What Is Proprioception?
Proprioception, also known as kinesthesia, is the sense that allows us to perceive the location and movement of parts of our body. Proprioception encompasses an array of sensory information, including muscle force, effort, joint position, and movement. This sensory information arises in proprioceptors, mechanosensory neurons in our muscles, skin, tendons, and joints. There is also a growing body of research that suggests many proprioceptors are in our myofascial tissue, which is the web of connective tissue that permeates all areas of our body, from head to toe and from surface to depth. Proprioceptors are everywhere, affirming their vital role in our ability to move freely and easily.
Proprioception and Walking
Properly functioning proprioception constitutes a continuous feedback loop between our proprioceptors and nervous system. Proprioceptors receive information and relay it to our nervous system, and our body responds accordingly. Most often, we are unaware of this ongoing feedback loop, which is good! Without proprioception, we would be unable to move without consciously thinking about and planning our next action.
Proprioception is why we can touch our nose with our eyes closed or pick up a glass of water on the table with appropriate effort. It is also the reason we can walk without thinking about the next step. Without proprioception, we would need to watch, consciously plan, and then modulate the placement of our feet, the length of our stride, the actions of our legs, the amount of muscular force needed, and the coordination of our steps. It would be very difficult to get from point A to B!
These are some specific ways our walking health is impacted by proprioception.
What is Automaticity?
Automaticity is a key feature of healthy, well-functioning walking in adults. It refers to the ability of our nervous system (in combination with other systems including our visual and vestibular systems) to control typical steady walking with minimal executive control. In other words, it is the ability to walk without devoting much (or any) attention to planning and managing each step. In walking, proprioceptors provide input to the central nervous system (which includes our brain and spinal cord) regarding limb position and weight bearing, both of which are central to automaticity. When proprioception is impaired, a walker must attend to these components of their walking consciously, which studies have shown is not an efficient or effective method of controlling movement.
Why is Foot Placement Important When Walking?
It doesn’t only matter how you step—it also matters where you step. Proprioception is central to this process, too, helping us to correctly place our feet in walking. More specifically, proprioceptors at the hip appear to be instrumental in controlling correct placement of our feet in walking—what’s known as a mediolateral location. This placement not only ensures stability in walking, but it is also central to maintaining proper alignment as well as ensuring efficient recruitment of muscles in walking.
Smoothness and Efficiency in Walking
To walk smoothly and efficiently across variable surfaces, our body needs to be able to sense and respond to the ground underfoot. Research suggests that proprioception is central to our ability to maintain a smooth, efficient gait even as the ground shifts and changes. Proprioception is the reason we can correct stumbles before they turn into falls and the reason we can manage unexpected changes in terrain.
Balance in Walking
Interestingly, our vestibular system, largely responsible for our sense of balance, may take a passenger seat when we walk. During walking, it appears that vestibular information is actually less important than proprioception, which dominates muscle activity. In fact, reduced proprioceptive abilities at the ankle joint in older adults may significantly contribute to fear of falling. Some studies even conclude that assessing proprioception could be fundamental to assessing fall risks in older populations.
Gait Speed and Stride Length
Proprioception is also a key component to gait speed and stride length—how quickly we walk and how big or small our steps are. Similar to the studies investigating the links between proprioception and balance, current research suggests that proprioception at the ankle joint is a significant factor in both gait speed and stride length.
Causes of Impaired Proprioception
Proprioception can be affected by a range of things, including age, substances like alcohol, injuries, and other medical conditions. For example, as we age, our nerves, joints, and muscles change, just like the rest of our body, which can impact proprioception. Injuries and medical conditions can also cause impaired proprioception, either temporarily or permanently. For example, a herniated disc or sprained ankle may temporarily impede your ability to sense your body parts and their actions. Diseases like Parkinson’s and Lou Gehrig’s disease can permanently compromise proprioception.
How to Improve Proprioception
Just like developing muscular strength, flexibility, or joint range of motion at the gym, proprioception can be trained and improved. Balance exercises, activities like the moving meditation practice of Tai Chi, and joint repositioning training are just some ways you can improve proprioception and support your walking health.
Consider how often you walk. Even if you’re still working on upping your daily step count, chances are walking is how you most often get from point A to B—from your desk to the conference room, from your car to the coffee shop, from your kitchen to living room. Throughout each of these journeys, you have a steadfast, hardworking companion: proprioception. Thanks to this amazing neurophysiological ability, we never walk alone.