1.3 PT vs PTA Scope of Practice (Critical)

Why scope of practice is the single most testable concept

Almost every clinical scenario on the NPTE-PTA can be filtered through one question: Is this action inside or outside the PTA's scope? Answer that quickly and you eliminate distractors in nearly every case-based item, regardless of body system. The writers know scope is what protects the public, so it appears directly in Professional Responsibilities items and indirectly throughout body-system items. This is why scope mastery compounds: it raises your accuracy on far more than the 2-4 items that explicitly test it.

What a PTA CAN do

Under the supervision of a licensed PT, a PTA may:

• Carry out the established plan of care (POC) — deliver the interventions the PT documented.
• Implement and progress therapeutic exercise — strengthening, ROM, flexibility, endurance, neuromuscular re-education, and gait training within the POC.
• Apply therapeutic modalities — ultrasound, electrical stimulation, thermal agents, mechanical traction, hydrotherapy, within POC parameters.
• Perform data collection — re-measure ROM and MMT, take vital signs, observe gait, time the Timed Up and Go (TUG), and document against the PT's baseline.
• Apply joint mobilization grades I-IV (non-thrust) where the jurisdiction and setting permit and the PT delegates it.
• Provide patient and family education consistent with the POC.
• Adjust dose within the POC — change repetitions, sets, or modality time within the parameters the PT set.
• Recognize when to stop — hold an intervention if vital signs, pain, or function fall outside the PT's parameters, then notify the PT.

What a PTA CANNOT do

A PTA may never:

• Perform the initial examination or evaluation — this establishes the diagnosis and prognosis and is the PT's exclusive responsibility.
• Establish, write, or substantively modify the POC — a PTA may suggest changes, but only the PT may change the plan.
• Interpret tests and measures for diagnostic purposes — the PTA collects data; the PT interprets data that changes the diagnosis or POC.
• Perform sharp selective debridement with a scalpel, scissors, or other sharp instrument.
• Perform grade V joint mobilization (high-velocity, low-amplitude thrust) or spinal manipulation.
• Discharge the patient from physical therapy services.
• Bill or document under an evaluation code — PTAs document interventions and progress against the PT's plan, not a new evaluation.

Supervision tiers

Each jurisdiction defines exactly how a PT must supervise a PTA. Three tiers recur on the exam; read the stem for the PT's location.

If the stem says the PT is "off site by phone," you are in general supervision; "in the next room / on site," direct; "observing the treatment," direct personal.

The decision filter for any case-based item

When a scenario asks what the PTA should do, run this filter in order:

1. Is the patient safe right now? If not, address safety first (stop treatment, position safely, call for help).
2. Is the action a PT-only function? (evaluation, diagnosis, POC change, discharge, sharp debridement, grade V). If yes, the PTA notifies the PT.
3. Is the data point inside the POC parameters? If yes, continue; if outside, hold and notify the PT.
4. Does the action require a supervision level the setting lacks? If yes, wait or notify.

Most "What should the PTA do next?" items resolve to continue within the POC or notify the supervising PT. When two answers seem reasonable, notifying the PT is the safer, more defensible choice than acting independently.

Worked scenarios that show the filter in action

Scenario A — the tempting "helpful" answer. A home-health PTA under general supervision finds that a patient has clearly progressed and could be discharged. Two options say "discharge the patient" or "add a home program and discharge." Both are traps: discharge is a PT-only function. The defensible answer is to document the gains and notify the PT, who decides on discharge. The trap works because the action feels clinically correct — the exam is testing the boundary, not the clinical judgment.

Scenario B — data collection vs. interpretation. A PTA re-measures knee ROM and finds it improved 15 degrees. Recording the measurement and comparing it to the PT's baseline is within scope (data collection). But an option that has the PTA "revise the goals based on the new ROM" crosses into modifying the POC — PT-only. Re-measuring is fine; deciding what the measurement means for the plan is not.

Scenario C — supervision mismatch. A new PTA student is asked to perform a treatment while the supervising PT steps out of the building. If the setting requires direct or direct-personal supervision for the student, the correct action is to wait until appropriate supervision is present — not to proceed because the treatment itself is simple. The barrier here is the supervision tier, not the skill.

Quick-reference: PT-only red-flag verbs

When any of these verbs attach to the PTA in an answer choice, the option is almost always wrong:

Memorizing these verbs lets you eliminate distractors in seconds, even on body systems you find difficult — which is exactly why scope of practice is the highest-leverage topic in this chapter.