Predictive Ability of the 2-Minute Step Test for Functional Fitness in Older Individuals with Hypertension

Puttipong Poncumhak; Patchareeya Amput; Noppharath Sangkarit; Tichanon Promsrisuk; Arunrat Srithawong

doi:10.4235/agmr.23.0070

Ann Geriatr Med Res > Volume 27(3); 2023 > Article

Poncumhak, Amput, Sangkarit, Promsrisuk, and Srithawong: Predictive Ability of the 2-Minute Step Test for Functional Fitness in Older Individuals with Hypertension

Original Article

Annals of Geriatric Medicine and Research 2023;27(3):228-234.

Published online: July 28, 2023

DOI: https://doi.org/10.4235/agmr.23.0070

Predictive Ability of the 2-Minute Step Test for Functional Fitness in Older Individuals with Hypertension

Puttipong Poncumhak^1,², Patchareeya Amput^1,², Noppharath Sangkarit^1,², Tichanon Promsrisuk³, Arunrat Srithawong^1,²

¹Department of Physical Therapy, School of Allied Health Sciences, University of Phayao, Phayao, Thailand

²Unit of Excellence of Human Performance and Rehabilitations, University of Phayao, Phayao, Thailand

³Division of Physiology, School of Medical Sciences, University of Phayao, Phayao, Thailand

Corresponding Author: Arunrat Srithawong, MSc Department of Physical Therapy, School of Allied Health Sciences, University of Phayao, 19 Moo 2 Tambon Maeka, Amphur Muang, Phayao 56000, Thailand
E-mail: Arunrat.sr@up.ac.th

Received May 16, 2023 Revised June 29, 2023 Accepted July 21, 2023

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

The 2-minute step test (2MST) is a simple and inexpensive functional test that measures an individual's ability to perform continuous stepping up and down on a step platform for two minutes. This study evaluated the 2MST as a tool for assessing functional fitness in older individuals with hypertension and determined the correlation between the 2MST and physical fitness tests.

Methods

A total of 91 older individuals with hypertension performed physical fitness tests, including the 2MST, 6-minute walk test (6MWT), five times sit-to-stand test (FTSST), grip strength and leg strength assessments, and timed up and go test (TUG) to collectively assess their physical fitness.

Results

A cutoff score of ≤60 steps in the 2MST had 87.50% sensitivity and 70.59% specificity in predicting functional exercise performance in older individuals with hypertension. Additionally, the number of steps in the 2MST was positively correlated with the distance covered in the 6MWT, isometric grip strength, and isometric leg strength and negatively correlated with the duration of the FTSST and TUG.

Conclusions

A cutoff score of ≤60 steps in the 2MST predicted functional exercise performance in older individuals with hypertension with 87.50% sensitivity and 70.59% specificity and was correlated with other physical fitness tests, suggesting that the 2MST is a useful tool for assessing functional exercise performance.

Key words: Hypertension, Aging, Step test, Physical fitness testing

INTRODUCTION

The world's aging population is increasing, and the elderly population is projected to constitute approximately 30% of the global population by 2050.¹⁾ Aging is a significant risk factor for chronic diseases and can trigger the onset of geriatric syndromes and illnesses owing to changes in physiological systems.^2-⁴⁾ Hypertension is a prevalent condition in older adults, affecting >70% of the population. This condition is associated with increased risks of cardiovascular disease, cognitive decline, and physical disability.⁵⁾ Moreover, sarcopenia is characterized by the age-related loss of muscle mass and strength; hypertension can exacerbate this process, leading to further deterioration in physical capabilities.^6,⁷⁾

Functional fitness, which is the ability to perform daily tasks safely and independently without exhaustion or discomfort, is a critical component of healthy aging. It enables individuals to maintain their independence and quality of life.⁸⁾ The increase in the number of functionally limited individuals with hypertension highlights the need for early detection and interventions to alleviate the burden of hypertension-aging-disability.⁵⁾ Therefore, the accurate identification of functional impairment can assist in tailoring interventions to improve fitness, set achievable goals, and educate individuals about the importance of physical fitness for daily tasks and overall health.

