SHORT COMMUNICATON
Nagoya J. Med. Sci. 83. 841–850, 2021
doi:10.18999/nagjms.83.4.841

Relationship of frequency of participation in a physicalcheckup and physical fitness in middle-aged and elderly
people: the Yakumo study
Kazuyoshi Kobayashi1, Kei Ando1, Hiroaki Nakashima1, Masaaki Machino1,
Shunsuke Kanbara1, Sadayuki Ito1, Taro Inoue1, Hidetoshi Yamaguchi1,
Hiroyuki Koshimizu1, Naoki Segi1, Yukiharu Hasegawa2
and Shiro Imagama1
1

Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan2
Department of Rehabilitation, Kansai University of Welfare Science, Kashiwara, Japan

ABSTRACTAn annual physical checkup is provided as part of the long-term Yakumo study. The checkup isvoluntary and there is variation in the frequency of participation. The aim of this study was to examine
relationship of physical fitness with frequency of participation in this checkup. The subjects had all attended
at least one annual physical checkup from 2006 to 2018. Data from 1,804 initial checkups were used foranalysis. At the checkups, age, gender, height, weight, body mass index (BMI), and bone mineral density(BMD) were recorded, and physical activity was measured. The average number of physical checkups per
participant for 13 years was 2.4 (1–13). Daily exercise habits were found to be significantly associatedwith higher participation in physical checkups. Furthermore, between groups with low (1–5 times; <90thpercentile of participants) and high (≥6 times) participation, weight and BMI were significantly higher, and
BMD, grip strength, 10-m gait time, back muscle strength, and two-step test were all significantly lower
in the group with lower frequency of participation in the checkup. In conclusions, our results show thatfrequency of participation in a voluntary annual physical checkup is significantly associated with physicalfitness in middle-aged and elderly people.
Keywords: annual physical checkup, frequency of participation, middle-aged and elderly people, physicalperformance, Yakumo study
Abbreviations:
BMI: body mass index
BMD: bone mineral density
This is an Open Access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
License. To view the details of this license, please visit (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Received: November 9, 2020; accepted: March 9, 2021
Corresponding Author: Kazuyoshi Kobayashi, MD
Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho,Showa-ku, Nagoya 466-8550, Japan
TEL: +81-52-741-2111, Fax: +81-52-744-2260, E-mail: kobakazu@med.nagoya-u.ac.jp
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INTRODUCTION
Approaches for keeping elderly people healthy are needed due to aging of Japanese society
and in anticipation of upcoming aging of societies worldwide. The population aged ≥65 years
has increased rapidly, with rates of 4.9%, 10.3%, 19.9%, and 26.0% in 1950, 1985, 2005, and2015, respectively.1 Furthermore, this rate is estimated to reach 30.1% in 2024 and 39.0% in
2051.2 These changes are likely to lead to higher costs for nursing care, and it may be difficult
to maintain a good quality of life (QOL) for all people.3 Therefore, prolongation of healthy
activities of daily living (ADL) is necessary from a government perspective, as well as being
useful for elderly people themselves.
Physical fitness is an important component of ADL and QOL, especially in middle-aged
and elderly people.4-6 In extension of healthy life expectancy, physical fitness is associated withprevention of lifestyle-related diseases,2 and a decrease in physical strength and physical activity
associated with aging can cause a large decrease in physical fitness.7 Sustained physical activity isimportant to maintain physical fitness, and acquisition of exercise habits may affect maintenanceand improvement of physical ability and acquisition of good lifestyle habits.8
We have conducted general screening of a residential cohort in Yakumo for many years. The“Yakumo study” includes an annual physical checkup, in which a prospective cross-sectional
examination of physical fitness in middle-aged and elderly people is performed.4-6 The municipal
government recommends that a physical checkup in middle-aged and elderly people shouldbe performed at least once every 5 years. However, as part of our long-term cohort study,
participation in a physical checkup is voluntary and there may be variation in the frequency ofparticipation. This allows an examination of the relationship of physical fitness with frequencyof participation in physical checkups, which has not been previously evaluated. Previously, in alongitudinal study, we found that physical fitness with aging had improved in a current population compared with these functions in a similar population from 15 years ago.9 However, therelationship of physical fitness with frequency of participation in physical checkups has not been
evaluated. Therefore, the purpose of this study was to examine this relationship in middle-aged
and elderly people. Understanding the significance of the frequency of participation in physicalcheckups may help in efforts to improve physical fitness.

