By Michael Kasimier, PT, DPT –
Miranda sat and watched the sun sink low into the western sky from the boardwalk overlooking her favorite stretch of beach. The late afternoon sun reflected off the textured gulf waters, creating a thousand tiny twinkling stars across the sea. Sunset was her time, time to thoughtfully reflect on events of the day, and plan for what was to come. It was a tradition she cherished. She hated to go a day without it.
Miranda’s eyes wandered from the sunset, over across the white sugar sand and shell beach, to the coconut palm positioned only a few paces from the high tide line. This particular palm grew nearer to the water’s edge than the other shoreline flora, with sand surrounding the entire trunk perimeter. This was Miranda’s palm. She had unofficially adopted it long ago, after many private trips across the loose packed sand, to sit against its trunk and watch the sun slide low while the soft salt breeze wafted over her. The tree itself was nothing special, but Miranda treasured it. For her the tree symbolized a ritual of lengthy duration, one that cleansed and recharged her spirit.
Signs of a Balance Problem
Now in the middle years of her seventh decade, Miranda felt she had mostly done the right thing to maintain good health. She ate well, exercised regularly, and indulged in few vices throughout her life. And it showed. Compared with her peers, Miranda remained in superb physical condition. So when her condition began to deteriorate, she had difficulty accepting the change. At first, the signs were subtle; a mild stumble as she turned her head while walking in the grocery to evaluate the status of the mangos displayed on the rack, a couple staggering nudges of the hallway wall while walking to the bathroom at night, a fleeting yet disconcerting sensation of imbalance when pulling her shirt on over her head. But as time passed, the subtle signs became more apparent. Soon Miranda had to acknowledge what she had not wanted to admit: she had a balance problem.
Unfortunately, Miranda’s situation is not an unfamiliar one to the older individual. Staying balanced is the result of a complex interaction of various body systems that act together to help us stay on our feet when standing and walking, as well as any activity that requires us to remain upright. Even with healthy aging, the functioning of the body systems that contribute to balance can weaken, placing the individual at a greater risk for falls and, in turn, injury and disability. Fortunately, many of these systems can be improved with the appropriate treatment, even in the older adult.
Four Body Systems Contribute to Maintaining Balance
Broadly, four separate body systems contribute to maintaining balance while standing and walking. They include sensory input from your feet, the strength in your legs, your vision and input from your vestibular system (your inner ear). Input from these four systems is simultaneously and continuously sent to the brain in situations where balance is required, all of which must work together for us to maintain balance. Certain pathologies, as well as natural aging, can compromise the effectiveness of these systems.
Feet and Ankles
The first body system that contributes to balance is the sensory input from your feet and your ankles, termed somatosensation, or proprioception. This is information sent to your brain from your feet and ankles telling your brain where your feet and legs are in space, and what type of surface you are walking on, without having to look down at your feet. When somatosensory input is reduced, staying balanced while standing and walking becomes difficult, particularly over compliant or soft surfaces, such as grass and soft carpeting. The softer the surface, the more “confused” the sensory input becomes. One reason Miranda opts to remain on the boardwalk to watch the sunset instead of seeking refuge beneath her palm is because she does not feel confident walking over the soft sand.
A common pathological condition that affects somatosensory input is peripheral neuropathy. Peripheral neuropathy is a disease that damages the peripheral nerves, primarily of the feet and hands, potentially resulting in decreased sensation, reduced foot muscle function, and pain. When sensation is reduced, balance becomes compromised. Traditionally, peripheral neuropathy treatment consisted of pain medication to manage symptoms. More recently, treatment approaches involving a mild local nerve block to the nerves of the lower extremities combined with electrical stimulation to the legs and feet have shown positive results in reduction of pain, increasing sensation, and enhancing balance in individuals suffering from peripheral neuropathy.
Leg Strength
The second body system that contributes to balance is leg strength, particularly of the ankle, hip, and thigh musculature. We utilize certain strategies to maintain balance when our center of gravity moves outside our base of support (the area between our feet); ankle, hip, and stepping strategies. Our first line of defense to falling is the use of the ankle strategy. When encountered with a relatively small force that threatens to knock us off kilter, the muscles of our feet and ankles work to keep us steady. When a larger force interrupts our balance, we then use protruding hip motions, or a hip strategy, to keep our displaced center of gravity over our base of support. Adequate muscle strength of the muscles surrounding the ankles, hips, and knees are important to optimize these strategies for safe performance of daily activities and walking.
Vision
The third body system employed for balance is vision. Adequate vision is important to see objects in your path while walking, detect a change in the regularity of the surface you are walking on, as well as negotiate curbs and stairs. Conditions such as cataracts, macular degeneration, and glaucoma can alter our vision, leaving us more reliant on our other systems for balance and increasing risk for falls. One of Miranda’s complaints is that she has a difficult time keeping her balance after the sun goes down, when her world becomes a little darker. Also, she experiences difficulty when walking in the hallway at night, as well as pulling on her shirt over her head. Both of these activities decrease visual input. Evaluation of Miranda’s visual acuity may be in order to rule out vision impairment as a contributor to poor balance.
Vestibular System (Inner Ear)
The fourth and final major system that contributes to balance is the vestibular system, commonly referred to as the inner ear. The vestibular system located on either side of the head, just behind and adjacent to the structures of the ear. This system provides information to the brain regarding spatial orientation, position of the head in relation to the body, as well as in relation to upright posture. Several pathologies can affect the vestibular system, including Benign paroxysmal positional vertigo, Meniere’s disease, acoustic neuroma, perilymphatic fistula, among others. Pathological vestibular dysfunction is most often accompanied by vertigo, or a sensation of spinning while remaining still. Tinnitus, or ringing in the ear, as well as nausea, can accompany vestibular pathology.
The vestibular system can also be affected by natural aging. By the age of 70, we have lost around 40 percent of the receptor cells of the vestibular system. Age related vestibular hypofunctioning can lead to an increased risk for falls. This is particularly evident in situations when vision is reduced, such as pulling on a shirt overhead or closing your eyes when washing your hair in the shower. This type of vestibular dysfunction is not typically accompanied by classic vertigo symptoms.
Miranda has trouble walking over soft and uneven surfaces, as well as ambulating in darker environments. In situations where vision and sensation are compromised, increased reliance on the vestibular system is utilized for balance. If the vestibular function is also compromised, adequate balance becomes very difficult to achieve. Miranda may benefit from further vestibular function assessment, as well as a course of physical therapy for vestibular rehabilitation.
Balance Therapy with a Physical Therapist Can Help
As Miranda has discovered, impairment in walking and standing balance can lead to a significant reduction in mobility and independence, safety, increased incidence of debilitating injury, and a decreased quality of life. In some instances, balance issues can be alleviated with something as simple as a medication change, or even a few head movements to address positional vertigo symptoms. More often, however, the cause of balance impairment is multifactorial and frequently requires a comprehensive treatment approach. Most often this includes consultation with a physician, who may refer you to a specialist if necessary. In addition, a referral to a physical therapist may be warranted for a patient-specific balance therapy program.
Miranda returned to the same beach later that same month, again near sunset. She moved to the edge of the boardwalk, glanced over to her tree, and then back down to the sand. The thought of walking across the uneven sandy beach, in this dim light, was still a daunting proposition. Still, Miranda was encouraged. Even a little excited. Earlier that day she had paid a visit to her physician and confessed to her the difficulties she had been experiencing with her balance. Together they had formulated a plan, and Miranda felt confident her balance would improve. Soon she would be watching the sunset from the sand, under her palm, where she belonged.
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