Clinical characteristics of locomotive syndrome categorised by the 25-question Geriatric Locomotive Function Scale: a systematic review

Abstract

Objectives

The purpose of this study was to compile the currently available evidence on the clinical characteristics of the locomotive syndrome (LS) categorised by the 25-question Geriatric Locomotive Function Scale (GLFS-25) and clarify its clinical usefulness for assessing mobility function.

Design

Systematic review.

Data sources

The PubMed and Google Scholar were searched for the relevant studies on 20 March 2022.

Eligibility criteria

We included relevant peer-reviewed articles, available in English language, on clinical LS characteristics categorised with the GLFS-25.

Data extraction and synthesis

Pooled ORs or mean differences (MDs) of the LS groups were calculated and compared with the non-LS groups for each clinical characteristic.

Results

In total, 27 studies that involve 13 281 participants (LS, n=3385; non-LS, n=9896) were examined in this analysis. Older age (MD 4.71; 95% (CI) 3.97 to 5.44; p<0.00001), female gender (OR 1.54; 95% CI 1.38 to 1.71; p<0.00001), higher body mass index (MD 0.78; 95% CI 0.57 to 0.99; p<0.00001), osteoporosis (OR 1.68; 95% CI 1.32 to 2.13; p<0.0001), depression (OR 3.14; 95% CI 1.81 to 5.44; p<0.0001), lower lumbar lordosis angle (MD −7.91; 95% CI −10.08 to −5.74; p<0.00001), higher spinal inclination angle (MD 2.70; 95% CI 1.76 to 3.65; p<0.00001), lower grip strength (MD −4.04; 95% CI −5.25 to −2.83; p<0.00001), lower back muscle strength (MD −15.32; 95% CI −23.83 to −6.81; p=0.0004), lower maximum stride (MD −19.36; 95% CI −23.25 to −15.47; p<0.00001), higher timed up-and-go (MD 1.36; 95% CI 0.92 to 1.79; p<0.00001), lower one-leg standing time (MD −19.13; 95% CI −23.29 to −14.97; p<0.0001) and slower normal gait speed (MD −0.20; 95% CI −0.22 to −0.18; p<0.0001) were found to be associated with LS. No significant differences were noted in other clinical characteristics between the two groups.

Conclusions

GLFS-25 is clinically useful for assessing mobility function according to the evidence available on the clinical characteristics of LS categorised by the GLFS-25 questionnaire items until.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This systematic review consisted of a comprehensive search on the articles related to the clinical characteristics of locomotive syndrome categorised by the 25-question Geriatric Locomotive Function Scale.

• We might have missed new publications or articles outside our search strategy, as this study area is growing rapidly in the elderly society.

• Since all the evidence included in this systematic review came from Japan, our findings might not be generalised globally.

Introduction

The ageing of the population in Japan has rapidly progressed over the past two decades.¹ Along with this ageing population, the number of people with musculoskeletal disorders that require long-term care has also rapidly increased.^1–3 Therefore, the Japanese Orthopaedic Association has disseminated the concept of ‘locomotive syndrome’ (LS) using its official categorical tool the 25-question Geriatric Locomotive Function Scale (GLFS-25) and management to prevent the physical function deterioration in the elderly (online supplemental figure 1).^1–4 The GLFS-25 was calibrated with 25 questionnaire items with 5 options for each item, which covered several domains including body pain (items 1–4), movement-related difficulty (items 5–7), usual care (items 8–11 and 14), social activities (items 12, 13 and 15–23) and cognition (items 24 and 25).^2–4 The total scores of 0–6, 7–15, 16–23 and 24–100 points are categorised with non-LS, LS-1, LS-2 and LS-3, respectively.^2–4 LS-1 is described as a state with declining mobility where developing the habit of exercising is needed to prevent LS severity progression and being categorised into LS (ie, LS-2 or more).^2–5 LS-2 is described as a state with progressively declining mobility where orthopaedic consultation is encouraged to prevent LS severity progression.^2–5 LS-3 is described as a state with declining mobility where social participation is hindered and surgical intervention for musculoskeletal disorders is considered to be effective to prevent LS severity progression.^2–5

The relationship between LS categorised by the GLFS-25 and various clinical characteristics (such as age, gender, body mass index, skeletal muscle mass index, osteoporosis, diabetes, depression, lumbar lordosis angle, spinal inclination angle, grip strength, back muscle strength, maximum stride, timed up-and-go, one-leg standing time and normal gait speed) has been investigated in previous studies,^6–47 which remains inconclusive. Although GLFS-25 includes some questionnaire items other than mobility function, its subjective assessment may be related to objective clinical characteristics, which are associated with mobility impairment. Recently, there has been extensive clinical research on the GLFS-25,^3–47 which requires a clarification regarding its clinical usefulness for assessing mobility function. By compiling the currently available evidence on this topic, we will be able to confirm the clinical usefulness of the GLFS-25 for assessing the mobility function.