MATERIALS AND METHODS
We have performed a cohort study in Yakumo for 35 years, in which a physical checkup has
been held as an adjunct to a general public health checkup. The subjects were all participants
who underwent an annual physical checkup in the Yakumo study for 13 years from 2006 to2018. This checkup is performed annually in Yakumo, which is located in Hokkaido, in the northof Japan every August for four days. Medical examinations are offered to all residents aged 40
and over, and physical checkups are conducted for those want them. The municipal government
recommends a physical checkup in middle-aged and elderly people at least once every 5 years,
but participation is voluntary. Subjects who participated in the physical checkup at least oncefrom 2006 to 2018 were identified, and the number of times each subject participated and theresults of their first physical fitness test were examined in this study. The total number of annual
physical checkups by gender and the average age of participants are shown in Figure 1. Over13 years, 4,349 physical checkups were performed in 1,804 participants. Background factors ofage, gender, height, weight, body mass index (BMI), and bone mineral density (BMD) were also
recorded. The inclusion criteria were Japanese males and females aged >40 years who underwent

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Physical checkup and physical fitness

Fig. 1 Trends of physical checkups and average age
Number of physical checkups by gender (bar graph) and average age of participants (line graph). A total of
4,349 physical checkups were performed.

the physical examinations described below during the basic health checkup.10,11 Individuals were
excluded if they had severe walking or standing disabilities or dysfunction of the central or
peripheral nervous systems. Analysis was conducted from October to December 2019.
The frequency of participation in annual physical checkups was determined for all participants,
and compared with their physical fitness. For a participant who attended the checkup more thanonce, only initial checkup data were included in the study. Of the 4,349 checkups, 2.545 were
excluded as second or later checkups, leaving data from 1,804 initial checkups for analysis.
Thus, these 1,804 participants are people who have undergone a physical checkup at least once.
Participants were categorized in groups based on participation 1–5 times (<90th percentile ofparticipants) and ≥6 times (≥90th percentile). Regarding exercise habits, an interview by questionnaire was performed. For weekly exercise, information was obtained on the type of exercise,frequency per week, exercise time, and intensity of exercise. The subjects were divided into
an exercise group (Ex (+)) and a group (Ex (–)) comprising those with mild physical activity(such as walking or a physical hobby) of over 2 h per week and light physical activity (without
shortness of breath).12,13 The subjects were asked to answer “yes” or “no” to having “at least mild
physical activity of over 2 h per week”. All participants provided written informed consent. The
study protocol was approved by the Institutional Review Board of Nagoya University Graduate
School of Medicine (No. 2014-0207), and the procedures were carried out in accordance withthe principles of the Declaration of Helsinki.
Physical measurements
Bone mineral density (BMD) was measured ultrasonically in the calcaneus using a bonedensitometer (A1000 Insight, Lunar Corp., Madison, WI, USA), and the percent of the young
adult mean (%YAM) was measured.14,15 For physical fitness, grip strength was measured in astanding position using a Toei Light hand-grip dynamometer (Toei Light Co., Ltd., Saitama,
Japan). Measurements were made twice, with the left and right upper limbs hanging at the side