Aerobic capacity, a key aspect of physical fitness, is commonly assessed in healthy and diseased populations.⁹⁾ The 6-minute walk test (6MWT) is a common method used to evaluate the submaximal functional aerobic capacity in older adults^9-¹¹⁾ but its administration requires a 30-m hallway and can be time-consuming for routine outpatient consultations. Simple and quick office-based field exercise tests, such as the 2-minute step test (2MST)^12,¹³⁾ may be valuable options as first screening tools before a detailed assessment of functional status and subsequent treatment. The 2MST is highly correlated with the 6MWT^14-¹⁶⁾ indicating its potential as a measure of functional aerobic capacity. Its correlation with the timed up and go test (TUG),¹⁶⁾ five times sit-to-stand test (FTSST), and leg strength¹⁵⁾ highlights the close relationship between cardiovascular endurance, muscle strength, and functional mobility.¹⁷⁾

Evaluating functional fitness using the available tools can be difficult because of variations in body composition, physical capacity, and perceptions of physical functioning among different populations and research settings.^12,¹⁸⁾ The assessment of functional capacity is particularly critical in estimating the functional consequences and disability among patients with hypertension. Owing to the limitations of studies evaluating the tests to assess the functional capacity evaluation test specifically in individuals with hypertension, the present study investigated the predictive ability of the 2MST to identify functional impairment in hypertensive older adults and its correlation with other functional measures, including the 6MWT, FTSST, TUG, grip strength, and leg strength.

MATERIALS AND METHODS

1. Participants

This cross-sectional study included on 91 older individuals with hypertension in Phayao Province, Thailand, who were undergoing routine antihypertensive medication therapy. We identified and recruited eligible participants during their routine appointments at a primary healthcare center, and informed consent was obtained from all individuals before their participation. The study included participants who met specific criteria, including a diagnosis of hypertension, age >60 years, body mass index (BMI) <30 kg/m², and absence of any physical limitations that would impact their ability to walk or perform stepping movements. Participants with respiratory diseases or clinical conditions such as cognitive impairment, uncontrolled hypertension, unstable angina, and infectious diseases were excluded from the study. This study was approved by the Human Research Ethics Committee of the University of Phayao (No. 1.2/056/65). The minimum estimated sample size required was 62 participants for a diagnostic study, with a 90% power, 0.05 p-value, and 80% sensitivity based on a previous study.¹⁹⁾

This study complied the ethical guidelines for authorship and publishing in the Annals of Geriatric Medicine and Research.²⁰⁾

2. Procedure

The experimental protocol was divided into two visits. On the first visit, we assessed the participants’ general information using a self-reported questionnaire, and collected socio-demographic (age and sex), anthropometric (height and weight to compute BMI), and general clinical data (duration of hypertension, medical conditions, and physical activity) using the Physical Activity Questionnaire for Elderly Japanese.²¹⁾ Subsequently, a physical fitness test, handgrip strength measurement, leg strength measurement, TUG, FTSST, and 2MST were performed for each participant with a 30-minute rest between tests. During the second visit on the following week, the participants performed the 6MWT.

Hand grip strength was measured with a Jamar Hand Dynamometer (Sammons Preston, Bolingbrook, IL, USA). After a practice test, participants were instructed to stand with their arms extended, and squeeze the dynamometer twice as hard as possible for 3 seconds with the dominant arm. The participants were allowed to rest between measurements. Three trials were performed and the average values were recorded, regardless of hand dominance.²²⁾

In the 6MWT protocol, the participants were asked to sit on a chair for 5 minutes to record their vital signs, dyspnea, and leg fatigue. They were then instructed to walk as fast as possible for 6 minutes without running and to continue at the same pace without stopping. The distance covered by each participant was recorded.⁹⁾ One minute after the test, the participants’ vital signs, dyspnea, and leg fatigue were recorded.