Therefore, our review subsequently aims to clarify the following concerns: (1) clinical characteristics associated with LS categorised by the GLFS-25 and (2) clinical usefulness of GLFS-25 for assessing mobility function.

Materials and methods

For the description of this paper, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed.⁴⁸

Patient and public involvement

None.

Search strategy

PubMed and Google Scholar were searched for relevant peer-reviewed articles that are published in English language on clinical LS characteristics that are categorised with the GLFS-25. All searches were conducted on 20 March 2022. The search term used in PubMed includes the following: (Locomotive Syndrome [Title/Abstract]). Similarly, the search term used in Google Scholar was as follows: all-in-title “Locomotive Syndrome.” Grey literature, websites, organisations or reference lists of records that are identified through the database search were also screened. Articles that did not investigate the relationship between the GLFS-25 and physical performance tests and articles that were review articles, case reports (n<3), commentary, editorial, insights articles or proceedings were excluded.

Data extraction

Data were extracted on the included study (first author and publication year), study design, subject (inclusion criteria, age, gender, body mass index and LS incidence) and significant LS-related factors. As per previous studies,^21–47 it was found that the cut-off for LS assessment was GLFS scores of ≥16.

Quality assessment

The Newcastle-Ottawa Scale adapted for cross-sectional studies⁴⁹ was used to make a quality assessment of the included studies.

Risk of publication bias

The potential existence of publication bias was determined using the visual funnel plot.

Statistical methods

Statistical analyses were performed using Review Manager V.5.3 (The Cochrane Collaboration, Oxford, UK). Mean difference (MD) and 95% CI are used for the data processing of continuous outcomes. Mean value, SD and the number of subjects were then entered. ORs with 95% CI are used for binary outcome data processing. A number of events and subjects were entered. Heterogeneity analysis was performed using the p values and I² values in the χ² test. The random-effects model is applied when significant heterogeneity (I²≥50% and p<0.10) is found between the data. Contrarily, the fixed-effects model was used when no significant heterogeneity (I²<50% or p≥0.10) was found between the data.

Results

Search results

Figure 1 shows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram for our methodology. In total, 328 records (PubMed with 284 records online supplemental table 1; Google Scholar with 44 records online supplemental table 2 were identified through database searching, of which, 28 records were removed due to duplication. Accordingly, 300 records were individually screened through abstract, and 273 records were thereafter removed. Finally, 27 studies^21–47 that involve 13 281 participants (LS, n=3385; non-LS, n=9896) were determined eligible for this systematic review.

Figure 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram for our methodology.

Data of the included study

The information on included studies was summarised in table 1. All included studies were published in Japan with a cross-sectional design. The inclusion criteria, including age, gender and body mass index, were not completely unified. The LS incidence ranged from 6.0% to 85.5%.

Table 1.