844
Kazuyoshi Kobayashi et alof the body. Grip strength was obtained for each hand, and the average was used in the analysis.16
The 10-m gait time was measured to evaluate mobility, as the time required to complete a 10-m
straight course at the fastest pace possible for each subject. Subjects performed the test twice,both at maximum pace, and the mean time was used for analysis.10 For back muscle strength,
the maximum isometric strength of the back extensor muscles was measured in a standing position with lumbar flexion of 30° and knees extended using a digital T.K.K. 5102 dynamometer(Takei Co., Tokyo, Japan). The average force from two trials was recorded, and the maximum
strength in each trial was measured. The two-step test was performed in a standing position.
Subjects placed their right foot forward as far as possible and then brought their left foot up
to the right foot without support. The maneuver was then repeated with the left foot stepping
forward first. The test was performed twice, and the average step length divided by the heightof the subject was used as the two-step test for analysis.17 All physical measurements were madeby 10 orthopedic surgeons.
Statistical analysis
Differences between two groups were analyzed by Mann-Whitney U test, and Pearson chisquare test. SPSS ver. 25 for Windows (IBM, Chicago, IL) was used for all analyses, with
p<0.05 considered to be significant.

RESULTSFor 13 years from 2006 to 2018, 1,804 participants underwent a total of 4,349 physicalcheckups. The participants included 686 males and 1,118 females, and had an average age of
62.9 (40–91) years. Further demographic data are shown in Table 1. The average number ofcheckups per participant was 2.4 (1–13) in 13 years, based on participation in 1 (n=963), 2(n=327), 3 (n=163), 4 (n=95), 5 (n=63), 6 (n=54), 7 (n=42), 8 (n=33), 9 (n=17), 10 (n=17), 11(n=19), 12 (n=9) and 13 (n=2) checkups (Figure 2). There was no significant difference in thenumber of checkups per participant by gender.

Table 1

Demographic and physical fitness data for all participants (n=1,804)

Total(n=1,804)

VariableMale(n=686)

Female(n=1,118)

Demographic
Age (years)

62.8±10.564.5±10.0

61.7±10.7

Height (cm)156.8±8.4163.9±6.4152.3±6.2

59.0±11.1

65.9±10.754.6±8.9

Weight (kg)Body mass index (kg/m )23.8±3.924.5±3.4

23.5±3.6

Bone mineral density (%YAM)

80.6±17.482.1±16.6

79.8±18.7

2

Physical fitness
Grip strength (kg)29.2±9.3

38.0±7.8

23.8±5.1

10-m gait time (sec)

5.6±2.1

5.4±2.4

5.7±1.8

Back muscle strength (kg)72.1±34.0

97.5±28.6

55.7±17.7

Two-step test

1.38±0.21

1.39±0.20

1.37±0.19

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Physical checkup and physical fitness

Fig. 2 Trends of number of physical checkups
Number of participants per physical checkups. Participants were categorized as having low (1–5 times, <90thpercentile of participants) or high (≥6 times, ≥90th percentile) participation in physical checkups.

In groups with low (1–5 times) and high (≥6 times) participation, there was no significant
differences in age or height for males and females. However, there were significant differences
between these groups for weight (males: 66.3 vs. 63.3 kg; females:54.7 vs. 53.1 kg), BMI (24.6
vs. 23.4 kg/m2; 23.6 vs. 23.1 kg/m2), BMD (81.5% vs. 85.6%; 79.6% vs. 81.2%), grip strength(37.8 vs. 39.4 kg; 23.6 vs. 25.5), 10-m gait time (5.3 vs. 4.9 s; 5.8 vs. 5.2 s), back muscle
strength (96.3 vs.102.3; 55.5 vs. 59.9 kg), and two-step test (1.38 vs. 1.49; 1.37 vs. 1.44) (Table
2). A comparison of subjects with and without exercise habits is shown in Figure 3. The Ex(+)
and Ex (–) groups included 288 (42%) and 398 (58%) participants, respectively. There was asignificantly higher percentage of Ex(+) subjects with a high number of physical checkups (≥6times) (p<0.01) (Figure 3).

