It was the original plan in this investigation that strength and endurance tests should be given to the members of the squads from time to time in the gymnasium at Springfield. Circumstances over which we had no control interfered and this part of the plan failed to materialize. Strength of grip was therefore made a part of the psychological program to help offset this deficiency. There are no records for the normal session of Squad A, i. e., for September 29, with which the later ones may be compared. The results from tests made in the evening are given in tables 161 and 162 and entered separately for right and left hands. Five trials were made alternately with each hand, the figure given being the average of the five in kilograms. For each average there is a standard deviation and coefficient of variability.

In the evening records of Squad A (table 161), October 27 to February 2, inclusive, are during the low-diet period. As would be expected, the total individual averages are higher for the right hand than for the left.1 The average for the right is 48.1 and for the left, 44.7, with a difference of about 3.5 kg. The individuals are very closely grouped. For the right hand the range is from 56.6 (Gul) to 41.6 kg. (Pea). The last-mentioned subject was left-handed. Kon shows almost equally good scores for both his hands. His record for the left hand of 54.8 kg. is the highest for the squad; the lowest average record with the left hand is 36.0 kg. for Mon. Five trials is not a large number from which to compute variability, but with the strength of grip test it is not desirable to take a large number of trials, since the element of fatigue soon enters as a prominent factor.

As explained in the section on method (page 150), the trials were separated by suitable intervals to minimize fatigue and to secure as nearly as possible an even performance. The general success of this can be judged definitely by the average coefficients of variability shown in the extreme right-hand column of the table with the other averages; these range from 3 to 6 per cent. Inspection of the table will show that the individual subjects were remarkably consistent in showing this small variability. The largest variability was with Pea on January 12 for the right hand - 18.3 per cent. For this there is an explanation in that the subject had a sprained wrist which pained him when he used his full strength.

Squad B (table 162) showed averages higher than those of Squad A. The general averages for the four normal experiments are 55.1 kg. for the right hand and 51.6 kg. for the left as compared with 48.1 and 44.7 kg. for right and left, respectively, of Squad A. The individual subjects are here also very closely grouped about the general average.2 Squad B in its low-diet averages for January 13, 19, and 27 has a total average for the right hand slightly above the normal (56.1 compared to 55.1 kg.) and for the left hand slightly below normal (50.9 compared to 51.6 kg.). The individuals indicate some change between the two groups of sessions. The most marked is in the case of How, whose low-diet average with the left hand of 40.0 differs widely from his normal average of 55.8 kg. He also shows a change in the same direction, but not so large, with the right hand, of 59.8 as compared with 62.6 kg. In their fluctuations the subjects are about equally divided, for example: with the right hand, 5 of them, Fis, Har, Ham, Liv, and Tho, show somewhat better results under the reduced diet condition, while the remaining subjects, and How in particular, show decreases.

1 In Squad A Pea and Spe were left-handed.

2 Kim, Lit, Sch, and Wil, of Squad B, were left-handed; the first two are not included in the general averages.

Table 161. - Squad A - Strength Of Grip At Evening Sessions

[Values In Kilograms]

Date.

Hand.1

Bro.

Can.

Kon.

Gar.

Gul.

Mon.

Moy.

Pea.

Pec.

Spe.

Tom.

Vea.

Av.

1917.

Oct. 27...

R.

M.

51.1

63.1

59.5

46.4

60.2

39.2

42.9

46.9

49.8

48.0

45.5

43.7

48.9

S. D.

2.28

2.17

4.09

2.11

1.32

2.25

1.77

1.69

.91

2.87

2.49

2.36

1.94

C.

4.5

3.4

6.9

4.5

2.2

5.7

4.1

3.6

1.8

6.0

5.5

5.4

4.1

L.

M.

43.8

54.2

56.1

45.0

53.3

34.5

42.7

50.2

52.8

50.4

44.5

41.1

46.2

S. D.

1.49

3.24

1.76

2.07

3.78

2.95

2.39

3.12

3.02

2.85

1.72

3.47

2.73

C.

