Indonesia is an aging society. According to Indonesian Central Bureau of Statistics (BPS) data in 2020, the number of citizens aged 60 years or older in Indonesia reached 26.82 million, or approximately 9.92% of the total population. This number is predicted to increase to around 20% in 2045.¹⁾ Aging causes the deterioration of various organs, including locomotor organs such as the bones, joints, muscles, and nerves.²⁾ Locomotive syndrome (LS) is a state of degraded mobility due to impaired locomotive organs, which results in an increased risk of disability.³⁾ This syndrome, characterized by decreased physical function in older adults, leads to limitations 1st in activities of daily living (ADL) and reduced quality of life.^2,3) Locomotion syndrome is classified into three stages depending on the severity of locomotion dysfunction. Locomotion stage 1 indicates the beginning of the mobility function decline and is recommended to perform exercise training (locomotion training). Locomotion stages 2 and 3 need further physician evaluation before any intervention is taken.^2,3)

The decrease in physical function with increasing age can be assessed by measuring exercise capacity using maximal and submaximal exercise tests to measure maximum oxygen consumption (VO_2max).⁴⁾ The 2-minute walk test (2MWT) is a shorter and relatively safer submaximal training test, especially for frail older adults. These tests are safe and simple, provide the same information on mobility, and are valid and reliable for the measurement of aerobic capacity in older adults.^5,6)

Physical exercise can improve physical function, reduce inflammation, and delay dependence in older adults.^7-9) The recommended physical exercise program for older adults is multicomponent exercises that include strength, flexibility, balance, and aerobic exercise.¹⁰⁾ The locomotion training developed by the Japanese Orthopedic Association is a combination of strengthening and balance exercises that are proven safe, simple, and effective for improving the physical function of older adults.^2,3)

Nursing homes in Indonesia are funded mainly by the government, private companies, and charity organizations. Usually, only older adults with comorbidities and poor financial support move to nursing homes.¹¹⁾ Due to the lack of funds and staff, many of these nursing homes cannot provide comprehensive and multimodal exercise programs to their residents. Thus, short-duration, low-to-moderate-intensity aerobic exercise has become a staple in most nursing homes in Indonesia.

The present study aimed to assess the effect of locomotion training and regular aerobic exercise programs on the aerobic capacity of older adults with LS stage 1 living in nursing homes. We hypothesized that older adults who participated in the intervention groups would show significantly improved outcomes compared to their peers in the control group (CG).

The mean ages of the LTG and CG (75.40±4.88 and 72.30±4.30 years, respectively) were similar, and most participants in both the groups were female (70% in both the groups). The other demographic characteristics of the two groups were also similar (Table 1). We observed no significant differences in the mean and SD of baseline body weight, height, BMI, GLFS-25, 2MWT, and VO_2max between the LTG and CG (Table 1). Two participants each in the LTG and CG dropped out of the study. Hence, the study was completed by 10 participants each in the LTG and CG. The outcomes of within- and between-group assessments after calculating the median and mean values for each scale before and after the 8-week intervention were also performed. The mean 2MWT score before and after the 8-week intervention differed significantly in the LTG (p=0.001). The mean and SD of 2MWT before the intervention, 91.70±20.90, increased to 107.00±21.38 after the intervention, indicating the effectiveness of the additional locomotion training on improving mobility in older adults with LS. However, we observed no significant changes in the CG (p=0.249). The mean 2MWT values differed significantly between the two groups after the 8-week intervention (p=0.004) (Table 2). The mean VO_2max differed significantly before and after the 8-week intervention in the LTG and CG (p<0.001 and p=0.022, respectively). The mean and standard deviation of VO_2max before the intervention, 28.9±6.9, increased to 33.4±8.3 after the intervention in the LTG. Moreover, the mean and SD of the VO_2max before the intervention, 34.6±8.6, increased to 36.6±8.8 after the intervention. The two groups also showed a significant difference in the mean VO_2max values after the 8-week intervention (p=0.016) (Table 3).