Table 2

Data for males and females with low (1–5 times) and high (≥6 times) rates of participation inphysical checkups

Variables
Male (n=686)

Low(1–5 times)High(≥6 times)(n=611)(n=75)

p value

Demographic
Age (years)

64.5±10.864.3±6.7

n.s.

Height (cm)

168.3±6.5

164.5±5.6n.s.

66.3±11.1

63.3±7.3<0.01

Body mass index (kg/m )24.6±3.523.4±2.3<0.01

Bone mineral density (%YAM)

81.5±16.4

85.6±16.6<0.05

Grip strength (kg)37.8±7.939.4±6.9<0.01

10-m gait time (sec)5.3±1.1

4.9±0.8<0.01

Back muscle strength (kg)96.3±27.8

102.3±26.6<0.05

Weight (kg)2

Physical fitness

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Kazuyoshi Kobayashi et al

Two-step test

1.38±0.21

1.49±0.15<0.01

Female (n=1,118)(n=1000)(n=118)Age (years)

61.7±10.562.0±7.1

n.s.

Height (cm)152.4±6.3

151.5±4.9n.s.

Weight (kg)54.7±9.1

53.1±7.1<0.05

Body mass index (kg/m2)

23.6±3.723.1±2.9<0.05

Bone mineral density (%YAM)

79.6±16.6

81.2±12.5<0.05

23.6±5.1

25.5±4.8<0.01

Demographic

Physical fitness
Grip strength (kg)
10-m gait time (sec)

5.8±3.5

5.2±0.8<0.01

Back muscle strength (kg)55.5±18.2

59.9±15.4<0.01

Two-step test

1.37±0.20

1.44±0.15<0.01

Fig. 3 Relationship between exercise habit and participation in physical checkups
There was a significantly higher percentage of Ex(+) subjects with a high number of physical checkups (≥6times) (p<0.01).

DISCUSSION
With current aging of society, health problems of the elderly are important issues in Japan.
Aging of the population has led to increased prevalences of various diseases, and this situation
places a focus on physical function, which is strongly associated with ADL and QOL in theelderly population.12,18-20 In 2007, the Japanese Orthopaedic Association proposed the concept of847
Physical checkup and physical fitness“locomotive syndrome”, as a condition in people with musculoskeletal disease who are highly
likely to require future nursing care.21,22 People with locomotive syndrome have significantly
lower ADL and QOL,23 and maintaining and improving physical fitness of middle-aged andelderly people may prevent locomotive syndrome.22,24-27 In addition, endurance physical fitness
and exercise habits are required to prevent metabolic syndrome and ischemic vascular disease. 28,29
However, there are few prospective studies of physical fitness.
We have performed a cohort study in Yakumo for 35 years, in which a physical checkup has
been held as an adjunct to a general public health checkup. Thus, the data in the current study
were obtained in conjunction with medical checkups for internal medicine, otolaryngology, urology, and orthopedics, which indicates that the physical checkup can be performed with cooperation of local governments. In the town of Yakumo, the participants were healthy middle-aged andelderly people who lived in a relatively rural area, and many had jobs in agriculture or fishing.
Relatively few people move into or out of the area. The municipal government recommends aphysical checkup in middle-aged and elderly people at least once every 5 years. However, thischeckup is voluntary, and some people participate every year, while others attend once every few
years. Therefore, the frequency of participation varies. This provided an opportunity to examine
the relationship of physical fitness with frequency of participation in the checkup.
The results of the study showed that people with more frequent participation in the annual
physical checkup had significantly higher physical fitness, including grip strength, 10-m gait time,back muscle strength, and two-step test. These results suggest the following points. 1) Participants
with high initial measurement values and confidence in their physical strength may be happy
to continue with participation in physical checkups, but those with low initial values may havedecreased motivation. 2) Participants who train well (people with exercise habits) are more likely
to participate in physical fitness tests frequently to see the effects. 3) People with high healthconsciousness may also have physical strength and may more often participate in a physicalcheckup. Especially, middle-aged and elderly people who participated in a physical checkup morethan once every 5 years might have greater health awareness, regardless of age or gender, andthis might have led to maintenance and improvement of physical fitness. For middle-aged andelderly people, maintenance of strength may provide the independence necessary to participate
in organized social activities.30 Physical and social environmental factors may also affect physicalactivity.31 Therefore, it may be that middle-aged and older people with a higher level of healthconsciousness might have more frequently participated in the annual physical checkup. BMD
was also significantly higher in more frequent participants, and exercise and physical activities
have been recognized as significant factors that reduce the risk of osteoporosis.32 Exercise may
help to maintain muscle strength, muscle volume, balance, and joint flexibility, and high-impact
and/or weight-bearing exercise may increase bone density in elderly people.33 These findings
may reflect our results showing a significant relationship between frequency of participation ina physical checkup and physical fitness.
The current study has some limitations. First, the annual physical checkup is voluntary and is
not required for any purpose. Thus, the number of checkups attended varied widely. Second, we
did not examine medical history, content of exercise, work history, and details of medication of
the participants. Also, the physical fitness examination does not include endurance, instantaneous
power, balance, and flexibility, and only physical checkup data were examined for the initialcheckup. In addition, it was not possible to investigate the health awareness of the participants.
Thus, we cannot rule out confounding effects, and multivariate analysis was not performed. Third,
it was not possible to examine the participation rate in the checkup in terms of the number ofresidents in the entire town. In addition, the relocation of residents in 13 years was not taken
into consideration at the time of the survey. Fourth, the physical checkup in this study is a

