How does pedometer count steps

Other researchers are conducting similar interventions in clinical populations. Kaiser Permanente adopted the 10, steps pedometer program originally developed by Minnesota Health Partners [ 53 ], for use in a managed care setting [ 54 ].

Some of these programs may lack an element of personal accountability to a researcher that has usually been present in most of the published research on pedometer interventions. However, by substituting phone calls and emails in place of personal face-to-face contact it appears that they are effective at increasing physical activity. In the future, more research is needed to determine the health outcomes and cost-effectiveness of such programs. The first use of pedometers for physical activity surveillance was conducted in Switzerland in — Sequira et al.

They used the Pedoboy, a small, low-cost, mechanical step counter made in Germany. The step counter was worn for 1 week, and the average number of steps per day decreased from 11, to and from to for men and women, respectively, in the youngest to the oldest age categories. Thus, males tended to take more steps than women, except in the oldest age categories. Occupation was also found to be associated with daily steps. McCormack et al. A subset of the original participants agreed to take part in the pedometer study.

Men accumulated more steps per day 10, steps than women steps , and younger adults accumulated more steps per day than older adults. This annual survey has been conducted by the Ministry of Health, Labor, and Welfare since , and the Yamasa Digi-walker pedometer steps since In November , 1-day step counts were administered in a nationally representative sample of individuals.

Similar to other countries, there was an age-related decline in daily steps. This procedure of censoring steps may help in harmonizing ActiGraph data and Yamax Digi-walker data. However, the ActiGraph step counts are quite similar, on average, to those obtained with the ankle-worn StepWatch which is often regarded as a suitable criterion for step counting [ 58 ].

They were recruited through their parents using random digit dialing and mailed a step counter and a data collection package. Girls were found to take fewer steps per day than boys 10, vs. Studies on convenience samples of children in 13 countries have found that they typically have higher mean daily step counts than adults [ 60 ]. This finding is generally consistent with the US Department of Health and Human Services DHHS physical activity guidelines calling for at least 60 min of aerobic activity per day in children, whereas in adults the guidelines call for accumulating min of moderate intensity physical activity per week, 75 min of vigorous physical activity per week, or a combination of the two in bouts of 8—10 min or longer [ 61 ].

In our view, step counters might be able to assess the likelihood that an individual is meeting the guidelines, but they cannot determine if the guidelines are being met.

This is due to the inability of most step counters to measure frequency, intensity, and duration, as well as their inability to capture bicycling, swimming, and resistance training. In addition to steps per day, pedometers can also provide information on cadence.

Cadence is an important variable because it can be used to estimate walking speed and rate of energy expenditure. For instance, 30 min of continuous walking at 2. Faster and slower walking speeds yields higher and lower cadences, respectively. However, cadence is not the same thing as step accumulation per minute, in free-living adults.

Cadence can be thought of as a fairly instantaneous rate of stepping measured over a few strides. Step accumulation per minute, on the other hand, refers to the total number of steps taken during a 1-min epoch [ 63 ]. Thus, it is difficult to determine cadence when using 1-min epochs in free-living individuals, due to the presence of brief, intermittent bouts of walking. However, it seems reasonable to suggest that step accumulation rates can provide a crude approximation of the intensity level.

For instance, the StepWatch uses the step accumulation rates to classify physical activity intensity into one of three zones low, medium, and high activity.

Weyand et al. They then developed a formula using foot—ground contact time to predict speed over a wide range of speeds, from slow walking to sprint running. Taken together, this implies that extremely accurate estimates of EE are possible with a shoe-mounted device and simple anthropometric measurements. Wearable medical devices are now being designed for use in clinical research settings.

The FDA is concerned about the safety, precision, and claimed benefits of such devices. However, unlike other medical devices that assess vital signs and clinical biomarkers e.

The ability of wearable devices to continuously store vast amounts of information on small, inexpensive computer chips has fundamentally changed the field of physical activity assessment. It alleviates concerns about physical activity questionnaires being too subjective, and people being unable to recall how much incidental activity they performed over the course of a day.

In order for step counting to become a standard component of medical care, several things would need to occur:. Longitudinal, prospective cohort studies must demonstrate that daily stepping predicts the incidence of future disease. Steps per day must be a rigorously validated metric, harmonized across multiple step-counting devices.

FDA clearance procedures must be established for wearable medical devices that count steps. Reimbursement codes for objective assessment of physical activity using wearable medical devices would also speed the adoption of step counting in medical care.

In this article, we stated that a common definition of a step is one that involves lifting the foot or prosthetic limb off the ground, moving it to a new location, and putting it back down again. The ideal location for accurately measuring steps seems to be the ankle or foot.

