A pedometer or step counter is a device, in modern times usually portable and electronic or electromechanical, that counts each step a person takes by detecting the motion of the person's hips. Because the distance of each person's step varies, an informal calibration performed by the user is required if a standardized distance (such as in kilometres or miles) is desired.

Used originally by sports and physical fitness enthusiasts, pedometers are now becoming popular as an everyday exercise measurer and motivator. Often worn on the belt and kept on all day, it can record how many steps the wearer has walked that day, and thus the kilometres or miles (distance = number of steps × step length). Some pedometers will also erroneously record movements other than walking, such as bending to tie one's shoes, or road bumps incurred while riding a vehicle, though the most advanced devices record fewer of these 'false steps'. Step counters can give encouragement to compete with oneself in getting fit and losing weight. A total of 10,000 steps per day, equivalent to 5 miles (8.0 km), is recommended by some to be the benchmark for an active lifestyle, although this point is debated among experts^[1][2]. Step counters are being integrated into an increasing number of portable consumer electronic devices such as music players and mobile phones.

Recently, exercise enthusiasts have observed that an advanced Global Positioning System (GPS) receiver with an odometer mode serves as a very accurate pedometer for outdoor activities. While not truly counting steps (no pendulum is involved) an advanced GPS odometer can reveal the accurate distance traveled to within 1/100 of a mile (depending on the model, perhaps 1/1000 of a mile). One thousandth of a mile is approximately the distance of a single pace or two steps.

The modern definition of the international mile traces back to the Roman military method of keeping track of how far a soldier had traveled on foot. The Latin "mille passus" is literally "a thousand paces" where 1 pace = 2 steps. The international mile (5,280 US feet) is somewhat longer than the original Roman mile (4,854 US feet). As with the mile, the definition of "foot" has changed many times.

Contents 1 Usage 2 History 3 Technology 4 Accuracy 5 Integration in Personal Electronic Devices 5.1 Apple iPod Nano 5.2 Nike&iPod 5.3 NTT DoCoMo Fujitsu Pedometer Phone 5.4 Nokia 5500 Sports Phone 5.5 Nokia Sports Tracker 5.6 Nokia Step Counter 5.7 Sony Ericsson W710 walkman phone, W580 walkman phone 5.8 Nintendo DS 6 References 7 External links

[edit] Usage

Pedometers can be a motivation tool for people wanting to increase their physical activity. Various websites exist to allow people to track their progress, however, many will also find entering their daily step count and a heart comter onto a calendar to be motivational as well. Pedometers have been shown in clinical studies to increase physical activity, and reduce blood pressure levels and Body Mass Index. A study published in the Journal of The American Medical Association Nov. 2007^[3] concluded, “The results suggest that the use of a pedometer is associated with significant increases in physical activity and significant decreases in body mass index and blood pressure.”

A daily target of 10,000 steps was first proposed.^[4] The target has been recommended by the US Surgeon General and by the UK Department of Health.^[5][6] The main criticisms of setting a universal target are that it is not achievable for older persons with mobility problems or people with chronic diseases, but on the other hand, the target is too low for children.^[5]

One criticism of the pedometer is that it does not record intensity, but this can be done by making step goals time limited (for example, 1000 steps in 10 minutes counts as moderate exercise).^[7]

[edit] History

The Romans used an odometer calibrated to steps to measure distances for military and civil purposes, although technically this is not a step counter.^{[citation needed]} Leonardo Da Vinci envisioned a mechanical pedometer as a device with military applications.^[8][9] The modern all-mechanical pedometer was introduced later to the Americans by Thomas Jefferson.^[10] Jefferson obtained a unit from France, but it is not known if he modified the design, or introduced it to the US as is. Although this pedometer is widely attributed to Mr. Jefferson,^[11][12] proof is difficult to obtain as he never applied for any patents on any of his inventions.^[13]

In 1965, a pedometer called a manpo-kei (meaning "10,000 steps meter" 万歩計) was marketed in Japan by Y. Hatano.^[14]

Revision needed-Y. Hatano promoted "manpo-kei pedometers" from 1985, after his research was accepted as proving that 10,000 Steps A Day was the proper balance of caloric intake and activity-based caloric expenditure to maintain a healthy body, but Yamasa Tokei Keiki's founder, Yasuji Kato's father, manufactured pedometers recognized to be accurate, and, later named them, "manpo-kei." ^[15]

