phys of ex lab exam 2

Which of the following is true when comparing Knee Extensor v. Knee Flexor torque curves from our isokinetic experiments? a. 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. b. The torque curves for the knee extensors and the knee flexors simply produce a block like curve as the isokinetic machine forces them to contract maximally and generate full torque through out the range of motion. c. The torque curves for the knee extensors and the knee flexors are similar in their patterns. In each case the curves have low and high points related to changes in leverage and sticking points. In addition their peak

A

Which of the following would produce the greatest force? a. eccentric bicep curl 30deg/sec b. isometric bicep curl 0 deg/sec c. they would all be about the same d. concentric bicep curl 30 deg/sec

A

Which of the following would produce the greatest force? a. isometric action with high force arm:resistance arm ratio b. concentric action with low force arm:resistance arm ratio c. isometric action with low force arm:resistance arm ratio d. they would all be about the same

A

Which of the following would produce the greatest torque? a. eccentric knee extension 90 deg/sec b. eccentric knee extension 60 deg/sec c. eccentric knee extension 30deg/sec d. they would all be about the same

A

Which of the following would require the greatest recruitment of motor units with a 20 pound weight? a. concentric action with poor leverage b. isometric action with good leverage c. they would all be about the same d. isometric action with poor leverage

A

Which of the following would produce the least torque? a. eccentric knee extension 90 deg/sec b. eccentric knee extension 30deg/sec c. eccentric knee extension 60 deg/sec d. they would all be about the same

B

Which of the following would require the least number of motor units to be recruited when using a 15 lb weight? a. they would all be about the same b. isometric action with high force arm:resistance arm ratio c. isometric action with low force arm:resistance arm ratio d. concentric action with low force arm:resistance arm ratio

B

Which of the following fiber types would tend to have the lowest mitochondrial volume?

IIX

small female marathoner (best time 2 hrs 26 min 58 sec)

VO2max 69.1 ml/kg.min LT at 93.1 % of VO2max Absolute Maximum Anaerobic Power 351 W Relative Max Anaerobic Power 7.1 W/kg Accumulated O2 deficit 46.5 ml/kg

accumulated O2 deficit units

ml/kg

most healthy adults regardless of training status

30-60

untrained subjects

40-50

Which of the following fiber types would tend to be recruited first?

I

Which of the following fiber types would tend to have the greatest succinate dehydrogenase activity? (SDH catalyzes a step in the citric acid cycle)

I

Which of the following fiber types would tend to store the least glycogen?

I

Which of the following fiber types would tend to store the least intramuscular triglycerides (lipids)?

I

Myosin heavy chain IIA would be the predominant type of myosin in which fiber type?

IIA

Myosin heavy chain IIA and Myosin heavy chain IIX would both be found in which fiber type?

IIAX

Which of the following fiber types would tend to have the greatest amount of glycolytic enzymes?

IIC

Which of the following fiber types would be easiest to fatigue?

IIX

middle distance runners

70-80

sprinters

75-85

Which of the following would have the least EMG activity when using a 15 lb weight? a. isometric action with high force arm:resistance arm ratio b. they would all be about the same c. concentric action with low force arm:resistance arm ratio d. isometric action with low force arm:resistance arm ratio

A

Considering pennate muscles and parallel muscles, which of the following is/are NOT true? A. pennate arrangements allow for greater force production/strength compared to parallel arrangements B. longer fibers are associated with better potential for producing force C. pennate arrrangements would increase the physiological cross sectional area compared to parallel muscles D. Parallel arrangements are generally associated with longer muscle fibers than pennate arrangments E. three of the answers are NOT true

B

Which of the following would have the lowest EMG activity with a 20 pound weight at mid flexion (~90degrees)? a. they would all be about the same b. isometric action with good overlap of actin and myosin c. concentric action with good overlap of actin and myosin d. isometric action with poor overlap of actin and myosin

B

Which of the following would produce the greatest torque? a. eccentric knee extension 30deg/sec b. eccentric knee extension 90 deg/sec c. eccentric knee extension 60 deg/sec d. they would all be about the same

B

Which of the following would produce the least force? a. knee extensors 30 degrees/second b. knee flexors 90 degrees/second c. they would all be about the same d. knee flexors 30 degrees/second

B

Considering pennate muscles and parallel muscles, which of the following is/are NOT true? A. three of the answers are NOT true B. pennate arrangements allow for greater force production/strength compared to parallel arrangements C. longer fibers are associated with better potential for producing force D. Parallel arrangements are generally associated with longer muscle fibers than pennate arrangments E. pennate arrrangements would increase the physiological cross sectional area compared to parallel muscles

