Table 3 Retest reliability of measuring hip extensor muscle strength in different testing positions in young people with cerebral palsy (n = 19 left hips)

Lower

Upper

Group mean

Individual

Group mean

Individual

Standing

Trial 1

10.5 (5.6)

11.6 (6.3)

.64

.28

.84

1.1

5.07

-1.32 to 3.57

-9.53 to 11.78

34.9%

113.1%

Mean (trials 1&2)

10.9 (5.8)

12.9 (8.2)

.63

.28

.84

2.0

5.92

-0.72 to 4.99

-10.31 to 14.58

46.8%

134.8%

Mean (trials 2&3)

11.7 (6.5)

13.0 (7.9)

.75

.47

.89

1.3

5.09

-1.08 to 3.83

-9.33 to 12.07

33.0%

104.0%

Mean (trials 1-3)

11.3 (6.2)

12.5 (7.3)

.72

.42

.88

1.2

5.00

-1.12 to 3.70

-9.23 to 11.80

33.6%

105.3%

Maximum

12.6 (6.8)

13.9 (8.0)

.73

.43

.89

1.3

5.43

-1.28 to 3.95

-10.07 to 12.74

32.0%

101.5%

Prone

Trial 1

12.6 (7.4)

13.7 (8.7)

.83

.61

.93

1.0

4.70

-1.20 to 3.47

-8.74 to 11.01

28.3%

88.4%

Mean (trials 1&2)

12.9 (7.5)

13.5 (8.9)

.83

.60

.93

0.6

4.95

-1.89 to 3.04

-9.83 to 10.98

24.2%

85.8%

Mean (trials 2&3)

13.7 (8.0)

14.3 (8.8)

.75

.44

.90

0.6

6.08

-2.38 to 3.67

-12.13 to 13.42

27.6%

99.0%

Mean (trials 1-3)

12.6 (8.1)

13.6 (8.9)

.79

.54

.91

1.0

5.56

-1.69 to 3.68

-10.69 to 12.69

30.6%

101.5%

Maximum

14.6 (8.3)

14.7 (9.7)

.80

.53

.92

0.1

5.90

-2.82 to 3.05

-12.28 to 12.57

21.5%

86.3%

Supine

Trial 1

13.8 (6.7)

13.8 (6.9)

.55

.13

.80

0.0

6.52

-3.14 to 3.14

-13.70 to 13.70

23.6%

100%

Mean (trials 1&2)

15.3 (8.2)

13.7 (6.5)

.62

.26

.83

-1.6

6.34

-4.71 to 1.44

-15.04 to 11.77

10.0%

77.2%

Mean (trials 2&3)

15.7 (7.3)

13.9 (6.9)

.74

.45

.89

-1.8

4.94

-4.16 to 0.60

-12.15 to 8.59

4.3%

55.0%

Mean (trials 1-3)

15.1 (6.7)

13.9 (6.8)

.75

.46

.89

-1.2

4.78

-3.46 to 1.15

-11.20 to 8.89

8.1%

59.4%

Maximum

17.1 (7.7)

15.7 (7.9)

.78

.53

.91

-1.4

5.11

-3.87 to 1.05

-12.15 to 9.33

6.6%

54.8%