In the 2MST protocol, the participants were instructed to stand against a wall, and marks were made on the wall at the level of the anterior superior iliac crest and patella. Half of the distance between the two marks was marked using a piece of tape. The participants were asked to lift their knees to the height marked by the tape while treading in place as quickly as possible for 2 minutes. The number of steps taken on the right side to reach the criterion height was counted for each participant and recorded.²³⁾

In the FTSST protocol, the participants were asked to stand up and sit down as fast as possible five times with their arms folded across their chests. Two trials were conducted with a rest period of 1 minute between trials. The average time of two trials was recorded as the test result.²⁴⁾

In the leg strength protocol, the participants were instructed to stand with their feet shoulder-width apart on the dynamometer base and hold onto a bar with their hands. The chain was adjusted such that the knees were flexed at 110°. The participants were then asked to pull as hard as possible on the chain while trying to straighten their legs and keep their upper limbs straight without flexing their backs. Each subject performed two trials and the maximum performance was recorded.²⁵⁾

The TUG protocol involved measuring the time required for the participants to rise from a chair with an approximate seat height of 46 cm, walk 3 m to a line on the floor, turn, walk back to the chair, and sit down again. The participants had one practice walk-through before being timed for three attempts with 1-minute rest intervals and verbal encouragement. The shortest time was recorded for analysis.^26-²⁸⁾

3. Statistical Analysis

We computed the descriptive statistics, including means, standard deviations, and percentages, for the participant characteristics and study outcomes. Receiver operating characteristic (ROC) curve analysis was used to identify the accuracy of the 2MST in differentiating older adults with hypertension with and without functional impairment. We used a 6MWT cut-off of 320 m,¹⁴⁾ which is associated with low exercise endurance in older adults. Based on these cutoffs, we identified the threshold for the 2MST to identify functional impairments. The area under the curve (AUC), best cut-off point, sensitivity, and specificity were identified. We compared older adults with hypertension below or above the cut-off point in the 2MST using the independent samples t-test or Mann–Whitney U test, as appropriate. Physiological responses—blood pressure (BP), heart rate (HR), and oxygen saturation (O₂ sat)—and differences between the 2MST and 6MWT were evaluated using dependent samples t-test or signed-rank test. Leg fatigue and dyspnea scores were measured using the signed-rank test. Pearson correlation coefficient was used to verify the correlation between the 2MST and 6MWT, handgrip strength, leg strength, TUG, FTSST, and 6MWT. Data were analyzed using Stata 14.0 (StataCorp LLC, College Station, TX, USA), with a significance level of 5%.

RESULTS

This study enrolled 91 older individuals with hypertension, with a mean age of 70.29±4.95 years and an almost equal distribution of men (49.45%) and women (50.55%). The participants had a mean body weight of 58.59±0.71 kg, a mean height of 160.94±12.02 cm, and a mean BMI of 22.59±3.85 kg/m². The average duration of hypertension since diagnosis was 8.87±3.54 years, and most participants had comorbidities including diabetes (48.4%), dyslipidemia (38.46%), and orthopedic problems (9.89%). A small proportion of participants had cardiovascular disease (8.79%). The participants' level of physical activity was 8.77±5.23 metabolic equivalents (METs) hr/wk, indicating moderate physical activity levels. Table 1 summarizes the participants’ characteristics.

As shown in Table 2, the 2MST had an optimal cut-off score of ≤60 steps, with a sensitivity of 87.50% and a specificity of 70.59%. The AUC was 0.91 (95% confidence interval, 0.84–0.97).

Compared to the group of participants that completed the 2MST with ≥60 steps, those that completed the test with <60 steps had significantly lower handgrip strength, leg strength, TUG, FTSST, and 6MWT distances (p<0.001), as well as significantly lower systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p<0.001 and p=0.036, respectively). The HR, HR as a percentage of the predicted maximum, O₂ sat, and dyspnea grade did not differ significantly between the groups (Table 3).