The present study assessed the effect of locomotion training and regular aerobic exercise programs on older adults with LS stage 1 who were nursing home residents. LS is a condition of reduced mobility due to impairment of the locomotive organs. Because upright bipedal walking involves minutely controlled movement patterns, it can be adversely affected by the impairment of any aspect of the locomotive organs. The progression of these impairments eventually results in limitations in ADL, reduction in quality of life, and the necessity for care support. Based on the 2020 LS criteria, LS can be classified into three stages based on the total GLFS-25 score, with scores ≥7 to <16, ≥16 to <24, and ≤24 categorized as LS stages 1, 2, and 3, respectively. A higher score indicates lower locomotive function, and physical performance test results differ significantly between LS stages 2 and 3, while muscle strength differs significantly between LS stages 1 and 2.^2,3,13)

Functional mobility and independence are the main objectives of rehabilitation programs. Functional capacity reflects an individual’s aerobic capacity.⁶⁾ The current concept of LS focuses on strength and balance impairments in determining decreased functional capacity and mobility in older adults.^2,3) The lower limb muscle strength is strongly positively correlated with body balance in older adults.¹⁷⁾ Strength and balance are often significant contributors to mobility limitations, and aerobic capacity, often measured as maximal oxygen uptake (VO_2max) or peak oxygen uptake (VO_2peak), also correlates with self-reported difficulty and disability and timed functional performance in older adults.¹⁸⁾

Aerobic capacity is generally assessed by measuring VO_2max. However, this measurement requires complex equipment and laboratories, specific and expensive equipment, supervision of a professional medical team, and consideration of the motivation and physical effort of the subject to undergo the training test. Therefore, an alternative test is required to estimate VO_2max using a submaximal training test.^6,19)

The 6MWT is a standardized test developed by the American Thoracic Society in 2002 to measure VO_2max. However, this test has limitations in older adults, especially those with frailty. The 6MWT is too tiring, takes longer, and increases the risk of falling in frail older adults; therefore, the 2MWT may be an alternative in this population. The 2MWT has good validity, as anthropometric parameters of weight, height, age, sex, and walking speed in the 2MWT were significantly correlated with VO_2max during the 6MWT submaximal training test. The 2MWT also has excellent test-retest reliability in frail older adults.⁶⁾

In older adults, physical activity is associated with many health benefits and functional abilities, including ADL mobility and independence. Physical activity also promotes better outcomes in older adults with chronic diseases. Physical exercise reduces the risk of falls and improves physical function, particularly in frail older adults with limited mobility.^7,20)

In this study, locomotion training and a regular aerobic exercise program for 8 weeks resulted in a significant increase in 2MWT in the LTG (15.3±9.8 m). In contrast, we observed no significant change between the baseline and post-exercise periods in the CG. Connelly et al.⁵⁾ reported that the minimum change value for the 2MWT to show the effect of exercise on the aerobic capacity of older adults in nursing homes was 15 m, with a time between measurements of at least 1 week.

The walking test for measuring aerobic capacity indicates the capacity for independent mobility, defined as the ability to adjust body position independently, strength for vertical and horizontal transitions, and aerobic fitness. Tests based on runs have limitations for use in older individuals with multisystem disorders.⁵⁾ Walking test results are also highly correlated with other mobility measures, including balance and strength.²¹⁾ LS is characterized by decreased balance and strength. Locomotion training combines strengthening and balance exercises; therefore, regular locomotion training can improve these factors, including the mobility ability of patients with LS.^2,3) This improved mobility capability is evident in the 2MWT results.

Comparisons of mean VO_2max values before and after the 8-week intervention showed a significant difference between the LTG and CG (p = 0.016). Both the groups showed significantly increased VO_2max; however, the difference was greater in the LTG than in the CG. A meta-analysis by Hurst et al.²²⁾ concluded that for the same duration, a combination of aerobic and strengthening exercises provided a better benefit in increasing VO_2max compared to aerobic exercise alone in a population aged >50 years. This is because aging simultaneously affects several physiological systems. Therefore, physical exercise in older adults should include resistance training, aerobics, balance, and flexibility exercises.²³⁾

This study had several limitations. First, this study was performed during the coronavirus disease 2019 pandemic and included a relatively small number of participants in a single study area. Owing to the small number of participants, we could not assess the effect of locomotion training addition based on participant sex; therefore, sex differences in locomotive performance could be possible. Moreover, most participants were women; therefore, the results could not completely reflect the older population. Follow-up studies with larger sample sizes and geographical areas are warranted. Second, long-term effects of locomotion training were not monitored and the total exercise duration was longer in the LTG than in the CG. These differences in exercise durations also affected the results of the locomotion training. The evaluation of the long-term effects and an increased duration of the CG is recommended in follow-up studies.

In conclusion, the addition of locomotion training to a regular aerobic exercise program in nursing homes showed positive effects on improving mobility and aerobic capacity in older adults with LS stage 1. Locomotive training may be an effective intervention to prevent and slow LS progression in older adults living in nursing homes.