However, waist-mounted devices are accurate enough that they can yield useful information on the relationship between steps per day and health outcomes.

Currently, more studies are needed that examine the step counting accuracy of wrist-worn devices. By using step counters in physical activity interventions, we have learned that they facilitate behavior change and can be helpful in motivating inactive individuals to increase their activity levels by about steps per day the equivalent of walking 1 mile.

These new medical devices will interface with the electronic medical record and require new levels of privacy control. High levels of accuracy, especially among older and disabled patients who walk slowly and with altered gait, will be of paramount importance for wearable medical devices. David R. Bassett, Jr.

Lindsay P. Toth, Samuel R. LaMunion, and Scott E. Crouter have no competing interests. No financial support was received for the development and preparation of this manuscript.

National Center for Biotechnology Information , U. Sports Medicine Auckland, N. Sports Med. Published online Dec Toth , Samuel R. LaMunion , and Scott E. Samuel R. Scott E. Author information Copyright and License information Disclaimer. Corresponding author. This article has been cited by other articles in PMC. Abstract Step counting has long been used as a method of measuring distance. Key Points Steps are a fundamental unit of human locomotion, and thus are a preferred metric for quantifying physical activity.

Many step-counting devices are available for both consumer and research use, but the need for industry standardization is acknowledged and must be addressed in order to harmonize data. Open in a separate window. Table 1 Number of Fitbit devices sold worldwide from to Year No. History of Step Counting Step counting began as a method of estimating distance.

Types of Step Counters There are many different types of step counters. Waist-Worn, Spring-Levered The traditional step counter was designed to be worn at the waist, attached to the belt or waistband.

Waist-Worn, Accelerometer More recent waist-mounted step counters use an internal mechanism consisting of a piezoelectric or piezo-resistive accelerometer typically tri-axial. Thigh The activPAL monitor is designed to be taped to the thigh. Ankle The most accurate step counter for walking is the StepWatch 3 device, worn on the ankle [ 23 , 24 ]. Foot Shoe-mounted step counters are designed so that contact of the heel with the ground causes a step to be recorded. Wrist Recently, wrist-worn activity trackers have been designed that measure steps e.

Why Count Steps? Classification of Steps per Day Pedometers can be used as an overall index of how active a person is. Table 2 Steps-per-day categories and classification system of Tudor-Locke and Bassett [ 33 ]. Relationship between locomotive speeds and rates of caloric expenditure. What is a Step? Table 3 Steps-per-day categories and prevalence of metabolic syndrome in Australian men and women.

Prospective Observational Studies Prospective, observational studies are currently being conducted that use wearable monitors to assess physical activity in large cohorts Table 4. Table 4 Prospective, longitudinal studies using wearable activity monitors to assess physical activity and examine it in relation to disease endpoints.

Longitudinal Intervention Studies Beginning in the mids, step counters began to be used in behavioral interventions designed to increase physical activity in inactive, outpatient adults. Step Counting for Physical Activity Surveillance The first use of pedometers for physical activity surveillance was conducted in Switzerland in — Beyond Step Counting: Measurement of Gait Parameters In addition to steps per day, pedometers can also provide information on cadence.

Potential for Integrating Step Counting into Medical Practice Wearable medical devices are now being designed for use in clinical research settings. In order for step counting to become a standard component of medical care, several things would need to occur: Longitudinal, prospective cohort studies must demonstrate that daily stepping predicts the incidence of future disease Steps per day must be a rigorously validated metric, harmonized across multiple step-counting devices FDA clearance procedures must be established for wearable medical devices that count steps Health Information Privacy and Portability Act HIPPA -compliant file structures must be used Step data must be integrated seamlessly into the electronic medical record EMR.

Summary In this article, we stated that a common definition of a step is one that involves lifting the foot or prosthetic limb off the ground, moving it to a new location, and putting it back down again. Compliance with Ethical Standards Ethical approval and consent to participate Not applicable.

Consent for publication Not applicable. Competing interests David R. Funding No financial support was received for the development and preparation of this manuscript. References 1. Stunkard A. In general, keeping your smartphone in your front pocket yields the most accurate results. Pedometers are great tools, but they are just that - a tool.

They can help you measure where you are on the path to your goals whether it's 10, steps or just extra steps. They can motivate you to push further and longer, but they only work if you do the walking. Tracking your steps can help you measure your progress, which can be quite motivating. Exercise Exercise Equipment and Clothing How Pedometers Work Learning how pedometers work provides a great tool for achieving fitness goals. Recording Steps Essentially, a pedometer records the steps you walk.

