Biomechanics Flashcards
What are agonists, antagonists, and synergists?
- Agonist- Prime Mover
- Antagonist- Slows down agonist movement
- Synergist- Indirectly assists agonist
What is a first class lever?
- mm force and resistive force act on opposite sides of the fulcrum
- Elbow Extension (Triceps)
What is a second class lever?
- mm force and resistive force act on same sides of fulcrum and are close together
- Plantarflexion against resistance
What is a third class lever?
- mm force and resistive force act on same side of fulcrum but are far apart
- Elbow Flexion (biceps)
GIve Basic Calculations for Acceleration, Force, and Strength
- Acceleration- Change in velocity per unit of time
- Force- Mass x Acceleration
- Strength- Max force a mm can generate at a specified velocity
How do you calculate Work?
- Product of the Force exerted on an object and the distance the object moves
- Force x Distance
Give an example of calculating Work
- 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
How do you calculate strength to mass ratio?
- Load lifted is divided by body weight to the two thirds power
What is the Bracketing Technique of Weight Training?
- Athlete performs the sport movement with less than normal weight or more than normal resistance
- EG: Shot Putter with less weight, Sprinter with parachute
What are some Central Nervous System adaptations to anaerobic training?
- Primary Motor Cortex activity increases when level of force developed increases and when new exercises or movements are being learned
What are some adaptations to motor units with anaerobic training?
- 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
What are some EMG findings due to anaerobic training?
- 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
What are some muscular adaptations to anaerobic training?
- 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
How do you encourage bone adaptations to anaerobic training?
- Use exercises with direct force vectors through spine, hip and involve multiple mm groups
- Progressive Overload
- Varied Program
How does connetive tissue respond to exercise?
- 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
What is Overreaching?
- Excess training on a short term basis
What are key symptoms for anaerobic overtraining?
- Decreased joy and desire to train
- ## Acute Epinephrine and NorE increase beyond exercise induced change
What are the main components involved in stimulation of bone growth?
- Magnitude of load
- Rate of load
- Direction of Forces
- Volume of Loading (reps)
What are some Acute Cardiac responses to Aerobic Exercise Training?
- Increased Cardiac Output
- Increased Stroke Volume
- Increased Heart Rate
- Increase Oxygen Uptake
- Increase in Systolic BP, Diastolic stays same or very slightly decreases
What is Cardiac Output?
- Amount of blood pumped by hear in liters/min
- Stroke Volume x heart rate
- Initially increases with exercise and eventually plateaus
What is Stroke Volume?
- Amount of blood pumped in one contraction of the heart
What are two mechanisms responsible for regulation of Stroke Volume?
- 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
What is the arteriovenous oxygen difference (a-VO2 difference)?
- Difference in oxygen content between arterial and venous blood
What is the Fick Equation?
- Way to calculate VO2 (oxygen uptake)
- VO2 = Heart rate x Stroke Volume x a-VO2 difference
- VO2 = Cardiac Output (Q) x a-VO2 difference
What is a MET or Metabolic Equivalent of Tasks?
- 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)
What are Minute Ventilation and Tidal Volume?
- Minute Ventilation- Amount of air breathed per minute
- Tidal Volume- Amount of air inhaled and exhaled with each breath
What are some Cardiovascular Adaptations to Chronic Aerobic Exercise?
- Most importantly, Increased Max Cardiac Output
- Increased Stroke Volume
- Reduced heart rate at rest
- Increased Capillarization
What are some Respiratory Adaptations to Chronic Aerobic Exercise?
- With Max Exercise Tidal Volume is increased and breathing frequency increased
- With Sub Max Tidal Volume is increased but frequency is decreased
What are some Muscular Adaptations to Chronic Aerobic Exercise?
- Increased Aerobic Capacity of trained muscle
- Glycogen sparing and increased fat utilization
- Increased Mitochondria and Myoglobin Content
What is the main pathway in energy production?
- Krebs Cycle and Electron Transport Chain
- Aerobic Metabolism produces more ATP than anaerobic and uses fats, carbs, and proteins
What are some adaptations made with training at altitude?
- 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
