less weight, Sprinter with parachute

Question 10

What are some Central Nervous System adaptations to anaerobic training?

Answer 10

• Primary Motor Cortex activity increases when level of force developed increases and when new exercises or movements are being learned

Question 11

What are some adaptations to motor units with anaerobic training?

Answer 11

• Increase in Recruitment and synchronization of firing
• Muscle Fibers get larger
• Selective recruitment allows athletes to recruit motor units with higher threshold sooner and inhibit low threshold units

Question 12

What are some EMG findings due to anaerobic training?

Answer 12

• Cross Education- Training of one limb increases strength in other
• Using both limbs at same time produces less force that the sum of both single limb force production, can improve with training
• Antagonist co-contraction decreases

Question 13

What are some muscular adaptations to anaerobic training?

Answer 13

• Muscle Hypertrophy
• Fiber Type Change IIx to IIa
• Increase in density of Myofibrils, Sarcoplasmic Reticulum, and T Tubules
• Sharper angle of pennation in pennate mm
• Delayed fatigue d/t higher lactate threshold

Question 14

How do you encourage bone adaptations to anaerobic training?

Answer 14

• Use exercises with direct force vectors through spine, hip and involve multiple mm groups
• Progressive Overload
• Varied Program

Question 15

How does connetive tissue respond to exercise?

Answer 15

• High intensity loading increases net growth
• Weight Bearing and full ROM exercise is needed to maintain cartilage health
• Moderate Aerobic exercise is adequate for increasing cartilage thickness

Question 16

What is Overreaching?

Answer 16

• Excess training on a short term basis

Question 17

What are key symptoms for anaerobic overtraining?

Answer 17

• Decreased joy and desire to train
• ## Acute Epinephrine and NorE increase beyond exercise induced change

Question 18

What are the main components involved in stimulation of bone growth?

Answer 18

• Magnitude of load
• Rate of load
• Direction of Forces
• Volume of Loading (reps)

Question 19

What are some Acute Cardiac responses to Aerobic Exercise Training?

Answer 19

• Increased Cardiac Output
• Increased Stroke Volume
• Increased Heart Rate
• Increase Oxygen Uptake
• Increase in Systolic BP, Diastolic stays same or very slightly decreases

Question 20

What is Cardiac Output?

Answer 20

• Amount of blood pumped by hear in liters/min
• Stroke Volume x heart rate
• Initially increases with exercise and eventually plateaus

Question 21

What is Stroke Volume?

Answer 21

• Amount of blood pumped in one contraction of the heart

Question 22

What are two mechanisms responsible for regulation of Stroke Volume?

Answer 22

• End Diastolic Volume- Volume of blood available to be pumped by Left Ventricle at end of filling
• Action of Catecholamines- Epi and NorE produce more forceful Ventricular contraction and greater emptying of ventricle occurs

Question 23

What is the arteriovenous oxygen difference (a-VO2 difference)?

Answer 23

• Difference in oxygen content between arterial and venous blood

Question 24

What is the Fick Equation?

Answer 24

• Way to calculate VO2 (oxygen uptake)
• VO2 = Heart rate x Stroke Volume x a-VO2 difference
• VO2 = Cardiac Output (Q) x a-VO2 difference

Question 25

What is a MET or Metabolic Equivalent of Tasks?

Answer 25

• Estimated as the bodies resting oxygen uptake
• 3.5 ml of Oxygen per Kilo of body weight per minute
• 3.5ml O2/ Kg BW (min)

Question 26

What are Minute Ventilation and Tidal Volume?

Answer 26

• Minute Ventilation- Amount of air breathed per minute

- Tidal Volume- Amount of air inhaled and exhaled with each breath

Question 27

What are some Cardiovascular Adaptations to Chronic Aerobic Exercise?

Answer 27

• Most importantly, Increased Max Cardiac Output
• Increased Stroke Volume
• Reduced heart rate at rest
• Increased Capillarization

Question 28

What are some Respiratory Adaptations to Chronic Aerobic Exercise?

Answer 28

• With Max Exercise Tidal Volume is increased and breathing frequency increased
• With Sub Max Tidal Volume is increased but frequency is decreased

Question 29

What are some Muscular Adaptations to Chronic Aerobic Exercise?

Answer 29

• Increased Aerobic Capacity of trained muscle
• Glycogen sparing and increased fat utilization
• Increased Mitochondria and Myoglobin Content

Question 30

What is the main pathway in energy production?

Answer 30

• Krebs Cycle and Electron Transport Chain

- Aerobic Metabolism produces more ATP than anaerobic and uses fats, carbs, and proteins

Question 31

What are some adaptations made with training at altitude?

Answer 31

• Increase Hemoglobin and Red Blood Cells
• Increased diffusing capacity of oxygen through pulmonary membranes
• Increased Capillarization
• Regardless of acclimatization, performance while at altitude is typically less than at sea level