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Kazuyoshi Kobayashi et al

limited physical fitness test focusing only on muscular strength and walking ability, which reflect
conditions such as sarcopenia and frailty, and this may not detect high physical fitness directly.
However, this is the first study to show a relationship between the frequency of participation ina physical checkup and physical fitness in a long-term prospective study. The results also showedthat exercise habits are linked to frequent participation in physical checkups, and this may leadto improved physical fitness. It is important to increase the number of participants in the overall
physical checkup in the future, and we are working towards this goal.
In conclusion, middle-aged and elderly people with high exercise habits had higher physicalfitness and more frequently participated in a physical checkup. The frequency of participation in
a voluntary annual physical checkup (at least once every two years) was significantly associatedwith higher physical fitness in middle-aged and elderly people. Those who frequently participatedin physical checkups associated with sarcopenia and frailty also had better associated physicalfitness and exercise habits. This may be because people with higher physical fitness also havehigher health consciousness, which might have led to greater participation in checkups. Exercise
habits might also have influenced our results.

DISCLOSURE STATEMENT
Financial support was from institutional sources only. None of the authors have a conflict ofinterest to declare.

REFERENCES
1

2

3
4

5

6

7
8
9
10

11

Statistical Bureau, Ministry of Internal Affairs and Communication. Population Count based on the 2015 Census Released [in Japanese]. http://www.e-stat.go.jp/SG1/estat/GL08020101.do? _toGL08020101_&tstatCode=requestSender=dsearch.
Yoshimura N, Akune T, Fujiwara S, et al. Incidence of disability and its associated factors in Japanese men
and women: the Longitudinal Cohorts of Motor System Organ (LOCOMO) study. J Bone Miner Metab.
2015;33(2):186–191. doi:10.1007/s00774-014-0573-y.
Freedman VA, Crimmins E, Schoeni RF, et al. Resolving inconsistencies in trends in old-age disability:
report from a technical working group. Demography. 2004;41(3):417–441. doi:10.1353/dem.2004.0022.
Imagama S, Ando K, Kobayashi K, et al. Differences of locomotive syndrome and frailty in communitydwelling middle-aged and elderly people: Pain, osteoarthritis, spinal alignment, body balance, and qualityof life. Mod Rheumatol. 2020;30(5):921–929. doi:10.1080/14397595.2019.1665616.
Imagama S, Ando K, Kobayashi K, et al. Multivariate analysis of factors related to the absence of musculoskeletal degenerative disease in middle-aged and older people. Geriatr Gerontol Int. 2019;19(11):1141–1146.
doi:10.1111/ggi.13786.
Imagama S, Ando K, Kobayashi K, et al. Risk factors for neuropathic pain in middle-aged and elderly
people: a five-year longitudinal cohort in the Yakumo study. Pain Med. 2020;21(8):1604–1610. doi:10.1093/
pm/pnaa036.
Koishi M, Umezdu N, Ogasawara T,et al. Health and Social activity in the elderly [in Japanese]. Jpn Health
Med Assoc. 2002;11(1):13–18. doi:10.20685/kenkouigaku.11.1_13.
Kawano T, Yoshida D, Bono S, Miki Y, Yamasaki M. Relation between the health and exercise habits ofthe elderly [in Japanese]. J Socio-information Studies. 2016;21:43–49.
Kobayashi K, Ando K, Nakashima H, et al. Overcoming locomotive syndrome: The Yakumo Study. Mod
Rheumatol. 2021;31(3):750–754. doi:10.1080/14397595.2021.1879413.
Imagama S, Ando K, Kobayashi K, et al. Shoulder pain has most impact on poor quality of life among
various types of musculoskeletal pain in middle-aged and elderly people: Yakumo study. Mod Rheumatol.
2020;30(3):568–572. doi:10.1080/14397595.2019.1623364.
Imagama S, Ando K, Kobayashi K, et al. The relationship between neuropathic pain and spinal alignment:
independent risk factors for low quality of life in middle-aged and elderly people. Spine (Phila Pa 1976).

