Single Leg Squat Test

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Introduction[edit | edit source]

Squat man.jpeg

Single-leg squat (SLS) is a functional test, visually rated by clinicians, for assessing lower limb function as a preventive injury strategy. SLS clinical rating is a qualitative evaluation and it does not count objective outcomes as kinematics data and surface electromyography (sEMG) assessment[1].

The purpose of the SLS is to measure the strength of the lower body, particularly the quadriceps and gluteal muscle groups, and the hip stabilizer muscles[2].

The SLS test is a reasonable tool to use in preparticipation sports physical examinations to assess for dynamic knee valgus and the potential risk of lower extremity injury[3].

Image 1: Double leg squat, the SLS is similar but involves only a single leg.

Procedure[edit | edit source]

  • Clint stands on one leg while the other leg is lifted off the ground in front of the body so that the hip is flexed to approximately 45° and the knee of the non-stance leg flexed to approximately 90°.
  • The arms are held straight out in front, with the hands clasped together.
  • From this position, client squats down until about 60° knee flexion, then returns to the start position.
  • Note the leg that was tested[2].

Functionality[edit | edit source]

Hip exercise 10.png

The Single leg squat test is a clinical test, conducted in the position of single limb stance. This position occurs in many daily functions (eg walking, stair climbing, running), or in sports (eg tennis, football, netball). Remember an individual walks over 10,000 steps per day on average hence the test appears to have good face validity. The Single leg squat test is frequently used clinically to provide  a  simple  and  convenient  assessment  of neuromuscular control for the Lumbo-Pelvic region.[4]

Use[edit | edit source]

ACL non contact.PNG

The SLST is commonly used for injury prevention screening and physical rehabilitation evaluation. The test has been applied to individuals with eg patellofemoral pain syndrome, knee osteoarthritis, and anterior cruciate ligament (ACL) reconstruction. See also ACL Rehabilitation: Re-injury and Return to Sport Tests

  • Excessive medial knee deviation (MKD) during the eccentric phase of the squat is a common finding and is used as a marker of aberrant movement pattern in the knee. Hence the time to pay the most attention to MKD is at the very bottom of a squat, the start of the ascent is the most common place to spot the MKD.[5]
  • The presence of increased MKD has been related to common lower extremity dysfunctions eg anterior knee pain, and increased risk of non contact ACL injury[4].

There are also some other balance tests which require standing on one leg eg Hop Test, Single leg stance test and Stork Stand Test

Image 3: Non contact ACL ligament injury

Treatment Implications[edit | edit source]

Gluteus medius Strengthening.png

Studies suggest individuals with MKD have smaller Gluteal/Hip Add coactivation ratios and lesser dorsiflexion PROM. Individuals with MKD benefit from rehabilitation exercises focused on

The SLS clinical screenings may aid in the development of better individualized prevention and treatment plans and decrease the incidence of noncontact knee injuries.[6]

Image 4: Gluteus medius strengthening

See also Knee Injury Prevention

References[edit | edit source]

  1. Gianola S, Castellini G, Stucovitz E, Nardo A, Banfi G. Single leg squat performance in physically and non-physically active individuals: a cross-sectional study. BMC musculoskeletal disorders. 2017 Dec;18(1):1-0.Available: 4.1.2022)
  2. 2.0 2.1 Top end sports SLS Available: (accessed 4.1.2022)
  3. Ugalde V, Brockman C, Bailowitz Z, Pollard CD. Single leg squat test and its relationship to dynamic knee valgus and injury risk screening. Pm&r. 2015 Mar 1;7(3):229-35.Available: (accessed 4.1.2022)
  4. 4.0 4.1 Bailey R, Selfe J, Richards J. The single leg squat test in the assessment of musculoskeletal function: a review. Physiotherapy practice and research. 2011 Jan 1;32(2):18-23.Available: (accessed 4.1.2022)
  5. Breaking Muscle Using the Single Leg Squat to Test Leg Health Available: (accessed 5.1.2022)
  6. Mauntel TC, Begalle RL, Cram TR, Frank BS, Hirth CJ, Blackburn T, Padua DA. The effects of lower extremity muscle activation and passive range of motion on single leg squat performance. The Journal of Strength & Conditioning Research. 2013 Jul 1;27(7):1813-23.Available: (accessed 5.1.2022)