phys of ex exam 2
Which of the following best describes the hold relax PNF procedure if the goal is to improve stretch of the hamstrings?
-We stretched the subject's hamstring passively until we reached the limits of its ROM. -Then we had the subject contract their hamstrings submaximally and then maximally while we held their leg in place -then had them relax while we pushed their leg further
How many degrees per second would you have a subject move if you wanted them to perform an isometric action?
0
A 200 lb individual has a body fat percentage of 15%. How many total calories of fat does this individual have stored?
105,000 Kcals
A subject weight 150lbs and stands 5'10" tall. What is their current BMI?
21.6
How much power is produced when performing a squat, your subject moved a/n 164 pound weight a distance of 0.27 meters in 0.90 seconds. No units required
219.2
The following image is a screen capture from your subject's best maximal voluntary contraction (MVC) attempt. How much force did this subject produce during their maximal voluntary contraction? (no units required)
30.43 (the pounds)
How much power is produced when performing a squat, your subject moved a/n 155 pound weight a distance of 0.37 meters in 0.80 seconds. No units required
319.3
Below you can find data from your subject's Thorstenson test. Calculate the fatigue index (FI, as a %) of this subject's extensors. work first third473312work second third417238work last 306207
64.7
iEMG integrals are often represented in scientific notation, which can be confusing for most. Which of the following iEMG integrals is the largest?
7.0 x 10-4
The following image is a screen capture from your subject's best maximal voluntary contraction (MVC) attempt. In a subsequent experiment you then had them hold a 15 pound weight isometrically at a 60 degree angle and at that angle their integral was 0.00014 with a delta T of 0.254 seconds. What was their normalized iEMG activity during this isometric action?
73.7
Below you can find data from your subject's Thorstenson test. Calculate the fatigue index (FI, as a %) of this subject's extensors. extensors 217.5 266 1241 434 398 327 flexors 113 160 734 320 242 184
75.35
Which of the following blood glucose values falls in the normal (not hyperglycemic, diabetic, or hypoglycemic) fasting range ? (note: mg% = mg/100ml = mg/dl)
80 mg%
Which of the following test would be an appropriate test to determine the power of the creatine phosphate system?
A 40 yard dash (4-8 seconds)
Peripheral fatigue can be seen by the following pattern of force and iEMG:
A decrease in muscle force, and an increase in iEMG.
Which of the following scenarios would create the largest error when assessing body composition by Bioelectrical Impedence?
A subject arrives substantially dehydrated from physical activity
During the Wingate test, the measurement that would best reflect the power of the ATP-PC system would be?
Absolute Anaerobic Power
Which of the following provide the largest energy reserves in the body?
Adipose
Which of the following individuals would have the greatest potential to generate muscular power?
An athlete with a high percentage of type II fibers, with the largest cross sectional area of muscle .
If a Male individual had a relative maximal anaerobic power of 17.6 watts/kg, we would consider them to be:
An elite athlete
Which of the following atheletes would have the best fatigue index during the Wingate test?
An elite marathon runner
As thermal stress increases, so does the release of epinephrine and norepinephrine. This endocrine change would result in the following:
An increase in glycogenolysis
During thermal stress, cardiac output must increase to drive blood to the skin. Due to this increase demand, the following would occur:
An increase in heart rate with a decrease in centralized blood volume
When a joint reaches a sticking point, what changes can be seen in iEMG activity?
An increase in iEMG
Which of the following is NOT a health related physical fitness attribute?
Balance
Which of the following is a true statement regarding blood glucose during exercise:
Blood glucose is tightly regulated during exercise and may only fluctuate during periods of rapid intense activity or very long activity.
Which of the following is untrue regrading Body Mass Index?
Body Mass Index is calculated using Height, Weight, and age.
When one needs to produce more force would you expect only multiple motor unit summation, only wave summation, or both types of summation to occur?
Both Multiple Motor Unit Summation and Wave Summation
iEMG amplitude would be highest for which of the following types of contractions under a constant load?
Concentric Contractions
Which of the following is NOT a mechanism in which Ca+ influences or is involved in fatigue?
Decreased [Ca+] reduces neurotransmitters within the CNS, decreasing motor output signals.
Power is a key determinant of athletic performance and can be calculated as: Power = Force (Newtons) x Velocity (Meters/sec). Which of the following muscle actions has the greatest potential to generate power when a maximal muscular effort is provided?
Eccentric Action
Which of the following is/are true about torque during different types of muscle action?
