Variation on the Torque on Knee Experiment
Response: Torque on knee (Newton meters, Nm)
Conditions: Feet Neutral, Feet Back, Feet Staggered
Material: 45 older men with Total Knee Arthroplasty (TKA)
Form five (5) blocks of nine (9) men by sorting according to the men’s body mass index
(BMI). A larger BMI indicates that a person is heavier for his height and a smaller BMI
indicates that a person is lighter for his height. A BMI of 30 or above indicates that a
person is obese. A BMI less than 18.5 indicates that a person is underweight.
Randomization:
Within each block, randomly assign 3 men to each of the conditions.
Data:
Block
1
15  BMI  18
2
18  BMI  21
3
21  BMI  24
4
24  BMI  27
5
27  BMI  30
Mean
Feet Neutral
21.4
17.4
18.4
22.7
21.1
22.5
25.6
22.8
23.0
26.3
25.9
26.1
29.6
27.4
31.3
24.1
Feet Back
18.8
17.7
17.3
19.7
20.0
19.9
21.1
21.9
22.2
23.0
23.3
23.4
25.5
23.2
28.5
21.7
Feet Staggered
19.0
16.6
18.6
19.8
19.5
19.6
18.5
20.0
22.1
21.3
22.4
22.5
21.8
22.3
26.5
20.7
Response: Torque
Summary of Fit
RSquare
RSquare Adj
Root Mean Square Error
Mean of Response
Observations (or Sum Wgts)
0.833901
0.807674
1.483338
22.16667
45
1
Analysis of Variance
Source
DF Sum of Squares
Model
6
419.76889
Error
38
83.61111
C. Total
44
503.38000
Lack Of Fit
Source
Lack Of Fit
Pure Error
Total Error
DF
8
30
38
Effect Tests
Source
Nparm
Method
2
Block
4
Mean Square
69.9615
2.2003
Sum of Squares
20.597778
63.013333
83.611111
DF
2
4
F Ratio
31.7964
Prob > F
<.0001*
Mean Square
2.57472
2.10044
Sum of Squares
91.60000
328.16889
F Ratio
20.8154
37.2870
F Ratio
1.2258
Prob > F
0.3183
Max RSq
0.8748
Prob > F
<.0001*
<.0001*
Effect Details
Method
LSMeans Differences Student's t
α=0.050 t=2.02439: LSD = 2.02439*(0.54164) = 1.096
LSMean[i] By LSMean[j]
Mean[i]-Mean[j]
Std Err Dif
Lower CL Dif
Upper CL Dif
B
N
S
Level
N
B
S
A
B
B
B
N
S
0
0
0
0
2.4
0.54164
1.30351
3.49649
-1
0.54164
-2.0965
0.09649
-2.4
0.54164
-3.4965
-1.3035
0
0
0
0
-3.4
0.54164
-4.4965
-2.3035
1
0.54164
-0.0965
2.09649
3.4
0.54164
2.30351
4.49649
0
0
0
0
Least Sq Mean
24.100000
21.700000
20.700000
Levels not connected by same letter are significantly different.
2