Ever wonder why, as people age or develop Parkinson’s disease, something as simple as standing up or turning can suddenly become a risky endeavor? It turns out that balance problems in these groups may not arise from a lack of effort or muscle weakness, but from the brain and muscles working too hard — a surprising reversal of what many might expect. Instead of a sluggish response, the body’s overactivity in both neural and muscular systems can actually sabotage stability, making falls and stumbles more likely. This counterintuitive finding is reshaping how scientists and clinicians understand — and hope to treat — balance impairment in aging and Parkinson’s disease.
Short answer: Overactivity in the brain and muscles during balance challenges in older adults and people with Parkinson’s disease leads to exaggerated, poorly coordinated responses that hinder, rather than help, balance recovery. This hyper-engagement increases muscle stiffness and requires more cognitive effort, ultimately making movements less efficient and raising fall risk, as confirmed by multiple recent studies.
Let’s unpack how and why this happens, and what it means for understanding — and potentially treating — balance problems in aging and Parkinson’s disease.
What Happens in Normal Balance Recovery?
In healthy young adults, balance recovery is remarkably automatic. When a person is suddenly destabilized — imagine the classic “pulling the rug out” experiment — the body responds with a rapid, involuntary sequence of muscle and brain activity. According to research highlighted by ScienceDaily, this initial wave is managed by the brainstem and quickly activates the right muscles to regain equilibrium. If the disturbance is more severe, a secondary, slightly delayed response involving higher brain centers kicks in to fine-tune the reaction.
This automaticity means that most of the time, we maintain balance without conscious thought or excessive muscle engagement. The muscles involved in stabilizing the body contract and relax in a coordinated, efficient manner, allowing for smooth corrections and minimal energy expenditure.
How Aging and Parkinson’s Change the Equation
However, the picture changes dramatically with aging and Parkinson’s disease. As detailed in ScienceDaily’s 2026 report, researchers found that both older adults and people with Parkinson’s display “stronger brain responses and increased muscle activity even during minor balance disruptions.” In other words, instead of a subtle, automatic adjustment, their brains and muscles overreact — pouring extra effort into what should be a simple correction.
This “overactive” response doesn’t just use more energy; it actively undermines stability. Lena Ting, a leading researcher cited by both ScienceDaily and news-medical.net, explains that greater engagement from the brain correlates with a less robust ability to actually recover balance. When more brain activity is required to stay upright, it’s a sign that the body’s balance systems are no longer functioning smoothly or efficiently.
Muscle Stiffness: When “Trying Harder” Backfires
One of the most striking findings from these studies is how muscle behavior changes with age and Parkinson’s. Normally, when one muscle contracts to stabilize the body, the opposing (“antagonist”) muscle relaxes, allowing a fluid movement. In older adults and those with Parkinson’s, however, both the stabilizing and opposing muscles may tense up at the same time. This phenomenon — known as co-contraction or muscle stiffening — creates unnecessary rigidity.
As described by news-medical.net, the degree of muscle stiffening is “linked to worse balance performance.” The body becomes less able to adjust quickly to sudden shifts, so movements become jerky and inefficient. This muscle rigidity is also a well-documented symptom in Parkinson’s disease, where it’s referred to as “cogwheel rigidity” (ninds.nih.gov), reflecting the characteristic ratcheting or stop-and-go quality of affected limb movements.
The Double Burden: Brain Overactivity and Loss of Automaticity
But why does this overactivity develop? One major factor is the loss of automatic control over movement that occurs with both aging and Parkinson’s. The basal ganglia — deep brain structures that help automate movements and suppress unwanted ones — become impaired in Parkinson’s due to the loss of dopamine-producing neurons in the substantia nigra (ninds.nih.gov, msdmanuals.com).
When the basal ganglia can no longer manage balance reflexively, the brain shifts the burden to higher, conscious regions, particularly the frontal cortex. The Parkinson’s Foundation (parkinson.org) notes that this “thinking part of the brain...can’t control balance automatically,” so balance corrections become slower, more attention-demanding, and less effective. This shift is measurable: Dr. Fay Horak’s team at the Parkinson’s Foundation used brain imaging to show that balance signals are “rewired” in people with Parkinson’s, forcing them to use more cognitive resources for what should be an unconscious action.
This increased cognitive load creates a phenomenon known as the “dual-task cost.” Simply put, when people with Parkinson’s try to walk and think at the same time, both tasks suffer — walking slows, and cognitive performance drops. This is not just a curiosity; it’s a key reason why distractions or multi-tasking can make falls more likely in these populations.
The Vicious Cycle of Overcompensation
This overactivity sets off a vicious cycle. When balance reflexes are weak, the brain and muscles compensate by “trying harder.” But this extra effort — more brain engagement, more muscle contraction — doesn’t produce smoother movement. Instead, it leads to greater stiffness and less agility, actually increasing the likelihood of losing balance. As ScienceDaily puts it, “trying harder may actually make you more likely to fall.”
