Foot Tracking Devices and Technology

Imagine an athlete who wants to count every step while training. Foot tracking devices use force sensing and force sensing resistor technology. These devices measure movement and pressure. These tools help people get better at sports. They also help monitor health and make things safer. Recent studies show wearable devices help stop injuries. They also help make training better. The global market for these technologies was USD 2.77 billion in 2024. Experts think it will keep growing fast.

Key Takeaways

Foot tracking devices have sensors that watch movement and pressure. They help athletes get better and avoid getting hurt. These devices can go inside shoes or socks. This makes them simple to wear every day for health checks. Foot tracking devices give feedback right away. This helps coaches and doctors make smart choices about training and care. Smart insoles and socks help people with diabetes. They check foot pressure and temperature to stop ulcers from forming. GPS trackers in foot devices make people safer. Caregivers can see where someone is if they wander off. It is important to understand the data from foot tracking devices. Users should learn how to read this data for better health. Comfort and battery life matter when picking a foot tracking device. These things change how easy it is to use and collect data each day. As technology gets better, foot tracking devices will fit each person more. They will give advice based on how each person moves.

Foot Tracking Devices Overview

What They Are

Foot tracking devices have sensors and use technology to check how feet move, feel pressure, and where they are. These devices gather information about how someone walks, runs, or stands. Some use GPS to follow outdoor movement. Others use sensors like accelerometers and gyroscopes to count steps and see changes in direction. Many of these devices fit inside shoes or socks. This makes them simple to wear every day.

Companies are working hard to make these devices better. The table below lists some top companies and their main products.

Some devices are made for health. Others help athletes do better in sports. Devices like GPS SmartSole are good for healthcare. MatchTracker and GPS wearable devices help teams and coaches in sports.

Foot tracking devices are not the same as other wearable health tech. The table below shows some main differences.

Why They Matter

Foot tracking devices help in sports, health, and safety. They give quick feedback about movement and foot health. Coaches use these devices to watch athletes during games and practice. They can see how fast players move and how they turn. This helps make better training plans and stop injuries.

Doctors use these devices to check on patients with diabetes. The devices watch pressure and temperature in the feet. This helps stop foot problems and ulcers. Some devices help people who have trouble walking after a stroke. They show how a person moves and help doctors plan care.

Families use foot tracking devices to keep loved ones safe. Devices with GPS can track people who might wander, like those with dementia. Some systems send alerts if someone leaves a safe place.

Tip: Gait analysis helps doctors and coaches learn about movement. It is important for treating injuries and making performance better.

Researchers found that wearable sensors can watch movement and health right away. These sensors help find patterns that could cause injury. New technology makes these devices more exact, especially for fast sports movements.

Types of Foot Tracking Devices

Wearable Sensors

Wearable sensors are a big part of foot tracking devices. These sensors can go on shoes, socks, or skin. They gather information about how you move and where you put pressure. Many use force sensing resistors, like the ones from SOUSHINE. Force sensing resistors check how much force or pressure is on one spot. In foot tracking, they show how much pressure each part of the foot gets when you walk or run. This helps coaches, doctors, and researchers see how people move and spot possible problems.

IMUs

IMUs, or inertial measurement units, have accelerometers, gyroscopes, and sometimes magnetometers. These sensors watch how you move, how fast you go, and which way you turn. IMUs are in many sports and health devices. They help athletes and trainers count steps, check speed, and see changes in direction. Playermaker uses IMUs to give quick feedback during soccer practice. IMUs also help with rehab by tracking how someone moves after getting hurt.

Accelerometers & Gyroscopes

Accelerometers check changes in speed and direction. Gyroscopes watch how something turns and its position. When used together, they help devices record movement in detail. These sensors are in products like Omni One and SlimeVR. They help people keep track of steps, balance, and posture. Many wearable devices use these sensors for both sports and health.

Smart Insoles

Smart insoles go inside shoes and collect data about pressure, movement, and temperature. They work as foot monitors for people who need to watch foot health or performance. Many smart insoles give real-time updates about plantar pressure. This helps stop foot ulcers, especially for people with diabetes. Smart insoles are flexible and strong, so they work in many situations. They can also spot different ways of walking, which helps doctors give better care.