Summary of the selected studies

Study	Subject	Age, years	Gender, M/F	Incidence of LS	LS-related factor
Akahane et al, 201721	Internet	58.7±16.7	374/373	108/747 (14.5%)	Gender
Chiba et al, 201622	Basic health check-up	58.4±11.0	247/400	39/647 (6.0%)	Age and body mass index
Hirano et al, 201323	Basic health check-up	67.6±8.7	131/233	62/364 (17.0%)	Age and gender
Iizuka et al, 201524	Basic health check-up	64.7±11.2	100/187	43/287 (15.0%)	Age
Ikemoto et al, 201625	Physical fitness centre	71.8±6.1	N/A	40/150 (26.7%)	Age, grip strength, back muscle strength, timed up-and-go and one-leg standing time
Imagama et al, 202026	Basic health check-up	64.3±10.1	427/589	146/1016 (14.4%)	Age, gender, lumbar lordosis angle, spinal inclination angle, grip strength, back muscle strength and timed up-and-go
Izawa et al, 201927	Rheumatoid arthritis	64.1±3.2	325/1385	828/1710 (48.4)	Gender
Machino et al, 202028	Basic health check-up	64.0±10.1	89/122	85/211 (40.3%)	Age and body mass index
Muramoto et al, 201329	Basic health check-up	68.8±6.8	167/239	65/406 (16.0%)	Age, gender, body mass index, grip strength, back muscle strength, maximum stride, timed up-and-go and one-leg standing time
Muramoto et al, 201430	Basic health check-up	68.2±5.0	0/217	36/217 (16.6%)	Age and body mass index
Muramoto et al, 201631	Basic health check-up	66.2±9.7	0/125	26/125 (20.8%)	Age, body mass index, lumbar lordosis, spinal inclination angle, back muscle strength, maximum stride, timed up-and-go and one-leg standing time
Nakamura et al, 201532	Basic health check-up	61.8±10.2	0/126	14/126 (11.1%)	Age, body mass index and one-leg standing time.
Nakamura et al, 201733	Basic health check-up	68.3±6.4	79/165	34/244 (13.9%)	Age, gender and depression
Nishimura et al, 201834	Basic health check-up	71.7±9.4	158/302	97/460 (21.1%)	Age, gender, one-leg standing time and normal gait speed
Saito et al, 201735	Outpatient clinic	77.8±5.9	41/159	99/200 (49.5%)	Age, gender and depression
Seichi et al, 201436	Outpatient clinic	77.0±6.0	261/619	497/880 (56.5%)	Age and one-leg standing time
Sobue et al, 202137	Rheumatoid arthritis	69.8±13.1	54/159	160/213 (75.1%)	Age
Tajika et al, 201738	Medical examinations	67.5±11.5	115/205	51/320 (15.9%)	Age and gender
Tanaka et al, 202045	Basic health check-up	71.0±6.2	42/126	37/168 (22.0%)	Age, gender and timed up-and-go
Tanaka et al, 201945	Basic health check-up	64.1±10.3	122/170	172/292 (58.9%)	Age, gender, body mass index, grip strength, back muscle strength and timed up-and-go
Tanaka et al, 201945	Basic health check-up	64.4±10.1	230/311	62/541 (11.5%)	Age, grip strength, back muscle strength and timed up-and-go
Tanaka et al, 201945	Basic health check-up	64.1±10.5	119/167	35/286 (12.2%)	N/A
Tanaka et al, 202045	Basic health check-up	64.1±10.1	196/281	60/477 (12.6%)	Age
Tanaka et al, 202045	Basic health check-up	64.7±9.9	252/353	70/605 (11.6%)	Age and body mass index
Tanaka et al, 202145	Basic health check-up	65.2±9.9	101/130	27/231 (11.7%)	N/A
Taniguchi et al, 202146	Mass communications	68.3±5.4	730/1347	251/2077 (12.1%)	Age, body mass index, osteoporosis, diabetes, grip strength, one-leg standing time and normal gait speed
Tsuji et al, 202147	Outpatient clinic	61.5±13.1	99/182	241/281 (85.5%)	Depression

Values are presented as the mean±SD.

F, female; LS, locomotive syndrome; M, male; N/A, non-available.

Quality assessment

The Newcastle-Ottawa Scale scores for the included studies were carefully assessed (table 2). The scores ranged from 4 (unsatisfactory) to 7 (good).

Table 2.

Quality assessment of the included studies using the Newcastle-Ottawa scale adapted for cross-sectional studies