3.4

6.0

3.1

4.6

7.1

8.6

5.6

6.2

5.7

5.6

3.9

8.4

6.0

Nov. 10...

R.

M.

53.2

58.5

58.3

52.1

58.9

43.4

45.0

42.7

46.0

45.6

51.4

45.4

49.7

S. D.

.98

.84

.68

1.74

.37

1.77

2.55

1.17

.89

1.83

1.50

1.53

1.33

C.

1.8

1.4

1.2

3.3

6.3

4.1

5.7

2.7

1.9

4.0

2.9

3.4

3.4

L.

M.

46.0

55.7

56.0

43.5

52.1

35.0

42.4

50.5

46.8

46.1

48.3

43.7

46.4

S. D.

.71

1.99

1.14

1.42

1.32

2.03

2.85

2.80

1.17

3.15

1.47

1.91

1.77

C.

1.5

3.6

2.0

3.3

2.5

5.8

6.7

5.5

2.5

6.8

3.0

4.4

3.9

Nov. 24...

R.

M.

49.0

53.3

56.3

50.7

58.6

42.4

48.0

39.0

44.1

47.3

51.9

45.9

48.3

S. D.

2.55

1.40

.79

1.33

1.66

2.03

1.23

6.30

.56

2.32

2.39

1.24

1.97

C.

5.2

2.6

1.4

2.6

2.8

4.8

2.6

16.2

1.3

4.9

2.7

2.7

4.4

L.

M.

45.1

47.2

54.5

43.7

51.7

36.9

44.0

50.1

44.6

46.1

49.9

42.1

45.5

S. D.

1.86

2.58

2.00

1.21

1.91

1.50

1.14

2.58

2.13

2.29

.97

1.74

1.76

C.

4.1

5.5

3.7

2.8

3.7

4.1

2.6

5.2

4.8

5.0

1.9

4.1

3.9

Dec. 8...

R.

M.

49.9

50.0

51.3

48.0

56.5

46.1

41.3

39.7

44.4

45.5

52.9

46.4

47.5

S. D.

1.47

.32

2.90

1.10

1.27

1.11

2.16

2.73

2.42

2.10

1.20

1.07

1.49

C.

2.9

0.6

5.7

2.3

2.2

2.4

5.2

6.9

5.5

4.6

2.3

2.3

3.3

L.

M.

46.4

44.1

53.3

40.3

48.4

36.1

42.2

50.8

42.7

43.4

46.2

40.9

43.8

S. D.

1.24

1.96

1.99

.82

2.44

2.80

3.20

2.42

1.03

1.20

2.40

.66

1.90

C.

2.7

4.4

3.7

2.0

5.0

7.8

7.6

4.8

2.4

2.8

5.2

1.6

4.4

Dec. 19...

R.

M.

51.2

51.1

53.8

51.6

54.6

41.2

44.0

43.0

43.3

..

50.1

44.9

47.6

S.D.

1.50

1.60

1.17

1.99

1.99

3.42

1.45

2.67

.52

..

1.80

.58

1.75

C.

2.9

3.1

2.2

3.9

3.6

8.3

3.3

6.2

1.2

..

3.6

1.3

3.7

L.

M.

43.6

39.2

53.2

43.8

44.9

34.3

40.4

49.0

42.8

..

46.4

38.6

42.3

S.D.

1.56

1.69

.68

1.66

2.35

.81

1.62

1.30

1.17

...

2.18

1.06

1.54

C.

3.6

4.3

1.3

3.8

5.2

2.4

4.0

2.7

2.7

..

4.7

2.7

3.6

1918

Jan. 12...

R.

M.

52.6

52.7

50.0

48.9

55.6

45.1

44.9

31.7

46.1

..

48.7

44.8

47.1

S.D.

1.36

.60

4.66

.66

1.86

1.39

1.28

5.81

1.11

..

2.73

.59

1.74

C.

