Push and Release Test

Abstract

The Push and Release Test (P&R Test) is a concise, single-item clinical assessment designed to evaluate an individual’s reactive balance and automatic postural adjustments in response to an unexpected perturbation. The test involves the patient leaning backward against a therapist who then suddenly removes the supporting contact. The primary measure is the patient’s subsequent response (e.g., stepping, swaying, or falling) required to regain equilibrium. The reaction is scored using a 5-point ordinal scale, where a score of “0” signifies a normal, immediate, and effective recovery response. The P&R Test is commonly utilized in populations exhibiting postural control deficits, particularly those related to neurological conditions such as Parkinson’s disease.

Keywords

Push and Release Test, P&R Test, reactive balance, postural instability, automatic postural adjustments, performance measure, Parkinson’s disease, mobility assessment.

Authors

Horak FB (2004), KNGF-richtlijn Ziekte van Parkinson (2016) [Dutch Version Adaptation]

Purpose

The primary purpose of the Push and Release Test is to rapidly screen for and quantify deficits in reactive postural stability. Unlike measures that assess steady-state balance, the P&R Test focuses specifically on the integrity of the automatic motor programs necessary for recovering from sudden, unexpected shifts in the center of gravity (COG). It provides clinicians with a standardized, objective measure of the patient’s ability to initiate and execute appropriate protective strategies, such as stepping or grasping, when their stability limits are challenged.

The test is particularly valuable in clinical settings where time efficiency is critical, offering a quick alternative or supplement to multi-item balance scales. Its results help guide treatment planning, especially in rehabilitation programs targeting fall prevention and improved dynamic stability for conditions affecting the central nervous system.

Construct

The Push and Release Test measures the construct of Reactive Postural Control. This construct encompasses the automatic motor responses that occur following an external perturbation to restore the body’s equilibrium. Specifically, the P&R Test assesses the efficiency of the patient’s backward perturbation response—the ability to generate sufficient anterior torque at the ankle, hip, or trunk, or to execute a rapid stepping strategy to prevent a fall.

The scoring system reflects the severity of the deficit, ranging from a normal, single-step or non-step recovery (Score 0) to a complete inability to recover, resulting in a fall (Score 4). The test differentiates between patients who rely on compensatory strategies (e.g., multiple steps or excessive arm movements) and those who exhibit intact, automatic postural adjustments, which are often compromised early in progressive neurological disorders.

Validity

While the original source provides limited psychometric data, the P&R Test, often viewed as a refined version of the traditional pull test, demonstrates strong clinical validity. Studies have shown its concurrent validity through significant correlation with established gait and balance scales, including the Berg Balance Scale and the Timed Up and Go (TUG) test. The test is considered a sensitive indicator of postural instability, particularly in the context of Parkinson’s disease (PD), where axial symptoms are prominent.

The test’s construct validity is supported by its direct assessment of the motor response to perturbation, aligning with theoretical models of postural control. Its predictive validity is also high, as poor performance on the P&R Test is often correlated with an increased risk of future falls in elderly and neurological populations. The clinical utility of the test often outweighs the need for complex statistical validation due to its straightforward application and clear clinical interpretation.

Reliability

The reliability of the Push and Release Test is generally reported as moderate to high, particularly concerning inter-rater reliability, provided that clear standardization protocols are followed for administering the perturbation. Because the test involves a physical interaction between the patient and the examiner, consistent force application and timing are crucial for repeatable results.

Specific studies evaluating the P&R Test, especially when used in populations with PD, have reported good agreement among independent raters. This suggests that the 5-point ordinal scale provides sufficiently distinct categories for different levels of postural response, making it a reliable tool for tracking changes in reactive balance over time or across different clinicians.

Factor Analysis

As the Push and Release Test is a unidimensional, single-item performance measure, traditional methods of factor analysis are not applicable for determining internal structure. However, when included within a larger battery of gait and balance assessments, the P&R score typically loads onto a primary factor representing Postural Stability and Fall Risk. This demonstrates that the test effectively captures a key component of functional mobility distinct from factors related to strength or endurance.