Study	Study design	Selection	Comparability	Outcome	Score
Akahane et al, 201721	Cross-sectional	★★★★		★★	6 (Satisfactory)
Chiba et al, 201622	Cross-sectional	★★	★	★★	5 (Satisfactory)
Hirano et al, 201323	Cross-sectional	★★★		★★	5 (Satisfactory)
Iizuka et al, 201524	Cross-sectional	★★★	★★	★★	7 (Good)
Ikemoto et al, 201625	Cross-sectional	★★	★	★★	5 (Satisfactory)
Imagama et al, 202026	Cross-sectional	★★★★	★	★★	7 (Good)
Izawa et al, 201927	Cross-sectional	★★		★★	4 (Unsatisfactory)
Machino et al, 202028	Cross-sectional	★★★		★★	5 (Satisfactory)
Muramoto et al, 201329	Cross-sectional	★★	★	★★	5 (Satisfactory)
Muramoto et al, 201430	Cross-sectional	★★	★	★★	5 (Satisfactory)
Muramoto et al, 201631	Cross-sectional	★	★	★★	4 (Unsatisfactory)
Nakamura et al, 201532	Cross-sectional	★★	★★	★★	6 (Satisfactory)
Nakamura et al, 201733	Cross-sectional	★★★★		★★	6 (Satisfactory)
Nishimura et al, 201834	Cross-sectional	★★★	★★	★★	7 (Good)
Saito et al., 201735	Cross-sectional	★★★	★	★★	6 (Satisfactory)
Seichi et al, 201436	Cross-sectional	★★★		★★	5 (Satisfactory)
Sobue et al, 202137	Cross-sectional	★★★		★★	5 (Satisfactory)
Tajika et al, 201738	Cross-sectional	★★★	★★	★★	7 (Good)
Takenaka et al, 202039	Cross-sectional	★★	★★	★★	6 (Satisfactory)
Tanaka et al, 201940	Cross-sectional	★★★	★★	★★	7 (Good)
Tanaka et al, 201940	Cross-sectional	★★★	★★	★★	7 (Good)
Tanaka et al, 201940	Cross-sectional	★★		★★	4 (Unsatisfactory)
Takenaka et al, 202039	Cross-sectional	★★★	★★	★★	7 (Good)
Takenaka et al, 202039	Cross-sectional	★★★		★★	5 (Satisfactory)
Tanaka et al., 202145	Cross-sectional	★★		★★	4 (Unsatisfactory)
Taniguchi et al, 202146	Cross-sectional	★★★		★★	5 (Satisfactory)
Tsuji et al, 202147	Cross-sectional	★★	★	★★	5 (Satisfactory)

Selection (Maximum 5 stars): 1) Representativeness of the sample (a. Truly representative of the average in the target population [one star]; b. Somewhat representative of the average in the target group [one star]; c. The selected group of users/convenience sample [no star]; d. No description of the derivation of the included subjects [no star]); 2) Sample size (a. Justified and satisfactory [one star]; b. Not justified [no star]; c. No information provided [no star]): 3. Non-respondents (a. The proportion of target sample recruited attains pre-specified target or basic summary of non-respondent characteristics in sampling frame recorded [one star]; b. Unsatisfactory recruitment rate, no summary data on non-respondents [no star]; c. No information provided [no star]): 4) Ascertainment of the exposure (a. Hospital records only [two stars]; b. Parental or personal recall and hospital records [one star]; c. Parental/personal recall only [no star]). Comparability (Maximum 2 stars): 1) Confounding factors controlled (a. All relevant confounding factors controlled [two stars]; b. Some relevant confounding factors controlled [one star]; c. no relevant confounding factor controlled [no star]). Outcome (Maximum 3 stars): 1) Assessment of outcome (a. Independent blind assessment using objective validated laboratory methods [two stars]; b. Unblinded assessment using objective validated laboratory methods [two stars]; c. Used non-standard or non-validated laboratory methods with the gold standard [one star]; d. No description/non-standard laboratory methods used [no star]): 2) Statistical test (a. The statistical test used to analyze the data clearly described, appropriate and measures of the association presented including confidence intervals and probability level [one star]; b. Statistical test not appropriate, not described, or incomplete [no star]). Scores: 9–10 stars, very good studies; 7–8 stars, good studies; 5–6 stars, satisfactory studies; 0–4 stars, unsatisfactory studies.

Risk of publication bias

Online supplemental figures 2–6 show the funnel plots for clinical characteristics. All the values were within the range of acceptability and close to the no-effect line in funnel plots for the studies on skeletal muscle mass index, osteoporosis, diabetes, depression, lumbar lordosis angle, spinal inclination angle, maximum stride and normal gait speed. Moreover, funnel plots for the studies on age and grip strength were relatively symmetrical, showing that publication bias was not evident.

In contrast, some values were outside the range of acceptability and far from the no-effect line in funnel plots for the studies on gender and body mass index. Furthermore, funnel plots for the studies on back muscle strength, timed up-and-go and one-leg standing time were asymmetrical, showing that publication bias may exist.

