Single Leg Stance Test (SLS)

The Single Leg Stance Test (SLS) is a simple yet highly informative tool for assessing static balance and postural control in adults and older adults. The test involves standing on one leg without support and measuring how long the individual can maintain the position before balance is lost – either by putting the foot down or moving the hands away from the hips.

SLS is one of the most widely used screening tests for fall risk, especially in the elderly population¹.

Advantages and Limitations

Advantages:

• Requires minimal equipment

• Quick and easy to perform

• Provides predictive information on fall risk and functional decline

Limitations:

• Does not provide a complete picture of balance function

• Low sensitivity for detecting small changes over time, particularly in older adults without neurological impairment²

• Should always be combined with other balance and mobility assessments

Test Procedure

1. Patient stands upright on one leg with eyes open and hands placed on the hips.

2. Timing starts when the non-weight-bearing foot is lifted from the ground.

3. Timing ends when the foot touches the ground or when hands leave the hips.

4. Results are measured in seconds and represent the individual’s ability to maintain unilateral stance.

Recommendations:

• Allow one practice attempt before measurement.

• Perform at least two trials per leg; record the best value.

Age-Adjusted Cut-off Values and Clinical Meaning

Research shows that one-leg balance capacity declines with age, but there are clear threshold values with clinical importance:

• < 5 seconds: Strong predictor of falls in older adults³

• ≥ 10 seconds (age 50+): Associated with lower mortality and better overall balance function⁴

Clinical Applications

The SLS test is widely used in physiotherapy and rehabilitation, particularly for:

• Osteoarthritis of the knee or hip⁵

• Neurological conditions such as Parkinson’s disease, multiple sclerosis, dementia, and post-stroke⁶

• Post-operative rehabilitation after knee or hip arthroplasty⁵

• Geriatric populations with instability or prior falls

Balance in single-leg stance depends on sensory input, lower limb strength, and anticipatory postural adjustments (APA). Impairments in any of these systems will reduce performance, making SLS a valuable functional measure.

Interpretation in Practice

• < 5 seconds: Red flag for older adults → initiate fall-prevention strategies (strength, balance training, home safety evaluation).

• 5–10 seconds: Grey zone → interpret with other clinical findings.

• > 10 seconds: Normal for healthy adults and older adults.

Clinical Example

A 74-year-old woman with knee osteoarthritis completes the SLS test and manages 4.6 seconds before needing support. This indicates elevated fall risk. She is prescribed targeted balance and strength training plus a home safety review.

After 8 weeks of intervention, her performance improves to 9.2 seconds, representing a clinically meaningful change (MCID) for this group⁷.

Summary

The Single Leg Stance Test is a cost-effective and reliable screening tool for assessing static balance and fall risk. It is easy to administer, quick to interpret, and provides valuable information for both prevention and rehabilitation.

Although it does not capture all dimensions of balance and mobility, it remains a vital supplement to the clinical toolbox, particularly for physiotherapists working with older adults, neurological patients, and those with musculoskeletal conditions.

Sources:

1. Springer BA, Marin RH, Cyhan T, Roberts H, Gill NW. Normative verdier for Unipedal Stance Test med åpne og lukkede øyne. Journal of Geriatric Physical Therapy. 2007;30(1):8–15. https://doi.org/10.1519/00139143-200704000-00003

2. Vellas BJ, Wayne SJ, Romero L, Baumgartner RN, Rubenstein LZ, Garry PJ. Ettbensbalanse som prediktor for fallskader hos eldre. Journal of the American Geriatrics Society. 1997 Jun;45(6):735–8.

3. Araujo CG, De Souza E Silva CG, Laukkanen JA, Singh MF, Kunutsor SK, Myers J, et al. 10 sekunders ettbensbalanse forutser overlevelse hos middelaldrende og eldre. British Journal of Sports Medicine. 2022 Jun;56(17):975–80.

4. Hunt MA, McManus FJ, Hinman RS, Bennell KL. Prediktorer for ettbensbalanse hos personer med medial artrose i kneet. Arthritis Care & Research. 2010 Apr;62(4):496–500. https://onlinelibrary.wiley.com/doi/full/10.1002/acr.20046

5. Zhang C, Talaber A, Truong M, Vargas BB. KD Balance: Objektivt mål på balanse i tandem og dobbelt benstilling. Digital Health. 2019 Oct;5:2055207619885573. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831964/

6. Bonora G, Mancini M, Carpinella I, Chiari L, Ferrarin M, Nutt JG, Horak FB. Forberedende posturale justeringer ved ettbensstående hos personer med parkinsonisme. Frontiers in Neurology. 2017 Jul;8:361. https://www.frontiersin.org/articles/10.3389/fneur.2017.00361/full

7. Sarac DC, Unver B, Karatosun V. Validitet og reliabilitet for balansetester ved total kneprotese. Knee Surgery & Related Research. 2022 Mar;34(1).

8. Choi YM, Dobson F, Martin J, Bennell KL, Hinman RS. Inter- og intrarater reliabilitet for balansetester hos personer med hofteartrose. Physical Therapy. 2014 May;94(5):696–704.

9. Goldberg A, Casby A, Wasielewski M. Minste målbare endring i ettbensståendetid hos eldre. Gait & Posture. 2011 Apr;33(4):737–9.