849
Physical checkup and physical fitness

12

13

14
15

16

17

18

19

20

21
22
23

24

25
26

27

28

29

30
31
32

2019;44(19):E1130–E1135. doi:10.1097/BRS.0000000000003073.
Imagama S, Hasegawa Y, Matsuyama Y, et al. Influence of sagittal balance and physical ability associatedwith exercise on quality of life in middle-aged and elderly people. Arch Osteoporos. 2011;6(1–2):13–20.
doi:10.1007/s11657-011-0052-1.
Hu G, Barengo NC, Tuomilehto J, Lakka TA, Nissinen A, Jousilahti P. Relationship of physical activity andbody mass index to the risk of hypertension: a prospective study in Finland. Hypertension. 2004;43(1):25–30.
doi:10.1161/01.HYP.0000107400.72456.19.
Kobayashi K, Ando K, Tsushima M, et al. Predictors of presarcopenia in community-dwelling older adults:
A 5-year longitudinal study. Mod Rheumatol. 2019;29(6):1053–1058. doi:10.1080/14397595.2018.1551171.
Kobayashi K, Imagama S, Ando K, et al. Epidemiology and effect on physical function of osteosarcopenia
in community-dwelling elderly people in Japan. Mod Rheumatol. 2020;30(3):592–597. doi:10.1080/143975
95.2019.1623455.
Kobayashi K, Imagama S, Ando K, et al. Weakness of grip strength reflects future locomotive syndrome and progression of locomotive risk stage: A 10-year longitudinal cohort study. Mod Rheumatol.
2020;30(3):573–579. doi:10.1080/14397595.2019.1626068.
Kobayashi K, Ando K, Tsushima M, et al. Predictors of locomotive syndrome in community-living people:
a prospective five-year longitudinal study. Mod Rheumatol. 2019;29(4):669–675. doi:10.1080/14397595.201
8.1514705.
Imagama S, Hasegawa Y, Wakao N, Hirano K, Hamajima N, Ishiguro N. Influence of lumbar kyphosisand back muscle strength on the symptoms of gastroesophageal reflux disease in middle-aged and elderly
people. Eur Spine J. 2012,21(11):2149–2157. doi:10.1007/s00586-012-2207-1.
Imagama S, Hasegawa Y, Wakao N, Hirano K, Muramoto A, Ishiguro N. Impact of spinal alignment andback muscle strength on shoulder range of motion in middle-aged and elderly people in a prospective
cohort study. Eur Spine J. 2014;23(7):1414–1419. doi:10.1007/s00586-014-3251-9.
Imagama S, Hasegawa Y, Ando K, et al. Staged decrease of physical ability on the locomotive syndrome risk
test is related to neuropathic pain, nociceptive pain, shoulder complaints, and quality of life in middle-aged
and elderly people: the utility of the locomotive syndrome risk test. Mod Rheumatol. 2017;27(6):1051–1056.
doi:10.1080/14397595.2017.1285856.
Nakamura K. A “super-aged” society and the “locomotive syndrome”. J Orthop Sci. 2008;13(1):1–2.
