SUPPLEMENTARY MATERIAL
Constructing an Index of Physical Fitness Age for Japanese Elderly Based on 7-year
Longitudinal Data: Sex Differences in Estimated Physical Fitness Age
Supplementary material: Detail of the battery of physical function tests for the elderly
Open-eyes or close-eyes one-leg stand tests (second): Standing time on one foot with opened eyes or closed eyes were measured in stopwatch. The subjects were instructed to stand barefoot, place the hands on the hip, do not let the legs touch each other, and do not let the standing foot move on the floor. The criteria to stop timing the test were the subject foot touched down the floor or touched the standing foot, the feet moved on the floor, or the arms moved from their start position.
Functional reach test (cm): Subjects were requested to stand up for standing straight, and to put the left arm to a side of the body, and to put up the right arm forward horizontally (basic posture). The subject lets a body bend forward as much as possible without putting up a heel. The distance between the finger-tip (right hand) with the basic posture and the finger-tip (right hand) with the test position was measured.
Chair stepping (numbers/20s): Subjects were instructed to sit on a chair closing knee and hold the side of the chair with both hands, as the foot works easily. Two legs were put inside two parallel lines in the intervals 30 cm on the floor as the start position, and opened and closed so as not to step on the lines as fast as possible. The number was counted that the two legs attached inside the two lines without dragging the foot or stepping on the lines in 20 seconds.
Sit-and-reach test (cm): Subjects were instructed to sit on floor with shoes off, attaching their hip, back, and occipital region of the head to a wall, with legs held straight by a digital flexibility testing device (TKK5112; Takei Scientific Instruments, Nigata, Japan). The device displays the distance which the device moved. They put both hands on the device, with arms held straight. In the position, zero point of the device was set. They were then asked to bend forward slowly and reach as far forward as possible. The better of two trials was recorded.
Leg strength (kg): The maximal muscle isometric strength was measured in the sitting position on a custom-made dynamometer chair at a knee angle of 90°. The ankle was attached to a strain-gauge system via belts around the pelvis and shoulders. After familiarization with the test, subjects were encouraged to produce maximal knee extension force. Three maximal efforts, separated by a 1-min rest period, were conducted, and the highest recorded value was accepted as the result.
Grip strength (kg): Hand-grip strength was measured by using a Smedley Hand Dynamometer (Grip-D, TKK5101; Takei Scientific Instruments, Nigata, Japan). When performing the measurement, subjects were instructed to maintain the standard bipedal position during the entire test with the arm in complete extension and not to touch any part of the body with the dynamometer except the hand being measured. The width of the handle was adjusted, so that, when the subject held the dynamometer, the second phalanx was against the inner stirrup. Two trials, with brief pauses, were allowed for each hand alternately. Subjects were encouraged to exert their maximal grip.
Vertical jump test (cm): Vertical jump test performed on a specially designed measuring scale (Jump Meter-MD, TKK5106; Takei Scientific Instruments, Nigata, Japan). Each subject performed two maximal jumps with counter movement of lower limbs. A trained investigator supported the participant after landing if they were likely to lose balance. The participants were given several familiarization trials before the test.
Shuttle stamina walk test (SSTw, meters): This test was assessed as the distance of fast walking around two poles placed 10 meters apart in a 3-minute period. Instructions given were: 1) Try to walk as fast as possible, and 2) walk around the pole in small steps at each turn. One maximal effort was conducted.
6-m walk (speed, m/sec), 6-m walk (footstep, cm), and 10-m walk (sec) tests: Participants were instructed to walk 10 m at their normal, comfortable pace to determine their habitual gait velocity and then told to walk as fast as they could to determine their maximal gait velocity. The walking time was measured using a digital stopwatch at the distance of six meters after initial two meters of acceleration and before last two meters of deceleration. The speed was calculated as 6-m divided by the walking time. The step counts and time between the first and final steps of the 6-m were also recoded, and the footstep was calculated as the value that divided the walk speed by steps. The total time of the 10-m walk was also recorded.
Chair stand test (frequency/30s): This test was measured as subjects stood up and sat down as quickly as possible on a firm, padded, armless chair with a seat that was 0.43 m from the ground. The back of the chair was supported against a wall, and subjects were instructed to fold their arms across their chest during the test. The number of repetitions over a period of 30 s was recorded.