Biopac Student Lab                   Lesson 2: EMG II  

Lesson 2

 

ELECTROMYOGRAPHY II

 

Motor unit recruitment and Fatigue

 

DATA REPORT

Student’s Name: ______________________________________

 

Lab Section: ___________________________________________

 

Date. _____________________________________________

 

 

I.        Data and Calculations

Motor Unit Recruitment

DATA REPORT

Student’s Name: ______________________________________

 

Lab Section: ___________________________________________

 

Date. _____________________________________________

 

 

I.        Data and Calculations

Motor Unit Recruitment

 

Subject Profile

 

Name _____________________________

 

Height ________________________

Age ______________________________

 

Weight ________________________

 

         Gender:         Male or Female                               Dominant forearm: Right / Left

 

A.   Complete Table 2.1 using Segment 1 data. In the “Force (kg) Increments” column, note the force increment assigned for your recording under Peak #1; the increment was pasted to the Journal and should be noted below from Data Analysis—Step 2. For subsequent peaks, add the increment (i.e.. 5, 10, 15 or 10, 20, 30). You may not need nine peaks to reach max.

 

 

 

 

 

 

 

 

 

 

 

 

Table 2.1 Segment 1 data

 

 

Forearm 1 (Dominant)

Forearm 2

Peak #

Force (kg) Increments

Assigned

 

Force at peak (Ch 1) Mean

(Kg)

 

Int. EMG (Ch 40)

Mean

(mV)

Force at peak (Ch 1) Mean

(Kg)

 

Int. EMG (Ch 40)

Mean

(mV)

1

5 kg

 

 

 

 

 

 

2

10 kg

 

 

 

 

 

 

3

15 kg

 

 

 

 

 

 

4

20 kg

 

 

 

 

 

 

5

25 kg

 

 

 

 

 

 

6

30 kg

 

 

 

 

 

 

7

35 kg

 

 

 

 

 

 

8

40 kg

 

 

 

 

 

 

9

45 kg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fatigue

B.        Complete Table 2.2 using Segment 2 data from each arm.

Table 2.2 Segment 2 data

 

Forearm 1 (Dominant)

Forearm 2

Maximum Clench Force

50% of max Clench Force

Time to Fatigue

Maximum Clench Force

50% of max Clench Force

Time to Fatigue

Ch 1 value

Calculate

Ch 40 delta T

Ch 1 value

Calculate

Ch 40 delta T

 

 

 

 

 

 

 

 

 

 

 

*Note:  You do not need to indicate the delta T (time to fatigue) polarity. The polarity of delta T measurement reflects the direction the ‘I-beam” cursor was dragged to select the data. Data selected left to right will have a positive (‘+‘) polarity, while data selected right to left will have a negative (“-“) polarity.

 

II.     Questions

 

A.    Is the strength of your right arm different than your left arm? _______Yes _______No

 

B.    Is there a difference in the absolute values of force generated by males and females in your class? Yes_______No What might explain any difference?

 

 

 

C.    When holding an object, does the number of motor units remain the same? Are the same motor units used for the duration of holding the object?

 

 

 

D.    As you fatigue, the force exerted by your muscles decreases. What physiological processes explain the decline in strength?

 

 

E.     Define Motor unit

 

 

F.    Define Motor unit recruitment

 

 

G.    Define Fatigue

 

 

H.     Define EMG

 

 

I.      Define Dynamometry     

 

 

 

 

 

End of Lesson 2 Data Report