This pattern is especially problematic during complex movements like turning or when encountering unexpected obstacles. The Parkinson’s Foundation highlights that turning, which requires a rapid, coordinated shift of balance, is particularly difficult for people with Parkinson’s. Their movements become segmented and slow, and they may take four or five steps to turn instead of one or two. People with more advanced Parkinson’s often avoid turning altogether, because it’s so likely to trigger freezing or falls.
Overactivity in the Context of Parkinson’s Disease
Parkinson’s disease brings additional complexity. Beyond the loss of dopamine in the basal ganglia, people with Parkinson’s also experience the formation of Lewy bodies — abnormal protein aggregates that disrupt cellular function (msdmanuals.com, ninds.nih.gov). The disease affects not only the brain’s movement circuits but also the autonomic nervous system, which controls automatic functions like blood pressure and heart rate.
Balance dysfunction in Parkinson’s, as detailed in a review from PMC (pmc.ncbi.nlm.nih.gov), arises from “a multilevel impairment” of postural control systems. This includes not only the primary motor symptoms — tremor, rigidity, bradykinesia (slowness), and postural instability — but also disruptions in sensory integration and automaticity. Subtle changes in posture can appear early in the disease, even before overt motor symptoms, and worsen as the disease progresses.
Importantly, the PMC review stresses that stability and mobility depend on “precise regulation of phasic and tonic muscular activity that is carried out automatically, without conscious awareness.” In Parkinson’s, the breakdown of this automatic regulation forces the person into a state of chronic overcompensation, making every movement more taxing and less reliable.
Real-World Consequences: Falls, Freezing, and Quality of Life
The practical impact of this overactivity is seen in the high rates of falls among older adults and those with Parkinson’s. According to the Parkinson’s Foundation, people with Parkinson’s are particularly prone to freezing — a sudden inability to move the feet forward — and to taking small, shuffling steps that further compromise stability. Falls are not only common but also potentially devastating, leading to injuries, loss of independence, and a decline in overall quality of life.
Moreover, as noted in ScienceDaily, “balance recovery takes more energy and engagement from the brain” in these populations, making everyday activities like walking, turning, or even standing up more mentally and physically exhausting. This increased effort can lead to fatigue, anxiety (which itself can worsen freezing), and a general reluctance to engage in physical activity, further weakening balance systems.
Hope on the Horizon: Identifying and Addressing Overactivity
The emerging understanding of overactivity’s role in balance dysfunction opens new avenues for both assessment and intervention. Researchers like Lena Ting suggest that by measuring muscle activity after a balance challenge, clinicians may be able to identify people at higher risk for falls before they occur (news-medical.net). This could allow for earlier, targeted interventions — such as balance training, exercise, and physical therapy — to retrain and optimize motor responses.
Exercise, in particular, is highlighted by the Parkinson’s Foundation as the only intervention proven to reduce fall risk in both older adults and people with Parkinson’s. Structured physical therapy can help teach individuals to take larger, more effective steps and to use external cues (like a metronome or visual markers) to bypass impaired automatic pathways.
Key Details and Contrasts from the Research
To illustrate how thoroughly this new understanding is grounded in scientific findings, here are concrete details and comparisons from the sources:
1. In both older adults and people with Parkinson’s, even “minor balance disruptions” can trigger “larger brain responses and more muscle signals” than in younger adults (news-medical.net, ScienceDaily). 2. The overactive response means that “when people require more brain activity to balance, they have less robust ability to recover their balance” — a paradoxical but well-documented effect (ScienceDaily). 3. Co-contraction of opposing muscles — both tensing up at once — leads to “added stiffness” and “poorer balance performance” (news-medical.net). 4. Parkinson’s disease involves the loss of “60 to 80% or more of the dopamine-producing cells in the substantia nigra by the time symptoms appear,” disrupting automatic movement control (ninds.nih.gov). 5. The basal ganglia, which “help initiate and smooth out muscle movements,” are particularly affected in Parkinson’s, shifting balance control from automatic to attention-demanding processes (msdmanuals.com, parkinson.org). 6. Turning is especially challenging: “people with PD turn significantly more slowly” and take “four or five steps to make a turn,” increasing fall risk (parkinson.org). 7. Overactivity is not just a symptom of Parkinson’s, but also a feature of normal aging, though it is more pronounced and disabling in Parkinson’s (ScienceDaily, news-medical.net).
Final Thoughts: A New Perspective on Balance
In summary, the revelation that overactivity — not underactivity — in the brain and muscles undermines balance in aging and Parkinson’s disease marks a significant shift in how scientists and doctors approach fall prevention. Rather than simply trying to boost strength or stimulate reflexes, the focus is moving toward restoring the smooth, automatic regulation of movement that healthy balance requires.
Understanding and addressing this overactivity could help millions of older adults and people with Parkinson’s regain confidence, reduce falls, and improve their quality of life. As research continues, interventions that retrain the brain and body to respond efficiently — rather than excessively — may prove the most promising path forward.