Table 4 shows the results of the comparison of physiological responses, dyspnea, and leg fatigue between the 2MST and 6MWT in older adults with hypertension. The HR in beats per minute (bpm) during the 2MST was significantly increased when compared to the 6MWT (86.91±14.10 bpm vs. 83.02±15.36 bpm; p<0.001), as well as the HR in percentage of predicted maximum HR (57.10%±2.56% vs. 54.69%±2.20%; p<0.001). SBP during the 2MST was also significantly higher than that during the 6MWT (154.33±21.61 mmHg vs. 144.42±18.71 mmHg; p<0.001). The DBP and O₂ sat levels did not differ significantly between the two tests (p=0.452 and p=0.050, respectively).

Regarding the subjective responses, the dyspnea and leg fatigue levels were significantly higher during the 2MST than those during the 6MWT (11.48±2.73 vs. 10.54±2.92, p=0.004 and 2.12±1.67 vs. 1.45±1.33, p<0.001, respectively). These results suggested that the 2MST may be more challenging in terms of cardiovascular and subjective responses than the 6MWT in older adults with hypertension (Table 4).

Table 5 presents the associations between the number of steps taken in the 2MST and various demographic and physical factors in older adults with hypertension. The results demonstrated a negative correlation between 2MST and age (r=-0.294, p=0.005), a positive correlation with height (r=0.332, p=0.001), and no significant correlation with body weight (r=0.144, p=0.172).

The results of several physical fitness tests in the same population, including the 6MWT distance, grip strength, leg strength, TUG duration, and FTSST duration showed that the number of steps in the 2MST was positively associated with the distance of the 6MWT (r=0.747, p<0.0001), isometric grip strength (r=0.567, p<0.0001), and isometric leg strength (r=0.472, p<0.0001). In contrast, the number of steps in the 2MST was negatively associated with FTSST (r=-0.491, p<0.0001) and TUG (r=-0.632, p<0.0001) duration (Table 5).

DISCUSSION

This study investigated the usefulness of the 2MST for assessing functional fitness in older individuals with hypertension and its correlation with other physical fitness tests. The results showed that the 2MST was effective in identifying functional limitations in this population, with a cutoff score of ≤60 steps indicating lower functional ability and physiological responses. Furthermore, the 2MST was more challenging than the 6MWT and was significantly correlated with demographic factors, handgrip strength, leg strength, TUG, and FTSST.

The 2MST was originally developed as a component of the Senior Fitness Test (SFT) by Rikli and Jones in 1999.¹⁶⁾ The SFT is a comprehensive set of tests designed to evaluate physical fitness in older adults, with the 2MST specifically assessing aerobic endurance and lower body strength.²⁹⁾ Various studies have demonstrated the 2MST's usefulness in assessing functional capacity and found it to be a reliable and valid measure of physical fitness in older adults.³⁰⁾ Our study found that a cutoff of 60 steps in the 2MST accurately distinguished older individuals with hypertension with or without functional impairment. This result is consistent with those of a previous study that identified the 2MST as the best predictor of functional capacity in hypertensive individuals, with an average of 69 repetitions and an AUC of 0.7.¹⁹⁾ Individuals who performed <60 repetitions in the 2MST exhibited longer times on the TUG and FTSST, indicating potential mobility and balance issues. These findings, along with lower handgrip and leg strength and higher leg fatigue, may suggest a decrease in overall physical fitness, including reduced endurance and physical capacity. Therefore, <60 repetitions in the 2MST may serve as a useful marker for identifying functional impairment, indicating the need for interventions to improve physical fitness and functional capacity in individuals with hypertension.