• Smart insoles can have some problems:
  • Heat and sweat in shoes can change how sensors work.
  • Not all insoles fit every shoe, which can make them hard to use.
  • Keeping data safe is important because these devices collect private info.

Note: Smart insoles give doctors and patients lots of details about foot pressure and movement.

Smart Socks

Smart socks use pressure sensors and sometimes EMG sensors to watch foot movement and health. These devices check how pressure spreads and how the foot touches the ground. Smart socks are made to be comfy, so people can wear them for a long time.

• Smart socks have special features:
  • They track how pressure spreads when you walk or run.
  • They watch how the bottom of the foot touches the ground.
  • They give more details than regular accelerometer devices.

Smart socks help athletes, patients, and researchers learn how the foot works with the ground. They help people get better at sports and keep their feet healthy.

GPS Trackers

GPS trackers help people know where someone or something is. They use signals from satellites to find a place. Many foot tracking devices use GPS for outdoor movement. Athletes use GPS trackers to see how far and fast they go. Coaches use this information to make better training plans. Families use GPS trackers to keep loved ones safe if they might wander.

Some GPS trackers go inside shoes, like GPS SmartSole. This makes them easy to wear and hard to lose. GPS trackers work best outside with a strong signal. Indoors, GPS may not work well because walls block signals.

• GPS trackers have different accuracy levels:
  • High-end GPS trackers can find a spot within 1 meter.
  • Regular GPS devices are usually right within 10 meters.
  • Accuracy depends on satellite signals, weather, and device quality.

Many sports teams use GPS trackers to watch players during games. These devices help track speed, distance, and direction changes. GPS trackers also help keep people safe by sending alerts if someone leaves a safe area.

Pressure Mats

Pressure mats are flat pads that measure how hard a foot pushes down. People use them in clinics and sports centers to study feet. Pressure mats help doctors and coaches see how someone walks or runs. They show where the most pressure is on the foot.

• Pressure mats are important for:
  • Checking how feet work and tracking plantar pressure in clinics and sports.
  • Giving information on foot mechanics, especially when someone is barefoot.
  • Showing details about foot strikes, like timing and where the foot lands.

Pressure mats help find problems with walking or running. They also help pick the right shoes or plan treatment for foot pain.

Optical & Thermal Sensors

Optical and thermal sensors use light or heat to watch foot movement and health. These sensors do not need to touch the skin. They can work in the dark or when someone stands still. Optical sensors use cameras and AI to study movement. Thermal sensors look for changes in heat from the foot.

Doctors use these sensors to watch for foot problems like ulcers. Sports trainers use them to study how athletes move. These sensors help make foot tracking devices more helpful in many places.

In-Shoe Sensors

In-shoe sensors are important in foot tracking technology. These sensors go inside shoes. They check how the foot and shoe work together when you walk, run, or stand. Many companies and scientists use in-shoe sensors to learn about movement and foot health in real life.

These sensors are made from bendable materials. They sit between your foot and the shoe. This helps them get good data. The sensors can check pressure at different spots on the foot. They also see how much force each part of the foot uses with every step.

Most in-shoe sensors use wireless technology. They connect to a small controller and a Bluetooth part. The controller is usually near the ankle. This setup lets the sensors send data to a phone, tablet, or computer. The sensors can measure things like:

• Average pressure on the foot
• Highest pressure with each step
• How pressure changes when walking or running

Some in-shoe sensors use ready-made parts. These parts include microprocessors and wireless senders. The system is easy to carry, so people can use it in many places. You can use it in clinics, on sports fields, or at home. The sensors work with many shoe types and on different surfaces.

Note: In-shoe sensors help doctors, coaches, and scientists see how people move in daily life, not just in labs.

A wireless chip can fit inside the insole. This chip collects data from the sensors and sends it without wires. The system can track many steps and movements. Some systems use one MEMS sensor. Others use more sensors for extra details.

In-shoe sensors have many uses. Athletes use them to get better at sports. Doctors use them to watch for foot problems, like high pressure that can cause ulcers. Families use them to help keep loved ones safe. These sensors work with other foot tracking devices to give a full view of movement and foot health.

In-shoe sensors keep getting better. New designs make them smaller and more comfy. As technology gets better, these sensors will help more people watch and protect their feet.