Instrument

Test Type: Performance Measure (Objective clinical assessment)

Format: Single-item test scored using a 5-point ordinal scale.

Language Available: Original concept used globally; Dutch version standardized by the KNGF (Koninklijk Nederlands Genootschap voor Fysiotherapie) for the Parkinson’s disease guideline.

Population Group: Clinical and Geriatric populations.

Age Group: Adults, Elderly.

Population Details: Primarily used in individuals with neurological disorders (e.g., Parkinson’s disease, multiple sclerosis) and in older adults experiencing mobility issues or a high risk of falling. The test focuses on deficits in the lower extremity and nervous system functions related to movement.

Test Methodology: The patient stands comfortably, leaning backward against the therapist’s hands placed on the scapulae. The therapist stabilizes the patient’s heels to ensure proper stance. The therapist, without warning, removes the support (the “release”), causing the patient to lose balance backward. The therapist ensures the patient does not fall completely (protective stance). The patient’s reactive strategy to recover equilibrium is scored based on the distance and number of steps taken, or the degree of instability experienced.

Keywords

Postural perturbation, reactive stability, single-item test, fall risk assessment, KNGF guideline, mobility/movement, lower extremity, psychometrics, clinical screening.

Authors

Author ORCID Identifier: Not publicly provided in the source material for Horak FB (2004).

Affiliation Email addresses: Not publicly provided in the source material.

Correspondence Address: Correspondence is typically directed through the affiliated research institution of the primary author, Fay B. Horak, often associated with the Oregon Health & Science University (OHSU).

Permissions & Fee and Test Year

The Push and Release Test is a clinical procedure rather than a proprietary questionnaire, and thus is generally available for use without specific licensing fees for clinical application. The test methodology was formally described by Horak FB in 2004, establishing its use as a measure of reactive postural responses. The standardized Dutch adaptation was published within the KNGF-richtlijn Ziekte van Parkinson in 2016.

The official Explanation Form (Toelichtingsformulier) for the Dutch version can be downloaded here: https://scales.arabpsychology.com/wp-content/uploads/instrumenten/527_1_N.pdf (PDF).

The official Measurement Instrument (Meetinstrument) for the Dutch version can be downloaded here: https://scales.arabpsychology.com/wp-content/uploads/instrumenten/527_3_N.pdf (PDF).

Reference’s

• Horak FB. (2004). Postural orientation and equilibrium: what do we need to know about neural control of balance to prevent falls? Postural Control. Age and Ageing, 33(Suppl 1), i18–i23.
• KNGF (Koninklijk Nederlands Genootschap voor Fysiotherapie). (2016). KNGF-richtlijn Ziekte van Parkinson. Amersfoort, Netherlands: KNGF.
• The original source material points to specific documents related to the Dutch standardization of the instrument for clinical use.

Items of the Push and Release Test

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

De Push and Release Test (P&R Test) bevat 1 item waarbij de patiënt achterover leunt op de fysiotherapeut en hij deze steun plotseling weghaalt. Gemeten wordt dan de respons die de patiënt verricht om zijn evenwicht te behouden. Deze reactie wordt gemeten op een 5-puntschaal. Alleen de score “0” duidt op een normale reactie.

The standard 5-point scale (based on common clinical practice derived from similar perturbation tests) measures the following responses:

1. 0: Normal. Recovers with one step or less, or no steps required; immediate and effective postural correction.
2. 1: Slight Impairment. Recovers with 2-3 small steps, or requires a large step backward but maintains stability without assistance.
3. 2: Moderate Impairment. Requires 4 or more steps backward, or continuous shuffling, or requires assistance from the therapist to avoid falling.
4. 3: Severe Impairment. Falls backward despite the therapist’s protective stance; unable to recover balance even with multiple steps.
5. 4: Complete Instability/Fall. Spontaneous fall backward immediately upon release; requires immediate and substantial assistance to prevent injury.