The 2MST is a good measure of cardiorespiratory fitness when other submaximal fitness tests cannot be undertaken, such as the 6MWT, and involves lifting the knees to the mid-level between the patella and iliac crest⁸⁾; thus, it requires more intensity and a longer duration of single-leg support than the standard step.³¹⁾ In our study of older adults with hypertension, the 2MST elicited a higher HR, SBP, dyspnea, and leg fatigue compared to the 6MWT. The biomechanics of the 2MST require greater lower-body strength, physical skills, and longer periods of single-leg support,^32,³³⁾ which explained the higher physiological demand and RPE compared with the 6MWT. The RPE was significantly higher in the 2MST group than in the 6MWT group.

The 2MST and 6MWT exhibit a strong correlation, indicating that both tests are reliable measures of cardiorespiratory fitness.³⁴⁾ Our results are consistent with those of previous studies, which suggests that the 2MST can complement the 6MWT in various populations, including those with coronary artery disease,³⁵⁾ hypertension in older adults,¹⁶⁾ symptomatic peripheral artery disease,³⁴⁾ and systolic heart failure.³⁶⁾ Additionally, other studies have reported an association between these tests in both healthy older individuals⁸⁾ and those with pathologies^16,³⁶⁾ suggesting that the 2MST can assess the integrated global response to exercise of all human body systems. We observed correlations between age, height, weight, and 2MST, suggesting that these factors may impact test performance and should be considered.

Our study results revealed significant inverse correlations between the 2MST and two functional mobility tests, the FTSST and TUG, which assess the ability to complete tasks such as standing up from a chair or standing on one leg. These results reinforce the strong relationship between cardiovascular endurance and functional mobility. A negative correlation implies that poor cardiovascular endurance may lead to poor functional mobility, and vice versa. These results are consistent with those of previous studies reporting a correlation between functional capacity and functional mobility in older adults with hypertension.^16,¹⁷⁾ Moreover, we observed a significant positive correlation between 2MST, handgrip strength, and leg strength. This supports prior research indicating a relationship between the 2MST and quadriceps strength in patients with systolic heart failure.³⁶⁾ In older adults, maintaining strong handgrip and leg muscles is crucial not only for completing daily tasks but also for reducing the risks of mortality, functional decline, disability, and falls.^37-³⁹⁾ Moreover, poor aerobic endurance and leg strength contribute significantly to slow gait velocity in community-dwelling patients with stroke.⁴⁰⁾

In conclusion, the 2MST is a useful tool for assessing functional capacity in older individuals with hypertension, with a cut-off of 60 steps accurately identifying functional impairment. The 2MST was positively correlated with the 6MWT, grip strength, and leg strength and negatively associated with the FTSST and TUG duration.

ACKNOWLEDGEMENTS

The authors thank all the men and women who participated in this study.

ACKNOWLEDGMENTS

CONFLICT OF INTEREST

The researcher claims no conflicts of interest.

FUNDING

This research was supported by Thailand Science Research and Innovation funds and the University of Phayao (Grant No. FF-RIM084 and FF66-UoE009).

AUTHOR CONTRIBUTIONS

Conceptualization, AS; Data curation, AS, PP; Funding acquisition, AS; Investigation, AS, TP, NS; Methodology, AS, TP, NS; Writing-original draft, AS, PA; Writing-review and editing, AS, PA, PP.

Table 1.

Characteristics of hypertensive older adults (n=91)

Variable	Hypertensive older adults
Age (y)	70.29±4.95
Sex
Male	45 (49.45)
Female	46 (50.55)
Body weight (kg)	58.59±0.71
Height (cm)	160.94±12.02
BMI (kg/m²)	22.59±3.85
PAQ-EJ score (METs, hr/wk)	8.77±5.23
SBP (mmHg)	135.91±16.55
DBP (mmHg)	73.31±9.20
Duration of hypertension (y)	8.87±3.54
Comorbidities
None	8 (8.79)
Diabetes	44 (48.4)
Dyslipidemia	35 (38.46)
Orthopedic problems (gout, rheumatoid disease)	9 (9.89)
Cardiovascular disease	8 (8.79)

Values are presented as mean±standard deviation or number (%).

