The Hidden Cost of Subjective Mobility Assessment in Healthcare
Mobility is a key measure of functional independence and quality of life in older adults. Despite its importance, mobility assessment in clinical practice is still largely subjective. Gait, strength, and balance are routinely evaluated through the lens of a clinician’s eyes or a quick paper-based questionnaire, leaving ample room for human error, variability, and missed warning signs.
This reliance on subjective evaluation is silently but profoundly shaping the health outcomes of millions of older adults. It is one of the key reasons we’re catching physical decline only after the fall.. In this article, we’ll explore how subjective mobility assessment became the norm, why it’s no longer sufficient, and how biomechanics is poised to fundamentally rewrite the way we evaluate, understand, and protect mobility as we age.
The Problem: Mobility Assessment Is Subjective by Design
In clinical settings, mobility is often assessed through standardized yet simplistic tools: the Timed Up and Go (TUG), the 30-Second Chair Stand Test, the Berg Balance Scale, or even just visual observation during a visit. While these tools have value, they rely heavily on the clinician's interpretation and the patient’s performance on a single day. The result is a snapshot, not a true picture.
Consider this common scenario: An older adult comes in for an annual visit. The provider watches them walk a few steps or do a sit-to-stand test and checks a box: “Independent ambulation, no assistive device.” End of evaluation.
What’s missing? Just about everything that matters.
Subtle changes in gait mechanics. Decreased force production. Narrowing base of support. Decline in power, cadence, or single-limb stance time. These are not easily seen with the naked eye and they’re often the first signs of physical decline. But because we don’t measure them, we don’t catch them.
The Impact: Late Detection = Poorer Outcomes
Falls are the leading cause of fatal and non-fatal injuries in older adults. One in four Americans aged 65+ falls each year, and the aftermath is often catastrophic. A fractured hip doesn’t just mean surgery. It means loss of independence, increased risk of institutionalization, and even premature death.
Many of these falls could have been predicted and prevented if we had better tools to measure risk.
Subjective mobility assessments often fail to detect early-stage decline. By the time a clinician notices weaker legs or unsteadiness, the person may already be on the brink of a fall. What we call the “first fall” is really the final sign of a long-simmering physical decline.
Worse still, subjective assessment can lead to under-treatment or over-treatment. A patient may be classified as “doing fine” and discharged from therapy too early or be labeled as high-risk based on age alone and referred for unnecessary interventions. Both scenarios cost the healthcare system and the patient.
How Did We Get Here?
Historically, healthcare has prioritized treatment over prevention. The tools we use today evolved in an era when measuring movement in detail simply wasn’t possible. Paper forms and time-based tests were the best we had.
Plus, many healthcare systems lack the resources or training to implement objective movement assessments. Time constraints, lack of technology, and the sheer volume of patients mean that most providers are forced to rely on “quick checks” rather than comprehensive analysis.
Physical therapists are highly trained in movement analysis, but even they are often limited by what tools are available in their setting. In a busy SNF or outpatient clinic, there’s rarely time or equipment for detailed gait analysis, let alone access to biomechanical data.
The Data Gap: What We’re Missing
Imagine if cardiovascular health were managed without blood pressure cuffs or EKGs. That’s essentially what we’re doing with mobility.
The body generates an enormous amount of biomechanical data during movement from gait speed, joint angles, step length, ground reaction forces, balance asymmetries, and much more. These data points show whether a person’s movement is improving or deteriorating, whether they’re compensating, whether they’re at risk.
But because we don’t collect that data, we’re blind to the earliest signs of trouble. It’s like trying to manage diabetes without ever measuring blood sugar.
The Consequences: Health, Cost, and Independence
The consequences of relying on subjective mobility assessment ripple far beyond the individual. At a population level, the healthcare system faces staggering costs due to preventable falls and hospitalizations. According to the CDC, falls among older adults cost the U.S. healthcare system over $50 billion each year. These numbers are expected to rise as the population ages.
More importantly, subjective assessment robs older adults of the opportunity to intervene early. With better detection, someone showing early signs of decline could begin targeted strength training, gait retraining, or environmental modifications far before a fall ever occurs.
We don’t wait until someone has a heart attack to treat their blood pressure. So why are we waiting for the fall to treat mobility?
The Future: Biomechanics and the Rise of Objective Movement Assessment
Biomechanics, the study of the mechanical laws relating to the movement of living organisms, offers a solution.
New technologies now make it possible to precisely measure human movement in clinical settings, without the need for expensive gait labs or wearable sensors. Force plates, motion capture cameras, and AI-powered video analysis can now provide accurate, quantitative movement data in minutes.
With these tools, we can track:
Gait speed and cadence
Area of base of support
Force symmetry index
Joint kinematics
Center of pressure displacement
These measurements are objective. They don’t rely on a therapist’s eye or a stopwatch. They create a digital fingerprint of movement, allowing clinicians to detect even minor changes over time.
More importantly, they enable early detection. A 10% drop in relative peak power or stride length might not be visible to a clinician but it may signal the beginning of decline. Catching it early means we can intervene early.
A Paradigm Shift: From Reaction to Prediction
Objective mobility assessment is more than just better measurement. It represents a paradigm shift in how we approach aging.
Instead of reacting to problems and waiting for someone to fall, decline, or fracture, we can predict them. We can shift from “sick care” to true health care.
Biomechanics makes movement measurable, trackable, and improvable. With regular testing, we can identify trends, set baselines, and monitor progress. We can build a preventive care model around mobility just as we already do with blood pressure, cholesterol, and bloodwork.
Challenges and Opportunities
Of course, integrating biomechanics into mainstream healthcare isn’t without challenges. It requires:
Investment in technology and training
Changes in clinical workflow
Reimbursement models that support prevention
Clear clinical guidelines for interpreting and acting on biomechanical data
But the opportunity is massive. By embedding objective mobility assessment into primary care, physical therapy, and senior wellness programs, we can:
Prevent falls and hospitalizations
Extend healthspan and independence
Reduce healthcare costs Empower older adults with data about their own bodies
It’s not about replacing clinicians. It’s about augmenting their expertise with tools that enhance precision and insight.
What Needs to Change
To move forward, healthcare systems and clinicians must recognize that traditional mobility assessments, while convenient, are no longer enough.
We must:
Adopt technology that captures real movement data
Train clinicians to interpret and apply biomechanical insights
Shift reimbursement and care models toward prevention
Educate patients that mobility is measurable and modifiable
Design systems that make mobility screening as routine as blood pressure checks
These aren’t distant ideals. They are possible today.