How They Work

Sensor Technology

Foot tracking devices use different sensors to watch movement. These sensors help collect data about walking, running, or standing. IMUs, accelerometers, reflective markers, and pressure sensors are common. IMUs and accelerometers need strong computers to work fast. Pressure sensors can fit in any shoe and are easy to use. Reflective markers need cameras but are not good for daily use.

• IMUs watch how you move and turn.
• Accelerometers check speed and direction changes.
• Pressure sensors measure force on the foot.
• Gyroscopic sensors find rotation and balance.
• Extensometers and goniometers check bending and angles.

Sensors can go in shoes, socks, or clothes. They help watch stepping rhythm, step size, weight spread, and timing. The signal difference between sensors on one foot is about 2 volts. The difference between both legs is about 1 volt. The average step phase difference between legs is about 0.15 seconds.

Tip: Pressure sensors can be replaced by users. This makes long-term monitoring easier.

Data Collection

Foot tracking devices gather data in different ways. GPS gives accurate outdoor movement data. Wi-Fi and Bluetooth sensors collect indoor movement details. Stereo vision and 3D counters make data more exact. These tools take 3D pictures and ignore things that do not matter.

• GPS finds location for outdoor movement.
• Wi-Fi and Bluetooth sensors gather indoor data.
• Stereo vision counts people and checks movement depth.
• Devices pick tracking metrics for each need.

Choosing the right metrics is important for good results. Devices watch and manage slowing down to see special movement needs. Watching movement all the time helps track changes and supports health and safety.

Real-Time Feedback

Foot tracking devices give real-time data with different feedback systems. Some use haptic feedback, sound alerts, or visual screens. Lechal Pods use haptic feedback for hands-free help and show steps, calories, and distance. Sensoria Smart Sock sends sound feedback and data to a phone. It uses three pressure sensors and an ankle device. Talking Shoe gives movement updates and can post to social media. It uses speakers for real-time talking.

Real-time data helps users change movement and watch progress. Coaches, doctors, and families use these systems to help with sports, health, and safety.

Applications

Sports & Athletics

Performance Analysis

Athletes use foot tracking devices to check how well they do. Coaches use GPS trackers, motion sensors, and accelerometers to watch speed and distance. These tools help teams see how players move and get better at training. Coaches change drills to stop players from working too hard. Teams use the data to lower injury risk and help athletes recover.

Wearable technology has changed how athletes train and improve. Location-based wearables follow movements and give data on speed and distance. Tracking systems help coaches learn what athletes need and make them better using data. Injury tracking looks at sports activities and helps teams help athletes heal faster. GPS signals can be blocked, so teams use more sensors for better results.

Gait Analysis

Gait analysis helps coaches and doctors study how athletes move. Devices record walking, running, and turning. Trainers use this data to find odd movement and stop injuries. Gait analysis helps athletes heal and get back to playing safely. Teams use these facts to help athletes do better and get hurt less.

Foot Health Monitoring

Diabetes Management

Foot health monitoring is important for people with diabetes. Diabetes can cause foot problems like ulcers. Devices in diabetic shoes, smart insoles, and socks watch pressure, temperature, and movement all the time. These devices send alerts if something is wrong, helping users avoid problems.

People use diabetic shoes with smart insoles to check foot pressure outside labs. Pressure feedback helps change how weight is put on the foot and lowers ulcer risk. Sensors track how well patients follow care plans and help them recover. Fun features keep users interested in watching their foot health.

1. High foot pressure can cause diabetic foot ulcers.
2. Smart insoles check foot pressure and help with diabetes care.
3. Pressure feedback helps users change what they do and wear to lower risk.

Doctors use these devices to watch foot health and stop problems. Patients get advice for shoes and activities. Remote monitoring helps doctors see recovery and act fast if needed.

Fall Detection

Foot tracking devices help find falls in older people. Falls are dangerous for people over 65. Sensors in shoes, socks, or mats watch for sudden movement changes. These systems alert caregivers when someone falls, helping quick recovery and lowering injury risk.

• Falls are a big danger for older adults.
• Monitoring systems find falls and tell caregivers.
• Insole systems have different sensor sizes and placements.
• These differences can make it hard to compare how well fall detection works.
• Ways to check fall risk with wearables are very different.

Doctors use foot health monitoring to check fall risk and watch healing after injury. Families use these devices to keep loved ones safe and act fast in emergencies.