BMI, body mass index; PAQ-EJ, Physical Activity Questionnaire for Elderly Japanese; METs, metabolic equivalents; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Table 2.

Optimal cut-off score, sensitivity, specificity, and AUC of the 2MST in all participants

Number of participants	Cut-off (steps)	Sensitivity (%)	Specificity (%)	AUC (95% CI)
91	≤60	87.50	70.59	0.91 (0.84–0.97)

2MST, 2-minute step test; AUC, area under the curve; CI, confidence interval.

Table 3.

Comparing physiological responses, dyspnea, leg fatigue, and functional ability in individuals below (n=31) or above (n=60) the 2MST cut-off point

Variable	Total (n=91)	2MST		p-value
Variable	Total (n=91)	<60 steps (n=31)	≥60 steps (n=60)	p-value
HR (beats/min)	85.26±6.36	83.58±10.20	88.63±15.53	0.080
HR (%pred)	57.10±2.56	56.21±6.74	58.61±10.69	0.182
SBP (mmHg)	153.16±28.28	143.61±18.62	159.87±21.09	<0.001^*
DBP (mmHg)	78.03±1.41	76.13±10.22	81.13±10.79	0.036^*
O₂ sat (%)	97.26±0.00	97.65±1.11	97.82±1.23	0.357
Dyspnea (6–20 grade)	9.77±0.00	11.26±2.71	11.60±2.76	0.595
Leg fatigue (0–10 grade)	1.47±3.54	2.58±1.54	1.88±1.69	0.040^*
2MST (step)	62.47±14.68	47.23±11.94	70.35±8.43	<0.001^*
Handgrip strength (kg)	23.15±7.04	18.21±4.60	25.70±6.74	<0.001^*
Leg strength (kg)	50.04±24.65	34.84±12.89	57.90±25.65	<0.001^*
TUGT (s)	11.71±3.88	14.25±5.12	10.40±2.14	<0.001^*
FTSST (s)	12.21±3.57	14.07±4.12	11.25±2.83	<0.001^*
6MWT (m)	334.56±83.11	266.68±77.81	369.62±61.53	<0.001^*

Values are presented as mean±standard deviation.

HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; O₂ sat, oxygen saturation; 2MST, 2-minute step test; TUG, timed up and go test; FTSST, five time sit-to-stand test; 6MWT, 6-minute walk test.

^* p<0.05, statistically significant.

Table 4.

A comparison of physiological responses, dyspnea, and leg fatigue between 6MWT and 2MST in hypertensive older adults (n=91)

Variable	2MST	6MWT	p-value
HR (beats/min)	86.91±14.10	83.02±15.36	<0.001^*
HR (%pred)	57.10±2.56	54.69±2.20	<0.001^*
SBP (mmHg)	154.33±21.61	144.42±18.71	<0.001^*
DBP (mmHg)	79.43±10.81	78.58±11.34	0.452
O₂ sat (%)	97.76±1.19	97.46±1.30	0.050
Dyspnea (6–20 grade)	11.48±2.73	10.54±2.92	0.004^*
Leg fatigue (0–10 grade)	2.12±1.67	1.45±1.33	<0.001^*

Values are presented as mean±standard deviation.

6MWT, 6-minute walk test; 2MST, 2-minute step test; HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; O₂ sat, oxygen saturation.

^* p<0.05, statistically significant.

Table 5.

Relationships between the 2MST and demographic factors, handgrip strength, leg strength, TUG, and FTSST in hypertensive older adults

Variable	2MST
Variable	r	p-valve
Age	-0.294	0.005^*
Height	0.332	0.001^*
Weight	0.144	0.172
6MWT	0.747	<0.001^*
Handgrip strength	0.567	<0.001^*
Leg strength	0.472	<0.001^*
FTSST	-0.491	<0.001^*
TUG	-0.632	<0.001^*

2MST, 2-minute step test; 6MWT, 6-minute walk test; FTSST, five times sit to stand test; TUG, timed up and go test.