C

If we were using fine wire EMG and observed an increase in EMG frequency when our subject produced more force, this would be evidence of what type of summation? a. teporal summation b. multiple motor unit summation c. twitch summation d. asyncrhonous motor unit recruitment e. spatial summation

C

Which of the following isokinetic actions would have the lowest EMG integral? a. knee extensors 180 degrees/second b. knee extensors 300 degrees/second c. they would all be about the same d. knee extensors 30 degrees/second

C

Which of the following would have the lowest iEMG integral when using a 15 lb weight? a. they would all be about the same b. concentric bicep curl with forearm pronated moving at 90 degrees per second c. eccentric bicep curl with forearm pronated moving at 90 degrees per second d. eccentric bicep curl with forearm supinated moving at 30 degrees per second

C

Which of the following would have the lowest iEMG integral when using a 15 lb weight? a. concentric bicep curl with forearm pronated moving at 30 degrees per second b. they would all be about the same c. eccentric bicep curl with forearm pronated moving at 60 degrees per second d. eccentric bicep curl with forearm supinated moving at 10 degrees per second

C

Which of the following would produce the greatest torque? a. eccentric knee extension 60 deg/sec b. eccentric knee extension 30deg/sec c. eccentric knee extension 90 deg/sec d. they would all be about the same

C

Which of the following would produce the most torque? a. isokinetic knee extension early extension (90-100deg) b. isokinetic knee extension full extension (170-180deg) c. isokinetic knee extension mid-extension (125-135 deg) d. they would all be about the same

C

ou are the instructor of an exercise physiology lab course. All students enrolled in your course have just performed a Wingate test. One of the subjects you tested was a150 pound female sprinter on the track team. She specializes in the 100m and 4x100m relay. Her best 100m time is 11.79 seconds. For this subject, which of the following Wingate test variables would be highest compared to other females in the class? a. Accumulated O2 deficit b. Relative Anaerobic Capacity c. Relative Maximum Anaerobic Power d. Fatigue Index e. Absolute Anaerobic Capacity

C

The difference between the upper (red) EMG tracing and the lower (green) iEMG tacing is that the lower tracing has been ________________________. a. normalized b. high pass filtered c. low pass filtered d. rectified e. positivified

D

Which of the following would have the highest iEMG integral? a. isometric action with high force arm:resistance arm ratio b. isometric action with low force arm:resistance arm ratio c. they would all be about the same d. concentric action with low force arm:resistance arm ratio

D

You are the instructor of an exercise physiology lab course. All students enrolled in your course have just performed a Wingate test. One of the subjects you tested was a150 pound female sprinter on the track team. She specializes in the 100m and 4x100m relay. Her best 100m time is 11.79 seconds. For this subject, which of the following Wingate test variables would be highest compared to other females in the class? a. Accumulated O2 deficit b. Fatigue Index c. Absolute Anaerobic Capacity d. Relative Anaerobic Capacity e. Relative Maximum Anaerobic Power

E

___________________________________ is related to the orderly recruitment of motor units from lowest threshold to highest threshold a. multiple motor unit summation b. rate coding c. twitch summation d. asyncrhonous motor unit recruitment e. size principle

E

absolute VO2 units

L/min

large female 200m sprinter (best time 22.59s)

VO2max 31.6 ml/kg.min LT at 41 % of VO2max Absolute Maximum Anaerobic Power 788 W Relative Max Anaerobic Power 9.9 W/kg Accumulated O2 deficit 69.1 ml/kg

small female 100m sprinter (best time 11.32s)

VO2max 33.6 ml/kg.min LT at 44.5% of VO2max Absolute Maximum Anaerobic Power 632 W Relative Max Anaerobic Power 10.2 W/kg Accumulated O2 deficit 71.2 ml/kg

average sized female 1500m (middle distance) runner (best 1500m time 4min 14.6 sec)

VO2max 67.2 ml/kg.min LT at 79.6 % of VO2max Absolute Maximum Anaerobic Power 441 W Relative Max Anaerobic Power 7.2 W/kg Accumulated O2 deficit 68.5 ml/kg

If motor units are stimulated frequently enough we will observe no relaxation between twitches, this is called ____________________________

tetanus

absolute maximum anaerobic power units

watts

relative anaerobic capacity units

watts/kg

distance runners

45-55