Eccentric Torque > Isometric Torque > Concentric Torque at any given velocity
A novice weight lifter is attempting a maximal 1 repetition bench press. During his final repetition, he presses the load upwards but cannot push through his sticking point. After several seconds of an isometric hold, he drops the weight as his muscles relax under the isometric tension. Which potential proprioceptor and neuromuscular reflex could have led him to dropping the weight?
Golgi Tendon Organs, Inverse Stretch Reflex
An anaerobically trained athlete with a greater anaerobic capacity will have an accumulated oxygen deficit:
Greater than an untrained idividual
Which of the following properties would NOT be a major determinant of muscular strength
High content of succinate dehydrogenase
Increases in the concentrations of ADP, H+, and Ca+ during exercise would alter metabolism in which of the following ways?
Increase glycogenolysis
Which of the following is NOT a potential cause of peripheral fatigue?
Increased [ADP] blocks access of action potentials to T-tubles
If the weather report (or your sling psychrometer) say that the wet bulb temperature was 74F and the dry bulb temperature was 75F. The temperature in the lab was 22C (75F), the subject's core temperature was 37.1C, and their skin temperature was 34.4. Which of the following are true about the humidity under these circumstances?
It is very humid
Some athletes are better at long events, some at short events, and some at intermediate distances. These different types of events require different physiological strengths (and permit certain weaknesses). Match the physiological test data with the best match for the different types of athletes below.
Large female 100m sprinter (best time 11.03s) - VO2max 31.5 ml/kg.min LT at 47% of VO2max Absolute Maximum Anaerobic Power 796 W Relative Max Anaerobic Power 9.7 W/kg Accumulated O2 deficit 68.2 ml/kg Small female 200m sprinter (best time 22.99s) - VO2max 34.7 ml/kg.min LT at 50.5 % of VO2max Absolute Maximum Anaerobic Power 628 W Relative Max Anaerobic Power 10.3 W/kg Accumulated O2 deficit 71.7 ml/kg small female 800m (middle distance) runner (best 800m time 2min 6.4 sec) - VO2max 68.2 ml/kg.min LT at 80.5 % of VO2max Absolute Maximum Anaerobic Power 369.4 W Relative Max Anaerobic Power 7.4 W/kg Accumulated O2 deficit 69.6 ml/kg average sized female distance runner (mostly 10k and half marathon, best 10k time is 34min 41 sec) - VO2max 69.1 ml/kg.min LT at 92.4 % of VO2max Absolute Maximum Anaerobic Power 435 W Relative Max Anaerobic Power 7.1 W/kg Accumulated O2 deficit 48.5 ml/kg
Which of the following represents the average percent body fat for a college aged male and female ?
Male 15.9% / Female 22.1%
An individual drops from a box height of 20 cm, and immediately jumps again following contact from the drop landing. Compared to their jump height from flat ground, the box jump created a higher vertical jump. What proprioceptor and reflex might have contributed to the increased jump height?
Muscle Spindle, stretch reflex
During fatigue as a result of isometric contractions, a decrease in motor neuron firing rate may occur and the contraction and relaxiation time of each twitch increases. This process may potentially help fatigue and is termed:
Muscle Wisdom
In lab we collected data related to force-velocity and power-velocity relationships. One such set of data is presented graphically below. Considering all Concentric data points on this curve, which likely has the greatest potentnial for producing power?
P eccentric side is a continous downward slop to concentric side and P is second lowest dot on concentric side
The process of glycogen breakdown, glycogenolysis, is catalyzed by which of the following enzymes?
Phosphorylase
The following data was sampled from an untrained and trained individual cycling at the same workload (200 watts). For each letter, select the appropriate explanation.
RER would be higher for the untrained individual, as the workload would be a greater percentage of their maximal ability compared to the trained person and would increase epinephrine and norepinephrine. Therefore, glycogenolysis would be increased, increasing carbohydrate usage and RER.
Which of the following statements is/are NOT true?
Radiation, Conduction, Convection, and evaporation are mechansims of heat transfer. At rest humans lose most of their heat by conduction
The process of taking negative iEMG, and incorporating it into positive iemg is termed?
Rectification
Which of the following tests best evaluates the ability to perform work by use of the lactic acid energy system?
The Wingate Test (30 Seconds)
The primary difference between the Wingate test and the Accumulated Oxygen Deficit Test test for assessing Anaerobic Capacity is?
The Wingate test assesses external work accomplished while the accumulated oxygen deficit test assesses internal metabolic work.
The Target Body Weight formula (AKA Desired (ideal) Body Weight Formula) is used to determine an appropriate weight to meet a desired body composition. Which of the following outlines the primary error associated with the formula?