2.6

1.1

9.3

1.3

3.3

3.1

2.9

18.3

2.4

..

5. 6

1.3

4.2

L.

M.

44.7

45.5

54.0

43.1

48.5

39.5

40.7

54.4

49.1

..

45.8

40.2

45.2

S.D.

.60

2.53

3.36

1.16

1.90

1.34

.74

1.86

1.86

..

2.25

.81

1.51

C.

1.3

5.6

6.2

2.7

3.9

3.4

1.8

3.4

3.8

..

4.9

2.0

3.3

Jan. 26...

R.

M.

52.7

52.1

55.7

51.2

52.4

44.3

45.0

44.0

43.1

...

48.9

45.5

47.9

S.D.

1.25

1.36

1.21

1.47

2.44

1.72

1.42

2.28

.76

..

1.02

.45

1.42

C.

2.4

2.6

2.2

2.9

4.7

3.9

3.2

5.2

1.8

..

2.1

1.0

3.0

L.

M.

46.8

46.6

55.2

43.9

46.7

36.8

40.7

48.3

44.2

..

43.8

40.8

43.9

S.D.

.25

1.96

.68

1.02

1.94

1.29

1.66

2.60

.87

..

1.08

1.03

1.37

C.

.5

4.2

1.2

2.3

4.2

3.5

4.1

5.4

2.0

..

2.5

2.5

3.1

Feb. 2...

R.

M.

53.2

51.2

57.9

47.7

56.3

38.4

44.6

45.6

41.7

..

49.9

46.2

47.5

S.D.

.51

1.75

1.28

1.12

2.04

1.77

1.63

1.53

.98

..

1.20

1.57

1.41

C.

1.0

3.4

2.2

2.3

3.6

4.6

3.7

3.4

2.3

..

2.4

3.4

3.0

L.

M.

46.0

48.4

55.7

38.4

50.7

34.5

43.7

48.8

41.2

...

47.4

41.6

44.1

S.D.

.89

1.99

1.17

1.24

1.17

1.64

3.08

1.43

2.23

..

1.50

2.62

1.78

C.

2.0

4.1

2.1

3.2

2.3

4.8

7.1

2.9

5.4

...

3.2

6.3

4.1

Low-diet av.

R..

M.

51.6

54.0

55.4

49.6

56.6

42.5

44.5

41.6

44.8

46.6

49.9

45.4

48.1

L.

M.

45.3

47.6

54.8

42.7

49.5

36.0

42.1

50.3

45.5

46.5

46.5

41.1

44.7

May 212 . .

R.

M.

51.0

57.5

..

..

..

..

52.6

50.8

...

47.5

• • • • •

51.9

51.9

S.D.

1.92

.71

..

..

..

..

1.54

4.06

.....

1.70

.....

.58:

17.5

C.

3.8

1.2

..

..

..

..

2.9

8.0

.. • •.

3.6

• • • •

1.1

2.1

L.

M.

45.8

53.9

..

..

..

..

52.4

55.7

...

48.1

• • •

46.1

50.3

S.D.

1.72

1.16

...

..

..

..

3.64

1.64

.....

2.62

.....

2.22

21.7

C.

3.8

2.2

..

..

..

..

6.9

2.9

.....

5.4

.....

4.8

2.6

1R. and L. are for right and left hands; M., mean or average; S. D., standard deviation; C, coefficient of variability. Taken in Springfield.

Table 162. - Squad B - Strength Of Grip At Evening Sessions

[Values in kilograms]

Date.

Hand.

Fis.

Har.

How.

Ham.

McM.

Kim.

Lon.

Mao.

Sch.

Liv.

Sne.

Tho.

Van.

Wil.

Av.

1917.

Nov. 3

R.

M.

57.3

49.7

61.4

50.5

47.4

..

54.0

60.0

..

48.0

60.7

50.4

55.5

56.8

54.4

3.D.

2.34

1.21

3.79

2.24

1.62

..

3.24

.63

..

1.30

2.71

1.19

2.66

2.01

2.27

C.