Systematic review results

No heterogeneity was found in terms of gender (I²=46%, p=0.009), body mass index (I²=36%, p=0.05), skeletal muscle mass index (I²=18%, p=0.30), osteoporosis (I²=47%, p=0.15), diabetes (I²=37%, p=0.21), depression (I²=0%, p=0.57), lumbar lordosis angle (I²=0%, p=0.54), spinal inclination angle (I²=45%, p=0.18), maximum stride (I²=40%, p=0.19) and normal gait speed (I²=0%, p=1.00). Thus, a fixed model was used. Contrastingly, a significant heterogeneity was found in terms of age (I²=63%, p<0.00001), grip strength (I²=62%, p=0.01), back muscle strength (I²=93%, p<0.00001), timed up-and-go (I²=85%, p<0.00001) and one-leg standing time (I²=80%, p<0.0001). Therefore, a random model was used.

Older age (MD 4.71; 95% CI 3.97 to 5.44; p<0.00001), female gender (OR 1.54; 95% CI 1.38 to 1.71; p<0.00001), higher body mass index (MD 0.78; 95% CI 0.57 to 0.99; p<0.00001), osteoporosis (OR 1.68; 95% CI 1.32 to 2.13; p<0.0001), depression (OR 3.14; 95% CI 1.81 to 5.44; p<0.0001), lower lumbar lordosis angle (MD −7.91; 95% CI −10.08 to −5.74; p<0.00001), higher spinal inclination angle (MD 2.70; 95% CI 1.76 to 3.65; p<0.00001), lower grip strength (MD −4.04; 95% CI −5.25 to −2.83; p<0.00001), lower back muscle strength (MD −15.32; 95% CI −23.83 to −6.81; p=0.0004), lower maximum stride (MD −19.36; 95% CI −23.25 to −15.47; p<0.00001), higher timed up-and-go (MD 1.36; 95% CI 0.92 to 1.79; p<0.00001), lower one-leg standing time (MD −19.13; 95% CI −23.29 to −14.97; p<0.0001) and slower normal gait speed (MD −0.20; 95% CI −0.22 to −0.18; p<0.0001) were determined to be associated with LS (table 3 and online supplemental figures 7–10). No significant differences were found between the two groups in other clinical characteristics.

Table 3.

Systematic review results

Clinical characteristics	No of studies	Statistical heterogeneity		Effects model	Pooled OR or MD	95% CI	P value
		I2 (%)	P value
Age	25	63	<0.00001	Random	4.71	3.97 to 5.44	<0.00001
Female gender	22	46	0.009	Fixed	1.54	1.38 to 1.71	<0.00001
Body mass index	21	36	0.05	Fixed	0.78	0.57 to 0.99	<0.00001
Skeletal muscle mass index	4	18	0.30	Fixed	–0.08	–0.18 to 0.002	0.11
Osteoporosis	3	47	0.15	Fixed	1.68	1.32 to 2.13	<0.0001
Diabetes	2	37	0.21	Fixed	1.32	0.95 to 1.84	0.10
Depression	3	0	0.57	Fixed	3.14	1.81 to 5.44	<0.0001
Lumbar lordosis angle	2	0	0.54	Fixed	–0.79	–10.08 to 5.74	<0.00001
Spinal inclination angle	2	45	0.18	Fixed	2.70	1.76 to 3.65	<0.00001
Grip strength	7	62	0.01	Random	–4.04	–5.25 to 2.83	<0.00001
Back muscle strength	5	93	<0.00001	Random	–15.32	–23.83 to 6.81	0.0004
Maximum stride	2	40	0.19	Fixed	–19.36	–23.25 to 15.47	<0.00001
Timed up-and-go	7	85	<0.00001	Random	1.36	0.92 to 1.79	<0.00001
One-leg standing time	7	80	<0.0001	Random	–19.13	–23.29 to 14.97	<0.00001
Normal gait speed	2	0	1.00	Fixed	–0.20	–0.22 to 0.18	<0.00001

MD, mean difference.

Discussion

To the best of our knowledge, this review is the first to compile the currently available evidence on LS clinical characteristics that are categorised by the GLFS-25 questionnaire items. Our findings revealed that associations between older age, female gender, higher body mass index, presence of osteoporosis, presence of depression, lower lumbar lordosis angle, higher spinal inclination angle, lower grip strength, lower back muscle strength, lower maximum stride, higher timed up-and-go, lower one-leg standing time and slower normal gait speed with LS. Accordingly, GLFS-25 is clinically useful for assessing mobility function.