The formula assumes all weight loss comes from body fat during weight loss, and lean body mass does not change
For the Isokinetic Action experiment (page 19, III) which of the following is true when comparing Knee Extensor v. Knee Flexor torque curves?
The knee extensors (quads) produce a greater peak torque, but a much narrow range in which peak torque is sustained compared to the knee flexors (hamstrings). This is due to the design of the knee extensors which are pennate fibers. Pennate fibers and their short fibers have a high torque output, but very limited range to sustain the torque due to the short fibers.
If a trained and untrained individuals of equal body size ran at 65% of their VO2max, we would expect the following:
The trained individual would demonstrate a lower RER, less carbohydrate reliance, and a lower lactate.
In order to dissipate heat, the body must create a thermal gradient from the core to the skin surface. We calculate thermal gradient using the following formula:
Thermal Gradient = Core Temperature - Skin Temperature
The following figure shows the iEMG tracing of the last 4 isometric actions that your subject performed as they approached fatigue. Which of the following is/are true about the following figure?
This figure suggests that the subject is experiencing central fatigue
Which of the following best describes the hold relax with agonist contraction PNF procedure if the goal is to improve stretch of the hamstrings?
We stretched the subject's hamstring passively until we reached the limits of its ROM. Then we had the subject contract their hamstrings submaximally and then maximally while we held their leg in place then had them relax while we pushed their leg further while the subject contracts their quadriceps muscles
Match the following measurements with the correct units of measurement
accumulated O2 deficit ml/kg fatigue index % absolute maximum anaerobic power Watts relative anaerobic capacity Watts/kg absolute VO2 L/min
The following image shows the EMG and iEMG activity of the biceps brachii during two muscle actions (X and Y). If one of these actions was in the supinated position and one was in the pronated position, which action is likely the pronated position?
action Y
A 20 year old male came to your lab for a fitness evaluation. He tries to get to the gym to do lift 2-3x/week and usually gets out for a fifteen to twenty minute jog once or twice a week. He used to throw the discus and javelin on his high school track team. At a recent 5k fundraiser he improved his time to 32.5 minutes. You determined that his VO2max was 38 ml/kg.min, his anaerobic threshold occurs at around 70% of VO2max, and his running economy is around 180 ml/kg.min. His weight was 190 pounds and is 6 feet tall. His waist circumference is 90 cm and his hip circumference is 99 cm. Using skinfolds he was 16% body fat and using bioelectrical impedance he was 19.5% body fat. Considering ALL of the relevant data you have available, do you think he is 1) aerobically fit or unfit (select A or B)? 2) of normal weight or overweight? (select C or D), 3) is there any reason to believe that he has elevated health risk? (if yes select E), then check all variables that helped you determine these answers (select from among F to J)
aerobically unfit around normal weight His VO2max His percent body fat his waist to hip ratio his 5 k running pace
Type I fibers would have the highest numeric value for which of the following variables compared to type IIX fibers?
all provided choices are correct
In lab we collected data related to force-velocity and power-velocity relationships. One such set of data is presented graphically below. Why does point P have a low value on this figure? decrease(eccentric) and big hump (concentric)
at that point velocity is low so power is low; power = force x velocity
In one of our lab activities we used proprioreceptive neuromuscular facilitation, PNF, to try to inhibit muscle contraction and thus improve the ability to stretch a muscle (in our experiment we were stretching the muscle). The following depicts the reflex arc for reciprocal inhibition of the hamstrings. Match the letters with the most appropriate description. Note: hamstrings are innervated by the sciatic nerve and quadriceps femoris by the femoral nerve. hamstrings afferent nerve sciatic nerve excitatory synapse inhibitory synapse muscle spindle
b i c g f j
The EMG data below was collected during a variety of activities from the abdominal muscles (abs) and from the rectus femoris (hip flexors). Which of the following exercises best activates the abdominal muscles? abs/concentric 1.81E-04 hip flexors/concentric 9.40E -05
bent knee sit up
During our "jumping" experiment we had our subject jump with or without a counter-movement, and we also had our subject perform some "drop jumps". We recorded EMG activity from the vastus lateralis and jump height during each. Here are some sample results from these experiments. What is a likely explanation for the increase in jump height between the 0.5m drop jump and the 0.25m drop jump? left 14 12 16 18 right 0.00085 0.00077 0.00092 0.00092
better use of energy return from structures like elastin and titin
During our "jumping" experiment we had our subject jump with or without a counter-movement, and we also had our subject perform some "drop jumps". We recorded EMG activity from the vastus lateralis and jump height during each. Here are some sample results from these experiments. What is a likely explanation for the increase in jump height between the 0.5m drop jump and the 0.25m drop jump? counter movement jump 14 no counter movement 12 0.25m drop jump 16 0.5m drop jump 18 0.00085 0.00077 0.00092 0.00092
better use of the elastic components of the muscle
Which of the following images correctly shows the iEMG for the concentric and eccentric activity of the biceps during a dynamic free weight activity at 70% of 1 repetition maximum?