4.1

2.4

6.2

4.4

3.6

..

6.0

1.1

..

2.7

4.5

2.4

4.8

3.5

4.2

L.

M.

52.4

49.1

54.7

48.3

42.2

..

48.2

54.7

..

45.2

60.5

46.9

57.7

49.6

51.3

3.D.

3.22

3.34

2.52

1.89

1.12

...

3.15

1.78

..

1.36

2.76

2.29

.51

1.93

2.30

C.

6.1

6.8

4.6

3.9

2.7

..

6.5

3.3

..

3.0

4.6

4.9

0.9

3.9

4.5

Nov. 17

R.

M.

57.5

52.0

61.8

48.7

48.3

..

58.1

58.0

..

46.2

64.4

57.1

60.9

52.5

55.9

9.D.

1.41

2.59

3.61

2.87

1.22

..

2.31

2.10

..

1.21

.58

1.02

.66

3.80

2.01

C.

2.5

5.0

5.8

5.9

2.5

..

4.0

3.6

..

2.6

0.9

1.8

1.1

7.2

3.6

L.

M.

56.8

51.5

53.6

45.1

38.9

..

54.1

53.8

..

45.5

63.2

51.2

57.0

49.0

52.7

3.D.

1.03

2.02

2.22

2.18

1.07

..

1.32

1.72

..

1.48

1.69

1.47

.84

3.93

1.82

C

1.8

3.9

4.1

4.8

2.8

....

2.4

3.2

..

3.3

2.7

2.9

1.5

8.0

3.5

Dec. 15

R.

M.

..

49.0

64.2

47.4

49.5

..

60.6

58.2

..

46.9

60.6

55.6

58.4

53.5

55.1

3.D.

.....

2.28

1.29

3.57

1.27

..

3.60

2.20

..

.86

1.20

1.32

1.80

1.92

1.98

C.

..

4.7

2.0

4.7

2.6

..

5.9

3.8

..

1.8

2.0

2.4

3.1

3.6

3.6

L.

M.

..

50.8

59.2

44.9

40.7

..

51.7

53.0

..

47.0

59.2

48.7

43.5

51.8

50.6

S.D

..

3 14

2 20

2 20

1 03

..

1 91

2 28

..

71

2 80

1 89

1 95

3 44

2 25

C.

..

6.2

3.7

4.9

2.5

..

3.7

4.3

..

1.5

4.7

3.9

4.5

6.6

4.4

1918.

Jan. 5

R.

M.

58.4

49.0

62.9

51.8

52.7

47.8

..

..

54.6

48.1

58.1

53.3

60.5

53.6

55.1

3.D.

.97

3.11

2.46

2.87

1.60

1.44

..

..

1.32

1.28

.80

2.94

1.84

1.39

1.96

C.

1.7

4.9

3.9

5.5

3.0

3.0

..

..

3.4

2.7

1.4

5.5

3.0

2.6

3.6

L.

M.

54.5

52.1

55.6

47.7

40.3

48.8

..

..

54.9

48.1

54.3

47.5

58.2

48.6

51.8

S.D.

1.38

2.11

1.36

.87

1.29

3.31

..

..

2.54

1.28

1.08

1.76

2.04

1.46

1.48

C.

2.5

4.1

2.4

1.8

3.2

6.8

..

..

4.6

2.7

2.0

3.7

3.5

3.0

2.9

Normal av...

R.

M.

57.7

49.9

62.6

49.6

49.5

47.8

57.6

58.7

54.6

47.3

61.0

54.1

58.8

54.1

55.1

L.

M.

54.6

50.9

55.8

46.5

40.5

48.8

51.3

53.8

54.9

46.5

59.3

48.6

54.1

49.8

51.6

Jan. 13

R.

M.

62.4

55.9

62.5

50.1

..

46.4

56.3

..

57.6

50.1

61.9

54.6

57.7

54.3

56.6

9.D.

.80

.66

2.95

1.28

..

2.31

2.38

..