^* p<0.05, statistically significant.

REFERENCES

1. United Nations. World population prospects: the 2015 revision. New York, NY: United Nations, Department of Economic and Social Affairs; 2015.

2. Boss GR, Seegmiller JE. Age-related physiological changes and their clinical significance. West J Med 1981;135:434–40.

3. Guo J, Huang X, Dou L, Yan M, Shen T, Tang W, et al. Aging and aging-related diseases: from molecular mechanisms to interventions and treatments. Signal Transduct Target Ther 2022;7:391.

4. Buford TW. Hypertension and aging. Ageing Res Rev 2016;26:96–111.

5. Mitchell WK, Williams J, Atherton P, Larvin M, Lund J, Narici M. Sarcopenia, dynapenia, and the impact of advancing age on human skeletal muscle size and strength: a quantitative review. Front Physiol 2012;3:260.

6. Kara M, Kara O, Ceran Y, Kaymak B, Kaya TC, Citir BN, et al. SARcopenia Assessment in Hypertension: The SARAH Study. Am J Phys Med Rehabil 2023;102:130–6.

7. Rikli RE, Jones CJ. Senior fitness test manual. 2nd ed. Champaign, IL: Human Kinetics; 2013.

8. Lim JY. Aging with disability: what should we pay attention to? Ann Geriatr Med Res 2022;26:61–2.

9. Thaweewannakij T, Wilaichit S, Chuchot R, Yuenyong Y, Saengsuwan J, Siritaratiwat W, et al. Reference values of physical performance in Thai elderly people who are functioning well and dwelling in the community. Phys Ther 2013;93:1312–20.

10. Bohannon RW. Hand-grip dynamometry predicts future outcomes in aging adults. J Geriatr Phys Ther 2008;31:3–10.

11. Galhardas L, Raimundo A, Del Pozo-Cruz J, Marmeleira J. Physical and motor fitness tests for older adults living in nursing homes: a systematic review. Int J Environ Res Public Health 2022;19:5058.

12. Amput P, Wongphon S, Srithawong A, Konsanit S, Naravejsakul K. The correlation among 2-minute step test, time up and go test, and sit to stand test in Phayao hypertensive older adults. J Med Assoc Thail 2021;104:1706–10.

13. Pedrosa R, Holanda G. Correlation between the walk, 2-minute step and TUG tests among hypertensive older women. Braz J Phys Ther 2009;13:252–6.

14. ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med 2002;166:111–7.

15. Enright PL, McBurnie MA, Bittner V, Tracy RP, McNamara R, Arnold A, et al. The 6-min walk test: a quick measure of functional status in elderly adults. Chest 2003;123:387–98.

16. Rikli RE, Jones CJ. Development and validation of a functional fitness test for community-residing older adults. J Aging Phys Act 1999;7:129–61.

17. Bohannon RW, Crouch RH. Two-minute step test of exercise capacity: systematic review of procedures, performance, and clinimetric properties. J Geriatr Phys Ther 2019;42:105–12.

18. Jones CJ, Rikli RE. Measuring functional. J Act Aging 2002;1:24–30.

19. Srithawong A, Poncumhak P, Manoy P, Kumfu S, Promsrisuk T, Prasertsri P, et al. The optimal cutoff score of the 2-min step test and its association with physical fitness in type 2 diabetes mellitus. J Exerc Rehabil 2022;18:214–21.

20. Noh JH, Jung HW, Ga H, Lim JY. Ethical guidelines for publishing in the Annals of Geriatric Medicine and Research. Ann Geriatr Med Res 2022;26:1–3.

21. Rikli RE, Jones CJ. Development and validation of criterion-referenced clinically relevant fitness standards for maintaining physical independence in later years. Gerontologist 2013;53:255–67.

22. Guedes MB, Lopes JM, Andrade AD, Guedes TS, Ribeiro JM, Cortez LC. Validation of the two minute step test for diagnosis of the functional capacity of hypertensive elderly persons. Rev Bras Geriatr Gerontol 2015;18:921–6.

