Instrumented insoles are specialized shoe inserts that contain sensors and other technology to measure various aspects of a person’s movement and foot pressure distribution. The sensors in the insoles collect data on things like gait analysis, pressure distribution, and foot motion, which can then be analyzed to provide valuable information about a person’s foot health, balance, and overall movement patterns. Instrumented insoles can be used in a variety of settings, including sports training, medical rehabilitation, and research. They can help athletes improve their performance by providing feedback on their stride and foot pressure distribution. They can also aid in the diagnosis and treatment of foot-related medical conditions, such as diabetic foot ulcers, plantar fasciitis, and flat feet. In addition to the sensors, instrumented insoles may also contain other technologies such as Bluetooth connectivity, accelerometers, and gyroscopes. This allows the insoles to communicate with other devices, such as smartphones, computers, or medical equipment, to provide real-time data and analysis.
Instrumented insoles can be used as a real-time biofeedback tool which helps patients to actively correct their gait cycle and posture. This technology can be used for clients who have regular low-back pain and also for those who have undergone any sort of lower limb surgery. Any lower limb surgery (from the femur to the foot), either elective or traumatologic, is followed by a partial weight bearing (PWB) period on the treated limb, which has multiple aims widely described and analyzed in the literature. Most notably, PWB permits correct osteo-integration; reduces implant failure, aseptic mobilization, and implant breakage; and promotes wound healing and pain control. At the same time, the PWB period prevents prolonged discharge (non–weight bearing) and related complications on the operated limb.
In addition to traditional monitoring methods, new feedback methods have been developed on the basis of scales or tactile/verbal feedback from physical therapists, although they remain extremely operator-dependent and are scarcely reproducible. Initially, these methods used plates capable of measuring the patient’s weight bearing force: unfortunately, those systems were cumbersome and thus used only in laboratories for research purposes. Recently, with the development of more advanced technologies and force-sensitive resistors (FSRs), it has been possible to design simpler tools that can even be worn as footwear soles and linked to wearable control units.
Some of the various ways instrumented insoles are useful are as follows –
- Post-operative TKR – A systematic review done by Ngueleu et al and Gianluca et al have reported strong improvement in rehabilitation with instrumented insoles. The technology helps individuals to actively correct the amount of load/weight load on their operated limb. This helps to reduce the chances of implant failure and overall increases the success rate of their rehabilitation.
- Post-operative lower limb fractures – The biofeedback helps patients to avoid unwanted or harmful movements on the foot which inturn facilitates correct/wanted movements for better rehabilitation. It also provides feedback regarding weight distribution and loading.
- Reducing the risk of fall – Instrumented insoles can detect abnormal gait patterns, such as uneven pressure distribution, which may indicate an increased risk of falls. By alerting the user or their caregiver to these patterns, steps can be taken to address them.
- Providing balance feedback – Insoles can also provide feedback on the user’s balance, which can help them adjust their gait to maintain stability. This feedback can be especially useful for older adults or individuals with mobility issues who may have difficulty sensing their own balance.
- Rehabilitation for parkinsonism – The research is still ongoing but the results for the use of instrumented insoles for the detection of gait variables have been phenomenal. Many studies have shown that instrumented insoles are a valid tool for the analysis of PD gait.
- Sports – Instrumented insoles can provide athletes with real-time feedback on their foot pressure, balance, and movement patterns, allowing them to make adjustments on the fly. This feedback can be especially useful for athletes who are working on improving their technique or addressing specific areas of weakness.
- Foot Posture – Abnormal foot postures during gait are common sources of pain and pathologies of the lower limbs. Measurements of foot plantar pressures in both dynamic and static conditions can detect these abnormal foot postures and prevent possible pathologies.
Now, let us go a little in depth on how instrumented insoles can be a great tool for improving postural balance and correcting gait abnormalities.
- Postural balance – Postural balance refers to the ability of an individual to maintain a stable and upright position while standing, sitting, or moving. Good postural balance allows individuals to maintain a stable and upright posture while performing daily activities, such as walking, reaching, or standing for extended periods. Impaired postural balance, on the other hand, can result in falls, injuries, and reduced mobility. Studies suggest that instrumented insoles can be an effective tool for improving postural balance, particularly in individuals with balance impairments or age-related declines in balance. The mechanisms by which insoles improve balance are likely multifaceted and involve alterations in plantar pressure distribution, increased sensory input to the feet, and strengthening of the foot and ankle muscles. Instrumented insoles can alter plantar pressure distribution. Proper distribution of pressure across the foot is important for maintaining balance, as it helps to maintain stability and prevent falls. By altering the distribution of pressure across the foot, instrumented insoles can improve balance. Instrumented insoles can improve proprioception, which is important for balance because it allows the brain to know where the body is in space and how it is moving. Instrumented insoles can improve proprioception by providing feedback to the feet and improving the ability of the brain to detect changes in position and movement.
- Gait deviations – Instrumented insoles can correct gait deviations by providing real-time feedback about gait and balance, and by altering the distribution of plantar pressure during gait. These corrections can help to improve the quality of gait and reduce the risk of falls and injuries. Specifically, these devices can help individuals to avoid unwanted movements of the ankle such as excessive supination or pronation. If an individual has a tendency to roll their foot outward (supination), an instrumented insole can provide additional support to the lateral side of the foot, which can help to correct the supination and improve gait. Similarly, if an individual has a tendency to roll their foot inward (pronation), an instrumented insole can provide additional support to the medial side of the foot to correct the pronation and improve gait. As mentioned earlier, instrumented insoles are a great tool for improving proprioception. With the body in full motion, proprioception is very important as it allows the body to keep balance during the movement. Additionally, instrumented insoles can help to correct other gait deviations such as altered step length, toe walking, limping, foot drop. They also can play a role in correcting knee hyperextension, hip drop, and flat foot.
Overall, instrumented insoles are an effective way to help individuals suffering from postural and gait deviations. By correcting these variations, people can be alleviated from pain and discomfort. Instrumented insoles can be a versatile tool for correcting a variety of gait deviations, including those caused by muscle weakness, joint stiffness, or poor posture. By providing real-time feedback and additional support or stimulation, instrumented insoles can help individuals with gait impairments to improve their balance, mobility, and quality of life.