Table 1 Age and gender thresholds for study inclusion

Range of knee joint flexion

55-64 years

< 128°

< 127°

65-74 years

< 125°

< 122°

75+ years

< 120°

< 117°

Isometric quadriceps strength (kilograms force)

55-64 years

< 18.1

< 11.3

65-74 years

< 17.2

< 9.4

75+ years

< 13.9

< 9.0

Single-leg standing balance (seconds)

55-64 years

< 8

< 5

65-74 years

< 3

< 3

75+ years

< 2

< 2