3.6 Balance, Coordination, & Vestibular Basics

Why Balance Measures Matter

Balance depends on the integration of three systems — visual, vestibular, and somatosensory (proprioceptive) — processed centrally with help from the cerebellum and brainstem. When one system fails, the others compensate; the exam often tests which system is being challenged or removed by a given task. PTAs deliver large volumes of balance and fall-prevention training, and the NPTE-PTA expects you to know the standardized measures, their cutoff scores, and exactly where PTA scope ends in vestibular care.

Standardized Balance Outcome Measures

Berg Balance Scale (BBS)

The Berg Balance Scale (BBS) rates 14 functional tasks (sitting, standing, transfers, reaching, turning, retrieving an object, single-leg stance) on a 0-4 scale, for a maximum of 56 points. Higher is better.

• A score of 45 or below is commonly used as a marker of increased fall risk (some literature uses cutoffs up to 51, but 45/56 is the classic exam answer).
• The BBS tracks progress across a plan of care; the PTA can administer it as a data-collection task when the PT includes it.

Timed Up and Go (TUG)

The Timed Up and Go (TUG) test times the patient as they stand from a chair, walk 3 meters, turn, walk back, and sit down.

• A time greater than roughly 13.5 seconds in community-dwelling older adults is commonly associated with elevated fall risk; times of about 30 seconds or more suggest dependence in mobility.
• The TUG is quick, requires minimal equipment, and is a strong PTA progress-tracking tool.

Other Common Measures

Romberg and Sharpened Romberg

The Romberg test isolates the proprioceptive (somatosensory) contribution to standing balance. The patient stands with feet together:

• Eyes open: vision, vestibular, and proprioception all contribute, so the patient is steady.
• Eyes closed: vision is removed, so the patient must rely on proprioception and the vestibular system.
• A positive Romberg sign — steady with eyes open but significant sway or loss of balance with eyes closed — suggests a proprioceptive (sensory) deficit, such as peripheral neuropathy or posterior-column disease. (A patient unsteady even with eyes open points toward a cerebellar or vestibular problem instead.)

The sharpened (tandem) Romberg narrows the base of support by placing one foot directly in front of the other, increasing the challenge for higher-functioning patients.

Coordination Screening

Coordination tests help identify cerebellar dysfunction. Common screens a PTA may observe or assist with:

• Finger-to-nose and finger-to-therapist's finger — test for dysmetria (over- or undershooting a target).
• Heel-to-shin — lower-extremity coordination.
• Rapid alternating movements (forearm pronation/supination) — impaired performance is dysdiadochokinesia.
• Observe for intention tremor (worsens approaching a target), ataxic gait (wide-based, unsteady, irregular), and nystagmus.

Cerebellar signs are often summarized by the mnemonic DANISH: Dysmetria, Ataxia, Nystagmus, Intention tremor, Slurred/scanning Speech, Hypotonia/dysdiadochokinesia.

Vestibular Rehabilitation Basics and PTA Scope

Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo, produced by displaced otoconia (calcium carbonate crystals) in a semicircular canal — most often the posterior canal. It is identified with positional tests such as the Dix-Hallpike and treated with canalith repositioning maneuvers such as the Epley maneuver.

Scope boundary — high-yield for the NPTE-PTA: the diagnostic positional testing and the canalith repositioning maneuvers are performed by the physical therapist, who evaluates the patient and establishes the plan of care. Within that plan of care, the PTA implements:

• Habituation exercises — repeated, controlled exposure to provoking movements (for example, Brandt-Daroff exercises) to reduce the symptom response over time.
• Gaze-stabilization exercises — vestibular-ocular reflex (VOR) training, such as maintaining visual focus on a target during head movement.
• Balance and gait training, postural strategies (ankle, hip, and stepping strategies), and fall-prevention activities.

If a patient develops new or worsening vertigo, new neurological symptoms, or unexpected responses, the PTA stops the activity and reports to the supervising PT rather than performing or modifying a repositioning maneuver. That scope line is one of the most reliably tested points in this section.

Sensory-System Reasoning and Fall-Prevention Progressions

Because balance pools visual, vestibular, and somatosensory input, the exam often describes a task that removes or challenges one channel and asks what is being trained. Standing on foam degrades somatosensory input and forces reliance on vision and the vestibular system; standing with eyes closed removes vision; combining foam plus eyes closed isolates the vestibular system — the basis of the modified Clinical Test of Sensory Interaction on Balance (mCTSIB).

The PTA grades difficulty by manipulating these conditions: firm-to-foam surface, eyes-open-to-closed, wide-to-narrow base, and static-to-dynamic tasks such as head turns or reaching.

Fall-prevention progressions move from static standing balance, to dynamic weight-shifting and reaching, to anticipatory tasks (stepping over objects, catching), to reactive balance (controlled perturbations and protective stepping), and finally to dual-task training that adds a cognitive demand while walking. Throughout, the PTA guards with a gait belt, controls the environment, and documents objective measures (BBS points, TUG seconds, number of losses of balance).

A worsening score, a near-fall, or new vertigo prompts a report to the supervising PT rather than an independent change in the plan of care, keeping the PTA squarely within scope while still advancing the patient's safety and function.