Pedometer vs. Step Tracker Apps Old fashioned pedometers clipped onto belts or were worn on a wristband. Choosing a Pedometer Pedometers are goal-oriented devices that act as both a means for measurement and incentive to improve the number of steps you take each day. Old fashioned, clip-on pedometers can be a good choice for: People who do not want their step history collected in a database People who have a hard time remembering to keep their smartphones with them Kids who need to be encouraged to take more steps and be more active Giveaways from gyms, wellness organizations, or as employee gifts.

Are Pedometers Accurate? Correct Pedometer Usage Pedometers are effective only if they are used correctly. Body Placement Tucking the pedometer into your purse, your backpack or your pocket is not ideal. Correct Step Tracker Usage The app you use for a step tracker will provide tips for the ideal smartphone placement on your body to track steps.

For now, from the results of this study, consumers can assume that this is a trustworthy brand to use. The results of this study also suggest that pedometers worn on the waist are more accurate with counting steps than those worn on the wrist. It has been suggested in previous research that pedometers worn on the wrist might not register small steps 9.

Participants were told to exaggerate arm movements during the first couple of small steps, as a previous study has suggested this may yield more accurate results for activity trackers worn on the wrist 9.

Also, the fast walking pace of 3. Conversely, it has also been suggested that wrist pedometers may overestimate steps when people engage in activities that require a lot of arm movement such as racquet sports 9. Another important item for users to consider is that the most accurate pedometer in this study only had one function: counting steps. This is in contrast to the other three activity trackers that not only count steps, but also track other functions. Consumers ultimately must decide what features they want in a pedometer or activity tracker.

If buyers do not care as much about the accuracy of the steps, and they want to have more features to track, then they can choose the less accurate activity trackers used in this study. Further research into the accuracy of other functions available on activity trackers should be conducted. It is reasonable to conclude that it is more convenient and quicker to check a device that is easily accessible on the wrist than it is to check a pedometer worn on the waistband, which has to be taken off in order to be checked.

Yet another point to consider is that from a health standpoint, one can argue that it is better to under-estimate steps than over-estimate, because the result is that people engage in more activity. If a pedometer regularly overestimated steps, it would cause a person to think they did more work than the reality.

On the opposite spectrum, however, underestimating steps may lead people to exercise more, which is also misleading but not necessarily a dangerous or harmful result. This would be a regular occurrence with the three brands that significantly underestimated steps in this study.

Another compelling area of future research should compare the accuracy of pedometers on treadmills versus their accuracy in free walking conditions during activities of daily living. In a study that examined free walking conditions, participants walked on an outdoor track at a self-selected pace 8.

The other 8 brands of pedometers, however, were accurate 8. Another study compared pedometer accuracy on a sidewalk and rubberized outdoor track, with no significant differences in accuracy found between these two conditions 2. No studies to date have compared free walking conditions with treadmill walking in the same study. It is acknowledged that a limitation of this study is the small number of participants recruited, the limited age range of participants, and the unequal number of recruited men and women.

Also, having each participant undergo a second test on a different day could have determined the test-retest reliability of the pedometers. Finally, only four pedometer brands were studied, even though there are numerous others available.

Therefore, future research should continue to study and compare the accuracy of the latest pedometers available for users today, including those from this study as well as the numerous others on the market. The findings should then be used to refine and improve the accelerometer and GPS systems used to measure steps, adjusting the sensitivity threshold as needed so that consumers can trust the accuracy of pedometers.

The specific brands tested constitute a novel area of study for pedometer accuracy. Confounding variables were limited as much as possible through the use of a treadmill, a healthy population with a normal gait, and having participants perform the same protocol. These results refute the hypothesis that cost and accuracy would have a directly proportional relationship. The importance of increased research and resources for improving pedometer accuracy cannot be emphasized enough.

Part of the reason is based on how they work. Some also use gyroscopes to determine the direction and rotational movement. When your fitness band interprets the data from its motion sensors, it is supposed to ignore motions that are not associated with walking.

For example, banging on nails with a hammer can create vibrations that may be close enough to step motions that the data is misinterpreted as walking. More subtle movements can also cause errors. Washing your hands, preparing food, petting your cat, or using a computer mouse can also result in steps being registered by your device. Vibrations that affect all or part of your body can also result in inaccurate step counts.

For example, riding in a car, bus, train, or subway can create motions that are interpreted as steps. You can add hundreds of steps while driving your car for an hour or less. As you go higher, air pressure decreases. For example, riding in an elevator can register as walking up flights of stairs. Air pressure changes from riding in a car or other moving vehicle can throw off the count, as can entering and exiting high-rise buildings that have air pressure that is different from the outside.

Even rapid changes in weather can register as climbing floors. So trackers are not perfect at counting steps taken or flights climbed.