Personal Security

GPS Tracking

Foot tracking devices help keep people safe, like those with dementia. GPS trackers in shoes or insoles let caregivers see where someone is right away. These devices lower risks from wandering and help after problems.

Families use GPS tracking to keep loved ones safe and let them be independent. Caregivers get alerts if someone leaves a safe area, so they can help quickly.

Boundary Alerts

Boundary alerts let caregivers set safe zones for patients. Devices send messages when someone goes past a set boundary. This helps keep people safe and stops injuries. Caregivers use boundary alerts to watch movement and act fast in emergencies.

Tip: Boundary alerts and GPS tracking work together to help families and caregivers feel safe.

Foot tracking devices help with health, healing, and safety in many ways. They help athletes get better, support diabetes care, and protect people who need help. Doctors, coaches, and families use these tools to watch foot health and stop injuries.

Key Features & Considerations

Data Interpretation

Foot tracking devices gather a lot of data. People need to know what this data means. Data cleansing fixes mistakes and removes strange results. Movement pattern analysis shows when and where people move most. Visualization techniques use maps, heatmaps, and 3D pictures to make things clear.

| Key Consideration | Description | | Data Cleansing | Making sure data is right, fixing mistakes, removing odd results, and changing formats. | | Movement Pattern Analysis | Shows busy times, favorite paths, and how people act by looking at the data. | | Visualization Techniques | Uses maps, heatmaps, and 3D pictures to show what the data means. |

Many devices have simple charts and graphs. These help coaches, doctors, and families see movement patterns. Good data interpretation helps people watch changes and act fast.

Tip: Clear pictures and charts help people find problems and see progress.

Indoor vs. Outdoor Use

Foot tracking devices can work in many places. Indoors, satellite signals do not work well. Devices may need special setups like labs or stadiums for good indoor tracking. Outdoors, devices can use satellite signals, which makes tracking better.

| Environment Type | Challenges Faced | Required Setup | | Indoor | No satellite signals for GNSS | Special stadium or lab needed for LPS | | Outdoor | Easier to use motion capture systems | Open sky needed for GNSS signals |

Some devices can switch between indoor and outdoor use. They use Wi-Fi or Bluetooth inside and GPS outside. This helps people keep tracking in different places. Coaches and doctors pick devices based on where they will use them.

Accuracy

Accuracy is important for foot tracking devices. Studies say mobile phones can track activity with average to great results. Some pedometer apps do not count steps as well as other devices. GPS systems are good at measuring distance, especially in sports.

• A review found mobile phones track activity with average to great accuracy.
• One study said some pedometer apps do not count steps as well as real pedometers.
• Research from the 1990s showed GPS is good for measuring distance, and later studies agreed it works well for sports.

People should check how accurate a device is before buying. Good accuracy helps athletes, patients, and families trust the data. Accurate devices help with health, safety, and doing better in sports.

Privacy & Subscriptions

Foot tracking devices keep and use private information. This can be things like where you are, how you move, and health facts. People should know how companies use this data and what could go wrong.

There are many privacy worries with these devices:

• Data may not be right for all ages or health groups. This can change health results if the device does not work for everyone.
• Police sometimes use wearable data to find where people go. This can cause unfair treatment for some groups, like racial or ethnic minorities.
• Many devices collect and share private data without telling users. Kids and older people may not know how much is being collected.
• Data leaks happen more now. When companies share data, it is easier for someone to steal or use it in the wrong way.

Companies try to fix these problems. They use encryption to keep data safe. Some let users pick what they want to share. Others have clear rules and let users erase their data. Parents can set limits on kids’ devices. Some devices do not share data with other companies.

Foot tracking devices often need a subscription. Subscriptions give extra things like cloud storage, better reports, or alerts. People should know what comes with a subscription and how it changes their data.

People should read the rules before paying for a subscription. Some services keep data after you stop paying. Others need a monthly fee for important features. People should check if they can delete data and if the company shares it.

Tip: Check privacy settings often and ask if you do not know how your data is used.

Privacy and subscriptions are important in foot tracking technology. People who learn about these things can make smart choices and keep their data safe.

Integration with Other Tech

Mobile Apps

Mobile apps are important for foot tracking technology. These apps connect to wearable devices. Users can see their data right away. People set goals and track steps with the app. The app gives feedback on progress. Sensors in wearables measure health numbers. Data moves wirelessly to the app. Users look at reports and spot trends. They can change health goals if needed.

