Physical therapy may not be a souped-up DeLorean, a table-top machine, or a twistable pendant that takes its users backward in time, but unlike the fictional Doc Brown, Time Traveler, or Hermione Granger, physical therapists can use real-life tools to at least slow it down.

Richard Shields, PT, PhD, FAPTA, in his delivery of the 48th Mary McMillan Lecture on June 22, said that as physical therapists "we change time. We routinely turn over the hourglass" and through interventions "reset the aging clock of the human body."

Discussing the future of the physical therapy profession at "micro" and "macro" levels, Shields said that for much of the profession's history PTs have remained in the center of this continuum. "But the frontiers of our profession lie at the extremes. Those are the places we must travel if we wish to truly transform society by optimizing movement," he said, alluding to APTA's vision for the profession—"Transforming society by optimizing movement to improve the human experience."

On the micro level, Shields said that physical therapist interventions "are powerful regulators of genes that activate the energy systems" that can reduce the rate at which cells and tissues age. These movement-based interventions trigger cellular changes "in ways that the pharmaceutical industry"—if not Doc and Hermione—"can only dream about."

Shields explained how, upon contraction, skeletal muscle is more than "a mere force vector." It also releases proteins known as myokines into the blood stream, where they regulate genes in cells throughout the body.

Frequent movement, then, promotes the expression of healthy genes and represses the expression of genes that can damage tissues. And while the effect is to slow biological aging in cells and tissue, the benefits are not for only the already aged; they can be applied across the lifespan. Shields said that although PTs and PTAs "most often think about strength, endurance, coordination, and function; the cellular changes that we trigger are the most fundamental ways that we improve the health and well-being of humankind."

Shields explained that it's possible to estimate how many healthy genes are being blocked as a function of a person's age, injury, immobility, or disease. "It is our role as physical therapists to prescribe interventions that unblock the genes that are health-promoting," Shields said.

Further, he said, repeated movement creates a "molecular memory" that perpetuates the healthy genes' activity. Physical therapy, with its emphasis on continued movement and activity, is a catalyst for this molecular memory.

Given current knowledge about the human genome, coupled with ever-improving methods of individual data collection, doses of movement can be customized for each patient, based on biological genetic regulators, environmental factors, and lifestyle influences that affect frequency, duration, and types of treatment prescribed. As a result, Shields predicted that "precision physical therapy will emerge side-by-side with precision medicine."

Turning to the macro level of physical therapist practice—the impact on the human experience—Shields warned against treatments that are "more about the therapist or the technology owned by an institution than about the experience of the patient." He continued that using new attention-grabbing treatments that often involve technology may be at the cost of teaching the patient a needed skill for continued long-term mobility, "even something as simple as [manually] wheeling a chair" instead of using a motorized one.

Using an airline flight for illustration, Shields explained how a patient's experience is affected by nuances of expectation. He asked: "How many of you wished you arrived in Boston 45 minutes early? How many expected to arrive on time? How many would have viewed the flight as a success if you arrived safely, even if delayed for a few hours? How many would have deemed the flight a failure if you had been carried off the plane because they needed your seat?"

There is a difference, he said, between what you wish for, what you expect, and what you would view as either a successful or failed experience. He said patient satisfaction should be viewed and measured from all 3 tiers of expectation, with a standard tool (he suggested an "Experience Efficiency Index") with the goal of reducing the number of unmet patient expectations.

"The idea of a central outcome measure about patient experience … is new but necessary, as growth can create silos that emphasize differences rather than commonalities," he said.