concentric and eccentric both V shapes but concentric is higher
The EMG data below was collected during a variety of activities from the abdominal muscles (abs) and from the rectus femoris (hip flexors). Which of the following exercises best activates the abdominal muscles? abs concentric 0.00018 plank concentric 0.00011
crunch
Proprioceptive information that is perceived by the subject is brought up the spinal cord via ascending spinal cord tracts called the ____________________________
dorsal columns/lemniscal
Which image shows the appropriate iEMG activity for Dynamic and Isokinetic activities? The dynamic activity was conducted while knee extending a load at 50% of maximal.
dynamic is a V shape isokinetic is a square
The following figure depicts EMG and iEMG activity during dynamic bicep curls until the subject could not lift the weight anymore. They lifted the weight 17 times before they fatigued. Which of the following mechanism(s) are LEAST likely to be causing this fatigue, given this set of data?
failure to release enough acetylcholine at the neuromuscular junction
A cell or organism can use anaerobic metabolism only when their is a total lack of oxygen availability.
false
Which of the following should be a priority if one wants to compare iEMG activity between subjects. For instance, what needs to be considered when we compare the iEMG activity of abdominal muscles from well trained and untrained subjects.
iEMG should be normalized for both subjects to account for differences in signal resistance
When using the hold-relax procedure to try to increase the stretch of a muscle we make use of which of the following reflex phenomena?
inverse stretch reflex
Which of the following is NOT a potential mechanism that contributes to peripheral fatigue of skeletal muscle?
lactate can directly interfere with actin - myosin interactions and thus reduce force production
Considering pennate muscles and parallel muscles, which of the following is/are NOT true?
longer fibers are associated with better potential for producing force
A version of this figure can be found in your textbook and is taken from a classic study by Romjin et al (Am J Physiology, 1993). It depicts different sources of fuel used to support muscular activity at different intensities. Please match the major sources of fuel with the correct shaded ares on the figure.(Note: you do not need to memorize this figure - think about what fuels are used preferentially in these different intensity ranges. )
muscle protein- Not a major fuel for exercising muscle & not shown on figure i- muscle glycogen ii- muscle triglycerides iii- plasma free fatty acids iv- plasma glucose
Which of the following images represents the torque curves for a Pennate and Parallel muscle architecture? Assume the individual has good leverage at 120 degrees and poor leverage at 180 and 80 degrees.
pennate skinny tall slope parallel short stubby
Match the following enzymes with the appropriate metabolic pathway/process:
phosphofructokinase glycolysis phosphorylase glycogenolysis glycogen synthase glycogenesis hormone sensative lipase lipolysis no hormone listed matches this process lipogenesis
During the second phase of the hold-relax with agonist contraction procedure to try to increase the stretch of a muscle we make use of which of the following reflex phenomena?
reciprocal inhibition
The difference between the upper (red) EMG tracing and the lower (green) iEMG tacing is that the lower tracing has been ________________________.
rectified
The following figure depicts EMG and iEMG activity during dynamic bicep curls until the subject could not lift the weight anymore. They lifted the weight 17 times before they fatigued. Which of the following mechanism(s) are LEAST likely to be causing this fatigue, given this set of data?
reduced excitability in motor areas of the cerebral cortex
Which of the following is/are true about the body's glycogen stores?
skeletal muscle glycogen stores are larger than glycogen stores elsewhere in the body Beyond moderate intensities, most carbohydrate catabolism comes from glycogenolysis, not circulating glucose
Chronic exercise training would reduce the amplitude and severity of endocrine responses during exercise stress.
true
During wave summation, a muscle receives an increase in the frequency at which it is stimulated to increase force production.
true
The ATP-PC system recovers more rapidly then the lactic acid system.
true
The accumulated oxygen deficit test requires a subject to hold a supra maximal bout of exercise to exhaust their anaerobic capacity. To determine the total capacity, the actual VO2 for each minute of exercise is subtracted from the expected VO2 from the supra maximal bout of exercise.
true
Which of the following is/are NOT true about the effects of training on fuel substrate choice?
untrained subjects would tend to have more fat stores, and this is the main reason that untrained subjects rely more on fats than trained subjects