• Mobile apps help users:
  • Set goals for walking or running.
  • Track their activity every day.
  • Compare progress with friends or family.
  • Use reminders to stay active.

Mobile apps use artificial intelligence to learn habits. The app changes advice for each user. During health emergencies, apps adjust to new routines. Social features let users compare results with others. This helps people stay motivated and active.

Mobile apps make wearable devices easy to use daily. They help users stay interested and reach their goals.

Wearable Devices

Wearable devices include smartwatches, fitness bands, smart insoles, and smart socks. These devices collect movement, pressure, and location data. People wear them on feet, wrists, or ankles. Wearables send data to apps or computers. This helps users and experts see how someone moves.

• Types of wearable devices:
  • Smart insoles track foot pressure.
  • Smart socks measure how feet touch the ground.
  • Fitness bands count steps and distance.
  • GPS trackers show location.

Wearable devices work with other technology. A smart insole sends data to a phone app. A fitness band shares step counts with health platforms. Coaches use wearables to watch athletes practice. Doctors check on patients at home with these devices. Wearables help people make better health and safety choices.

Cloud Analytics

Cloud analytics changes how people use foot tracking data. The cloud stores data from wearable devices. Coaches and trainers see real-time data and give feedback fast. Over time, the cloud tracks trends and helps adjust training plans.

• Cloud analytics helps in many ways:
  • Collects and studies data from wearables in real time.
  • Gives insights into movement in stores, gyms, or clinics.
  • Helps businesses see when and where people walk most.
  • Uses prediction tools to plan for busy times or events.

Retailers use cloud analytics to learn about customer movement. They decide where to put products or staff stores. Real estate and marketing teams use footfall data to pick locations. Cloud analytics makes it easier to use wearable device data for many needs.

Cloud analytics helps users and experts make smart choices using real data from wearable devices.

Real-World Examples

Sports

Athletes and coaches use wearable devices to help with training. These tools help players get better and avoid getting hurt. Playermaker has a system that clips onto shoes. It tracks every move during soccer practice. Coaches look at the data to see how players run and kick. In basketball, sensors like SOUSHINE measure pressure and impact. They check jumps and landings. Trainers can see if a player puts too much force on one foot. This helps stop injuries like shin splints or knee pain.

• Runners use sensors to watch how their feet hit the ground.
• Soccer teams use Playermaker to track speed and turns.
• Basketball coaches use pressure sensors to spot unsafe landings.

Coaches use feedback from wearable devices to change training and keep athletes safe.

Health

Wearable devices are important for watching health. Smart insoles and socks, like SOUSHINE, track pressure and temperature in feet. Doctors use this data to look for foot ulcers in people with diabetes. Patients wear these devices at home and send results to doctors. This helps doctors act fast if there is a problem.

A person with diabetes used smart insoles every day. The device sent alerts when pressure stayed high in one spot. The health team called and suggested new shoes. This helped the patient avoid a bad foot ulcer.

• Wearable socks track temperature changes that may mean infection.
• Smart insoles help doctors see if patients follow care plans.
• Health teams use data from wearables to give advice and stop problems.

Security

Families and caregivers use wearable tech to keep people safe. GPS trackers like Omni One and in-shoe devices like SlimeVR show location in real time. A family put a GPS tracker in a grandparent’s shoe. When the grandparent left the safe area, the device sent an alert to the caregiver’s phone. The family found the grandparent fast and brought them home.

• Caregivers use GPS trackers for people with memory loss.
• Security teams use in-shoe sensors to watch movement in special areas.
• Wearable devices send alerts when someone leaves a safe zone.

Wearable technology helps families worry less and keeps people who need help safe.

Choosing the Right Device

Accuracy

Accuracy is very important when picking a foot tracking device. Devices that are more accurate give better movement and health data. Coaches need accurate devices to watch athletes train. Doctors use good data to help make health choices. Some devices have special sensors to make them more exact. IMUs and GPS trackers can work together for better results. People should check if a device counts steps, pressure, and location well. A device that is very accurate helps with health checks and gives better results.

Tip: Look at product tests and what users say to see if a device works well in real life.