23. Yasunaga A, Park H, Watanabe E, Togo F, Park S, Shephard RJ, et al. Development and evaluation of the physical activity questionnaire for elderly Japanese: the Nakanojo study. J Aging Phys Act 2007;15:398–411.

24. He H, Pan L, Wang D, Liu F, Du J, Pa L, et al. Normative values of hand grip strength in a large unselected Chinese population: evidence from the China National Health Survey. J Cachexia Sarcopenia Muscle 2023;14:1312–21.

25. Bandinelli S, Benvenuti E, Del Lungo I, Baccini M, Benvenuti F, Di Iorio A, et al. Measuring muscular strength of the lower limbs by hand-held dynamometer: a standard protocol. Aging (Milano) 1999;11:287–93.

26. Barry E, Galvin R, Keogh C, Horgan F, Fahey T. Is the timed Up and Go test a useful predictor of risk of falls in community dwelling older adults: a systematic review and meta-analysis. BMC Geriatr 2014;14:14.

27. Rydwik E, Bergland A, Forsen L, Frandin K. Psychometric properties of timed up and go in elderly people: a systematic review. Phys Occup Ther Geriatr 2011;29:102–25.

28. Podsiadlo D, Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc 1991;39:142–8.

29. Schaubert KL, Bohannon RW. Reliability and validity of three strength measures obtained from community-dwelling elderly persons. J Strength Cond Res 2005;19:717–20.

30. Goldberg A, Chavis M, Watkins J, Wilson T. The five-times-sit-to-stand test: validity, reliability and detectable change in older females. Aging Clin Exp Res 2012;24:339–44.

31. Rikli RE, Jones CJ. The reliability and validity of a 6-minute walk test as a measure of physical endurance in older adults. J Aging Phys Act 1998;6:363–75.

32. Zhao Y, Chung PK. Differences in functional fitness among older adults with and without risk of falling. Asian Nurs Res (Korean Soc Nurs Sci) 2016;10:51–5.

33. Beutner F, Ubrich R, Zachariae S, Engel C, Sandri M, Teren A, et al. Validation of a brief step-test protocol for estimation of peak oxygen uptake. Eur J Prev Cardiol 2015;22:503–12.

34. Dreher M, Walterspacher S, Sonntag F, Prettin S, Kabitz HJ, Windisch W. Exercise in severe COPD: is walking different from stair-climbing? Respir Med 2008;102:912–8.

35. Oliveros MJ, Seron P, Roman C, Galvez M, Navarro R, Latin G, et al. Two-minute step test as a complement to six-minute walk test in subjects with treated coronary artery disease. Front Cardiovasc Med 2022;9:848589.

36. Braghieri HA, Kanegusuku H, Corso SD, Cucato GG, Monteiro F, Wolosker N, et al. Validity and reliability of 2-min step test in patients with symptomatic peripheral artery disease. J Vasc Nurs 2021;39:33–8.

37. Węgrzynowska-Teodorczyk K, Mozdzanowska D, Josiak K, Siennicka A, Nowakowska K, Banasiak W, et al. Could the two-minute step test be an alternative to the six-minute walk test for patients with systolic heart failure? Eur J Prev Cardiol 2016;23:1307–13.

38. Benichou O, Lord SR. Rationale for strengthening muscle to prevent falls and fractures: a review of the evidence. Calcif Tissue Int 2016;98:531–45.

39. Leong DP, Teo KK, Rangarajan S, Lopez-Jaramillo P, Avezum A Jr, Orlandini A, et al. Prognostic value of grip strength: findings from the Prospective Urban Rural Epidemiology (PURE) study. Lancet 2015;386:266–73.

40. Taylor-Piliae RE, Latt LD, Hepworth JT, Coull BM. Predictors of gait velocity among community-dwelling stroke survivors. Gait Posture 2012;35:395–9.