Description

The Push and Release Test (PART) is a brief clinical test used to assess dynamic balance, postural stability, and reactive corrective responses following a sudden disturbance of balance. It was developed as an alternative approach to the traditional Pull Test, with the aim of producing a more standardized backward perturbation of balance.

The test is particularly used in the assessment of individuals with Parkinson’s disease and other disorders affecting postural control, as it allows direct observation of the individual’s ability to initiate effective corrective stepping responses.

Objective

The primary objective of the PART is to assess the individual’s ability to recover balance following a sudden backward perturbation. More specifically, it evaluates whether the person can rapidly and effectively activate appropriate reactive strategies, primarily through corrective stepping, in order to prevent a fall.

The assessment of reactive balance is particularly important because impaired postural control is associated with an increased risk of falls, reduced mobility, and decreased functional independence.

Administration Procedure

The individual stands upright in a comfortable position with the eyes open. The examiner stands behind the participant and places their hands against the participant’s shoulder blades. The participant is instructed to gradually lean backward against the examiner’s hands while the examiner supports the individual’s weight and allows a controlled backward inclination of the trunk.

The examiner then suddenly removes their hands, producing a backward loss of balance. The participant is required to regain stability independently using any necessary corrective strategy, including compensatory stepping.

For safety reasons, the examiner must remain appropriately positioned to prevent an actual fall.

Scoring

Performance is generally evaluated using a 5-point scale ranging from 0 to 4, with higher scores indicating greater impairment of reactive balance:

0: Recovers balance independently with one normal corrective step.

1: Requires two to three small backward steps but regains balance independently.

2: Requires four or more steps but does not need external assistance.

3: Attempts corrective stepping but requires assistance to prevent a fall.

4: Falls without an effective attempt to take a corrective step or is unable to stand without support.

Therefore, lower scores represent better postural control, whereas higher scores indicate greater postural instability.

Psychometric Properties

The initial evaluation of the PART in individuals with Parkinson’s disease indicated that it may provide a more sensitive and consistent measure of postural stability than the traditional Pull Test. Satisfactory inter-rater reliability and associations between PART performance and a history of falls have also been reported.

Studies have further suggested that the PART may demonstrate good ability to distinguish between individuals with Parkinson’s disease who are fallers and non-fallers, although its diagnostic performance may vary depending on medication status.

Recent Research Findings and Limitations

Despite the clinical usefulness of the PART, contemporary research highlights the need for greater standardization of the administration procedure. A recent study involving individuals with Parkinson’s disease reported substantial variability both between different examiners and across repeated administrations by the same examiner. Variability in the way the perturbation is generated may therefore influence the resulting score and should be considered when the test is used in clinical practice or research.

In addition, the PART represents a single-dimensional assessment of reactive balance and does not provide a comprehensive evaluation of all mechanisms involved in balance control. Therefore, when a broader functional assessment is required, it is preferable to use the PART in combination with other clinical measures rather than as the sole indicator of overall fall risk.

Applications

The PART can be used in both clinical practice and research to assess postural instability, monitor changes in functional balance, and investigate the effectiveness of therapeutic or rehabilitation interventions. It is particularly relevant in Parkinson’s disease, where postural instability is an important contributor to reduced mobility and increased fall risk.

Its simplicity, short administration time, and lack of need for specialized equipment make the test practical for clinical and research settings. However, interpretation of the results should take into account the individual’s fall history and overall clinical presentation.

References

Jacobs JV, Horak FB, Van Tran K, Nutt JG. An alternative clinical postural stability test for patients with Parkinson’s disease. Journal of Neurology. 2006;253(11):1404–1413. doi:10.1007/s00415-006-0224-x.

Valkovic P, Brozová H, Bötzel K, Růzicka E, Benetin J. Push-and-release test predicts Parkinson fallers and nonfallers better than the pull test: comparison in OFF and ON medication states. Movement Disorders. 2008;23(10):1453–1457. doi:10.1002/mds.22131.

Nonnekes J, Goselink R, Weerdesteyn V, Bloem BR. The Retropulsion Test: A good evaluation of postural instability in Parkinson’s disease? Journal of Parkinson’s Disease. 2015;5(1):43–47. doi:10.3233/JPD-140514.

Jansen JAF, Bloem BR, Keijsers N, Nonnekes J, Weerdesteyn V. Presence and origin of variability of the pull test and push-and-release test in people with Parkinson’s disease. Journal of Neurology. 2025;272:258. doi:10.1007/s00415-025-12974-9.