In this study, an association was found between older age, female gender, higher body mass index, osteoporosis and depression with LS. In addition, lumbar spine diseases and osteoarthritis (knee/hip) have been identified to be the main causes of LS, which are reported to be associated with older age, female gender, as well as osteoporosis and being overweight.5 24 46 47 From a research viewpoint, these clinical characteristics could be a confounding factor in the LS-related factors evaluation using the GLFS-25 and thus should be adjusted in future studies.

An association was found between depression and LS. Similar to our findings, past investigators revealed the relationship between the presence of depressive symptoms and a declined physical performance.^{33 35 47} Therefore, not only exercise therapy, such as locomotion training, but also psychological treatment for depressive states may be required in patients with LS.³⁵

Lower lumbar lordosis angle and higher spinal inclination angle were found to be associated with LS. Particularly, sagittal spinopelvic malalignment was associated with LS. Therefore, sagittal spinopelvic malalignment may be a trigger for suspected LS.⁴⁹ The spinal inclination angle was observed as the most relevant for LS among the sagittal spinopelvic parameters, and a spinal inclination angle of ≥6° has a sensitivity of 52% and specificity of 87% for LS category.³¹

Lower muscle strength (ie, lower grip strength and lower back muscle strength), mobility (ie, higher timed up-and-go and slower normal gait speed) and balancing (lower maximum stride and lower one-leg standing time) were associated with LS. These physical performance tests can help infer LS. Particularly, in terms of sensitivity and specificity for LS category, grip strength of ≤35 kg (males) and ≤23 kg (females) has 70% and 52%%–58%^{17 29 32}; back muscle strength of ≤78 kg (males) and ≤40 kg (females) has 59%–63% and 76%–80%²⁹; timed up-and-go of ≥6.7 s (males) and ≥7.5 s (females) has 73%–81% and 65%–83%²⁹; normal gait speed of ≤1.8 m/s (males) and ≤1.6 m/s (females) has 59%–72% and 70%–84%^{29 32}; maximum stride of ≤119 cm (males) and ≤104 cm (females) has 65%–71% and 57%–79%²⁹; and the one-leg standing time of ≤21 s (males) and ≤15 s in (females) has 69%–71% and 73%–74%.^{29 32 36}

Limitation

This systematic review has several limitations. First, a database (PubMed and Google Scholar) and English language bias may exist. However, a wide range of search terms (ie, “locomotive syndrome”) was set, and a lot of literature was screened. Second, a reporting bias may exist because some of the included studies21 26 27 34 43 reported financial conflicts of interest. Third, the quality of our results is dependent on the included studies. Particularly, the inclusion criteria, age, gender and body mass index were not completely unified, resulting in differences in terms of LS incidence. These partially reflected the Newcastle-Ottawa Scale assessment, which ranged from unsatisfactory to good quality. Accordingly, sensitivity analysis was conducted on studies deemed to be satisfactory, good and very good (online supplemental table 3). The results showed robustness although lumbar lordosis angle, spinal inclination angle and maximum stride were not applicable due to the number of studies. Fourth, a measurement bias may exist. Particularly, the number of times the physical test was performed and the process of selecting the value (mean, maximum and minimum) differed between the studies. Finally, and most importantly, all included studies in this systematic review were published in Japan. Therefore, the concept of LS and its management need to be disseminated and communicated not only in Japan but also in the world, and investigating whether the same result can be obtained in other ethnicities is necessary.

Conclusion

Currently available evidence on the clinical characteristics of LS categorised by the GLFS-25 questionnaire items was first compiled. Our findings revealed that LS was associated with older age, gender, higher body mass index, presence of osteoporosis and depression, lower lumbar lordosis angle, higher spinal inclination angle, lower grip strength, lower back muscle strength, lower maximum stride, higher timed up-and-go, lower one-leg standing time and slower gait speed. Accordingly, GLFS-25 is clinically useful for assessing mobility function.

The concept of LS and its management needs to be disseminated and communicated not only in Japan but also in the world, and investigating whether the same result can be obtained in other ethnicities is necessary.

Data availability statement

Data are available in a public, open access repository. All the data relevant to the study are included in the article or uploaded as online supplemental information.

Ethics statements

Patient consent for publication

Not applicable.

Ethics approval

Ethics committee or institutional review board approval was not required because this was a systematic review. The review protocol was not prepared.