1.24

1.16

2.01

1.50

2.13

1.54

1.64

C.

1.3

1.2

4.7

2.6

..

5.0

4.2

..

2.2

2.3

3.2

2.7

3.7

2.8

2.9

L.

M.

58.2

56.2

41.5

45.9

..

48.4

54.3

..

54.3

48.2

56 0

47.8

56.1

51.2

51.5

S.D.

.0.81

1.94

3.59

2.78

..

3.43

1.25

..

1.47

.98

1.87

1.86

.92

1.21

1.72

C.

1.4

3.5

8.7

6.1

..

7.1

2.3

..

2.7

2.0

3.3

3.9

1.6

2.4

3.3

Jan. 19

R.

M.

60.0

54.7

58.2

53.3

..

45.4

57.5

...

50.6

49.1

60.2

53.3

56.0

52.9

55.5

S.D.

1.55

1.17

3.67

.98

...

2.82

1.22

...

2.33

.66

.93

1.60

.55

2.42

1.48

C.

2.6

2.1

6.3

1.8

..

6.2

2.1

..

4.6

1.3

1.5

3.0

1.0

4.6

2.7

L.

M.

55.6

60.0

40.5

48.2

..

49.7

51.0

..

49.3

46.6

56.4

47.6

51.9

50.8

50.9

8.D.

3.37

1.92

3.35

1.89

..

2.31

1.67

..

1.12

.74

.86

2.35

1.80

2.23

2 02

C.

6,1

3.2

8.3

3.9

..

4.7

3.3

.

2 3

1.6

1.5

4.9

3.5

2.4

4.0

Jan. 27

R.

M.

62.2

55.5

58.7

52.1

..

47.0

56.7

..

53.2

48.2

58.6

56.0

60.0

53.7

56.2

8.D.

1.75

1.61

1.72

2.43

..

1.23

2.84

..

1.69

1.21

1.59

1.58

0.63

1.54

1.69

C.

2.8

2.9

2.9

4.7

..

2.6

5.0

..

3.2

2.5

2.7

2.8

1.0

2.9

3.0

L.

M.

57.9

55.9

37.9

45.4

...

48.4

49.8

..

53.4

45.7

55.4

50.2

54.2

50.6

50.3

8.D.

1.43

2.01

3.64

1.32

..

1.98

1.50

..

1.36

1.17

1.59

1.21

2.87

2.50

1.92

C.

2.5

3.6

9.6

2.9

..

4.1

3.0

..

2.5

2.6

2.9

2.4

5.3

4.9

3.8

Low-diet av...

R

M.

61.5

55.4

59.8

51.8

...

46.3

56.8

..

53.8

49.1

60.2

54.6

57.9

53.6

56.1

L.

M.

57.2

57.4

40.0

46.5

..

48.8

51.7

..

52.3

46.8

55.9

48.5

54.1

50.9

50.9

1R. and L. designate right and left hands; M., mean or average; S. D., standard deviation; and C, coefficient of variability.

The strength of grip data taken in the morning sessions are given in tables 163 and 164. This test was given in the same way as in the evening and with similar instructions. Averages are recorded for the 5 alternate trials with each hand. The standard deviation and coefficient of variability are also included for each average. It is unnecessary to comment upon the features of the individual data in these tables. In general they are consistent with those shown for the evening tests by the same subjects. The general average for the morning is definitely below that of the evening. In the case of Squad A the average for the right hand in the morning is 46.9 as compared to 48.1 kg. in the evening, and 43.3 as compared to 44.7 kg. in the evening with the left hand. With Squad B the normal average for the right hand in the morning is 52.9 and in the evening 55.1 kg. For the left hand it is 49.9 in the morning and 51.6 kg. in the evening. The low-diet averages also exhibit the same tendency: Right hand, morning, 52.7, evening, 56.1; left hand, morning, 47.5, evening, 50.9 kg. In general the morning results for strength of grip are 2 or 3 kilograms below those of the previous evening.