[edit] Technology

The technology for a pedometer includes a mechanical sensor and software to count steps. Early forms used a mechanical switch to detect steps together with a simple counter. If one shakes these devices, one hears a lead ball sliding back and forth, or a pendulum striking stops as it swings. Today advanced step counters rely on MEMS inertial sensors and sophisticated software to detect steps. These MEMS sensors have either 1-, 2- or 3-axis detection of acceleration. The use of MEMS inertial sensors permits more accurate detection of steps and fewer false positives. The software technology used to interpret the output of the inertial sensor and "make sense of accurate steps" varies widely. The problem is compounded by the fact that in modern day-to-day life, such step-counters are expected to count accurately on locations where users frequently carry their devices (attached to the belt, shirt/pants pocket, hand bag, backpack).

[edit] Accuracy

The accuracy of step counters varies widely between devices. Typically, step counters are reasonably accurate at a walking pace on a flat surface if the device is placed in its optimal position (usually vertically on the belt clip). Although traditional step counters get affected dramatically when placed at different angles and locations, recent advances have made them more robust to those non-ideal placements. Still, most step counters falsely count steps when a user is driving a car or makes other habitual motions that the device encounters throughout the day. This error accumulates for users with moderate commutes to work.^[16] Accuracy also depends on the step-length the user enters.

Best pedometers are accurate to within ± 5% error.^[17][18]

[edit] Integration in Personal Electronic Devices

[edit] Apple iPod Nano

The 5'th generation iPod Nano by Apple features an integrated pedometer. ^[19]

[edit] Nike&iPod

Apple and Nike, Inc. offer the Nike+iPod Sports Kit, which uses a shoe sensor that communicates with a wireless MP3 Player receiver to transmit workout information such as elapsed time, distance traveled, and calories burned.

[edit] NTT DoCoMo Fujitsu Pedometer Phone

This is the first integrated phone with a pedometer that works 24 by 7 and counts step like an Omron pedometer. The sensor is made by ADI. This handset was introduced in Japan in 2004 and has sold over 3 million units.

[edit] Nokia 5500 Sports Phone

The Nokia 5500 Sports Phone uses an embedded 3 axis MEMS inertial sensor to detect the steps a user takes. The pedometer application tracks steps taken, time elapsed and distance traveled. However the application cannot run continuously as it drains the phone's battery and is therefore of limited use.

[edit] Nokia Sports Tracker

Nokia Sports Tracker features pedometer for Nokia Symbian phones with a Accelerometer. Accelerometers are included in phones to save correct orientation on photos and to improve gps positioning feature.

[edit] Nokia Step Counter

Nokia Step Counter is a free application available at Nokia Beta Labs which works on a wide range of N-Series Nokia phones. The pedometer application tracks steps taken, time elapsed and distance traveled. This application can be left running all day as it is not a huge drain on the battery.

[edit] Sony Ericsson W710 walkman phone, W580 walkman phone

The Sony Ericsson W710 and W580 walkman phones use embedded 2 axis MEMS inertial sensors to detect the steps a user takes. The W710 is a clamshell phone and displays the user's steps on the external display. The W710 must be closed in order for it to count steps. When the step counter is activated, it counts detected steps during the day, and at midnight it stores the counter in a day-by-day history and resets it to zero.

[edit] Nintendo DS

On May 26, 2009, Nintendo released the Nintendo DS title Personal Trainer: Walking, which includes two pedometers. They connect to the game card via infrared signals.

On September 12, 2009, Nintendo released Pokémon HeartGold and SoulSilver in Japan. Each game comes bundled with a device called a Pokéwalker, which functions as a pedometer and allows players to transfer one Pokémon from their game to the Pokéwalker via infrared signals. Unlike the Personal Trainer: Walking pedometers, the Pokéwalker features a small LCD screen and multiple buttons. Walking with the Pokéwalker earns experience points for the Pokémon and in-game currency.^[20]

[edit] References

[edit] External links

Wikimedia Commons has media related to: Pedometers

• [1] Pedometers and brief e-counseling: increasing physical activity for overweight adults] from nih.gov
• Pedometer article from rochester.edu
• Pedometer Information Sheet fron Alberta Centre for Active Living
• Sportline Pedometer Descriptions & Specifications