doi:10.1007/s00776-007-1202-6.
Nakamura K. The concept and treatment of locomotive syndrome: its acceptance and spread in Japan. J
Orthop Sci. 2011;16(5):489–491. doi:10.1007/s00776-011-0108-5.
Hirano K, Imagama S, Hasegawa Y, Ito Z, Muramoto A, Ishiguro N. The influence of locomotive syndromeon health-related quality of life in a community-living population. Mod Rheumatol. 2013;23(5):939–944.
doi:10.1007/s10165-012-0770-2.
Muramoto A, Imagama S, Ito Z, Hirano K, Ishiguro N, Hasegawa Y. Spinal sagittal balance substantiallyinfluences locomotive syndrome and physical performance in community-living middle-aged and elderly
women. J Orthop Sci. 2016;21(2):216–221. doi:10.1016/j.jos.2015.12.016.
Muramoto A, Imagama S, Ito Z, et al. Waist circumference is associated with locomotive syndrome inelderly females. J Orthop Sci. 2014;19(4):612–619. doi:10.1007/s00776-014-0559-6.
Hirano K, Imagama S, Hasegawa Y, Wakao N, Muramoto A, Ishiguro N. Impact of spinal imbalanceand back muscle strength on locomotive syndrome in community-living elderly people. J Orthop Sci.
2012;17(5):532–537. doi:10.1007/s00776-012-0266-0.
Muramoto A, Imagama S, Ito Z, Hirano K, Ishiguro N, Hasegawa Y. Physical performance tests are usefulfor evaluating and monitoring the severity of locomotive syndrome. J Orthop Sci. 2012;17(6):782–788.
doi:10.1007/s00776-012-0283-z.
Ogawa EF, Leritz E, McGlinchey R, Milberg W, Bean JF. Metabolic syndrome and physical performance: the moderating role of cognition among middle-to-older-aged adults. J Int Neuropsychol Soc.
2021;27(2):172–180. doi:10.1017/S1355617720000788.
McDermott MM, Greenland P, Tian L, et al. Association of 6-minute walk performance and physicalactivity with incident ischemic heart disease events and stroke in peripheral artery disease. J Am Heart
Assoc. 2015;4(7):e001846. doi:10.1161/JAHA.115.001846.
Damush TM, Damush JG Jr. The effects of strength training on strength and health-related quality of life
in older adult women. Gerontologist. 1999;39(6):705–710. doi:10.1093/geront/39.6.705.
Sallis JF, Hovell MF, Hofstetter CR. Predictors of adoption and maintenance of vigorous physical activity
in men and women. Prev Med. 1992;21(2):237–251. doi:10.1016/0091-7435(92)90022-a.
Yoshimura N. Exercise and physical activities for the prevention of osteoporotic fractures: a review of the850
Kazuyoshi Kobayashi et al33

evidence[in Japanese]. Jpn J Hygiene. 2003;58(3):328–337. doi:10.1265/jjh.58.328.
Motszko M. Preventing osteoporosis. Lifelong nutrition and exercise habits are the most powerful weapons.
Adv Nurse Pract. 2002;10(7):41–43,76.