Can NDT Evolve? Or Is It Time for Neurodevelopmental Treatment to Bow Out?

Neurodevelopmental Treatment (NDT) has a long, storied history in neurorehabilitation, dating back to the 1940s. Originally rooted in the reflex-hierarchical model of motor control, NDT assumed that motor recovery in individuals with neurological impairments required “retraining” of primitive reflexes and “normalization” of tone through a top-down approach. According to the model, as primitive reflexes are gradually inhibited and tone is normalized, higher motor functions are “unlocked” in hierarchical order. However, as modern science progressed, so did our understanding of the brain, movement, and recovery, leading to new frameworks like the dynamic systems theory that emphasize task-specific, context-driven recovery.

Yet, as evidence continues to mount against the effectiveness of NDT, a curious trend has emerged among its proponents: instead of directly addressing the theory's shaky foundations, they’ve started to insist that NDT has “evolved.” They claim it’s no longer about reflexes and hierarchies—it’s now task-oriented, adaptable, and in harmony with dynamic systems theory. But can an approach simply say it’s evolving when its fundamental assumptions have been discredited? Or is it attempting to change its stripes simply because the evidence is unsupportive?

The “Evolution” Argument: Is It Genuine Progress or Just Moving Goalposts?

One challenge with “evolving” approaches like NDT is that when the central assumptions of a treatment paradigm are overturned, its proponents are often left scrambling. They pivot, suggesting that the method has “adapted” to new evidence, and claim NDT now includes modern principles like task-oriented practice and dynamic systems theory. This mirrors the type of argument commonly seen when religious or ideological beliefs come under scientific scrutiny.

Upon encountering contradictions, there’s a shift to say, “Oh, we’re not actually stuck in the old ways; we’re evolving.” But can we take this at face value?

In science, a theory can only evolve within the constraints of its foundational assumptions. Once scientific understanding moves beyond these boundaries, the framework itself must be replaced. Reflex-hierarchical theory, the underpinning of NDT, has been shown inadequate in explaining motor recovery following neurological injury, and models that succeeded it—such as task-oriented and dynamic systems-based approaches—offer more precise and functional insights.

Furthermore, NDT, as a clinical method, is not a theory but rather an application of outdated concepts, bolstered by clinical observations that frequently lack rigorous scientific validation. While some NDT techniques may retain intuitive appeal, they are not substantiated by strong evidence, making it increasingly difficult to endorse NDT as a primary approach in contemporary neurorehabilitation. As a result, NDT's claim to "evolution" is not only unsupported but misses the critical scientific shift toward evidence-based, functionally oriented interventions.

When proponents claim NDT is “evolving,” they may not mean that it is becoming more valid but rather that elements of it are being adapted to fit newer practices and evidences.

This raises the question: If the theoretical foundation is flawed, does keeping certain techniques truly constitute evolution, or is it just repackaging outdated ideas?

Testing NDT in the Era of Evidence-Based Practice

Proponents of NDT are often quick to dismiss RCTs that show little to no benefit of NDT compared to task-oriented training. When confronted with studies that suggest NDT’s limited efficacy, they argue that RCTs are not appropriate for testing complex, individualized treatments like NDT. Instead, they argue that therapy “nuances” such as therapist skill, individual client needs, and the “art” of clinical judgment make it impossible for RCTs to capture the approach’s true effectiveness.

However, this line of reasoning is flawed. Numerous treatments across healthcare, including complex psychological therapies like cognitive-behavioral therapy (CBT) and other multi-faceted behavioral interventions, have been tested rigorously through RCTs. The individualized nature of these treatments has not precluded their assessment in controlled settings. Why, then, is NDT supposedly so special? There’s a risk here that proponents are attempting to shield NDT from scrutiny, asserting that it’s simply “too complex” to be evaluated by conventional scientific standards. This argument, while convenient, is at odds with a commitment to evidence-based practice.

NDT’s Future: Can It Evolve, or Must It Die?

In light of these points, we arrive at a pivotal question: can NDT truly evolve, or must it be set aside? While it’s possible for any method to adapt, a shift that merely repackages outdated theories as “new” does not constitute genuine progress.

In the same way that Rood’s sensory stimulation techniques and Brunnstrom’s recovery stage based approaches were supplanted by more effective, task-oriented approaches, Neurodevelopmental Treatment (NDT) has reached a point where evolution is no longer a viable option; it requires replacement.

Science advances not by continuously reshaping outdated models to fit new data but by adopting theories that better explain and predict outcomes, as Thomas Kuhn’s paradigm shift concept reminds us.

There is often resistance within clinical communities to abandon methods like NDT, given the investment in training and clinical practice over decades. However, clinging to NDT under the pretense of "evolution" risks slowing the adoption of more effective, evidence-based approaches.

As it stands, calling NDT an “evolving” approach feels like a linguistic maneuver rather than a genuine shift. A method whose foundations are disproven cannot simply adapt and reappear unchanged; it must either reform completely with new evidence or be put to rest. Let’s reserve neurorehabilitation’s valuable time, resources, and trust for methods that stand up to scrutiny rather than those relying on a plea for faith.

Perhaps it’s time to allow NDT the dignity of retirement and embrace treatments with both scientific integrity and practical efficacy.