Comfort

Comfort is important for using foot tracking devices often. If a device feels good, people will use it more. Smart insoles and socks go inside shoes or around the foot. These designs let people wear them for many hours. Light materials and bendy shapes make them more comfy. Some devices have straps you can adjust or soft padding. People should try different devices to see which one feels best. Comfort makes it easier to use the device every day and helps with health checks.

• Comfortable devices:
  • Stop skin from getting sore.
  • Let you wear them longer.
  • Help you get better health results.

Note: If a device is not comfy, people may stop using it, which can make health checks harder.

Battery Life

Battery life is important for people who need to track health all day. Devices with long battery life let you track health without charging a lot. Some GPS trackers can last for days on one charge. Smart insoles and socks usually need charging after one day. People should check how long the battery lasts before buying. A longer battery life means you do not have to worry about missing health data.

Tip: Set reminders to charge your device often. This helps you keep tracking your health.

Picking the right device means looking at accuracy, comfort, and battery life. Each part helps you track health and manage it better.

Price

Price plays a big role when people choose a foot tracking device. Each device comes with its own cost, and the price often matches the features it offers. Some devices cost less and give basic tracking. Others cost more and offer advanced features like real-time feedback, cloud storage, or extra sensors.

People can find foot tracking devices in many price ranges. The table below shows common types and their usual price points:

A basic pedometer costs the least. It counts steps and shows simple data. Smart insoles and socks cost more because they have sensors and connect to apps. GPS trackers help with location and safety, so they often cost more than basic models. Advanced wearables, like those used by athletes or in clinics, cost the most. They give detailed data and work with cloud analytics.

Tip: People should think about what features they need before buying. Paying more does not always mean better results for everyone.

Some devices need a one-time payment. Others need a monthly or yearly subscription for extra features. Subscriptions may include cloud storage, advanced analytics, or real-time alerts. People should check if the device needs a subscription and what it covers.

• One-time purchase: Pay once, use basic features.
• Subscription: Pay each month or year for more features.

People should also look at the total cost over time. A device with a low price but a high subscription fee may cost more in the long run. Some companies offer bundles or discounts for families or teams.

When choosing a device, people should ask these questions:

1. What is the upfront cost?
2. Does the device need a subscription?
3. What features come with the price?
4. Will the device last long enough to be worth the cost?

A higher price may bring more features, but not everyone needs them. People should match the device to their needs and budget. Comparing devices and reading reviews can help people make a smart choice.

Note: Price matters, but the best device is the one that fits the user’s needs and goals.

Future Trends

Sensor Advances

Sensor technology is always getting better. New sensors can now track more about how feet move. Some sensors check pressure in many spots on the foot. Others notice when the temperature changes. These new sensors help doctors and coaches see small changes in walking or running. Companies are making sensors smaller and lighter now. This makes it easier for people to wear these devices every day. Some sensors can even work if they get wet or dirty. These updates help more people use foot tracking devices at home, in sports, or in clinics.

Note: Smaller sensors make it easier to use foot tracking devices in different places.

AI & Analytics

Artificial intelligence, or AI, helps foot tracking devices give better feedback. AI looks at the data from sensors and finds patterns. It can notice changes in walking that might mean a health problem. AI can also give tips to help people move better. Many devices now use cloud analytics. This means the data goes to a safe server. Coaches and doctors can see reports right away. AI can also warn about risks before they get worse. For example, AI can warn if someone might fall or get a foot injury soon.

AI and analytics help people make better choices for sports and health.

Personalization

Personalization is a big new trend in foot tracking technology. Devices now learn how each person moves. They use this information to give advice that fits each user. For example, a device might suggest new shoes or a new way to walk. Some devices let users set their own goals. Others change alerts based on what the user does each day. Personalization helps people get more from their devices. It also helps doctors and coaches give better care.

• Devices can:
  • Watch how each person walks.
  • Suggest changes to lower the chance of getting hurt.
  • Remind people to check their health every day.

Personalized feedback helps people stay active and keep their feet healthy. As technology gets better, foot tracking devices will give even more helpful advice for everyone.

Foot tracking devices are useful for sports, health, and safety. These tools show simple data about how feet move and stay healthy. Athletes use them to get better at training. Doctors use them to check for health issues. Families use them to help keep loved ones safe.

• People can find out more by looking at new products.
• They can talk to experts to get help.

Learning about new technology helps people make smarter choices.

FAQ