Introduction
Lower extremity musculoskeletal conditions, such as arthritis, injuries, or post-surgical recovery, significantly impact patients’ daily functioning. Consequently, the Lower Extremity Functional Scale (LEFS) serves as a vital tool for assessing functional status in these populations. Developed by Paul W. Stratford and colleagues in 1999, this 20-item questionnaire has garnered over 3,500 citations on Google Scholar, reflecting its widespread adoption in orthopedics and physical therapy. With its robust psychometric properties and ease of use, the LEFS is indispensable for clinicians and researchers.
Therefore, this article provides a comprehensive guide to the LEFS, exploring its structure, applications, and clinical value for improving patient outcomes.
Key Features of the Lower Extremity Functional Scale (LEFS)
Purpose and Use
The LEFS is designed to evaluate functional status and track improvements in patients with lower extremity musculoskeletal conditions, such as post-surgical recovery, injuries, or arthritis. Specifically, its targeted focus ensures relevance for lower limb-specific challenges, distinguishing it from general functional scales.
Target Population
The LEFS is suitable for adults aged 18 and older with lower extremity conditions, including:
- Young adults (18–24 years)
- Middle-aged adults (25–44 years)
- Older adults (45–64 years)
- Seniors (65+ years)
- College/university students
- Parents
For example, it is effective for conditions like ACL injuries, ankle fractures, and hip osteoarthritis. However, it lacks validation for neurological conditions, such as stroke or spinal cord injury.
Questionnaire Details
The LEFS comprises 20 items covering daily and recreational activities involving the lower extremities:
- Basic Mobility and Transfers (4 items): Sitting, standing, getting in/out of a car, bed-to-chair transfers.
- Walking and Ambulation (4 items): Walking short and long distances, uneven surfaces.
- Stair Navigation (2 items): Climbing and descending stairs.
- Squatting and Kneeling (2 items): Assessing difficulty in these movements.
- Advanced Physical Tasks (4 items): Running, jumping, turning, hopping.
- Heavy Household Tasks (2 items): Tasks requiring significant physical effort.
- Recreational/Work-Related Activities (2 items): Activities tied to work or leisure.
Each item is scored on a 0–4 Likert scale (0 = Extreme difficulty/unable, 4 = No difficulty), providing a comprehensive picture of functional ability.
Scoring and Interpretation
The LEFS employs a 0–4 Likert scale, with a total score ranging from 0 to 80. Higher scores indicate better function, while lower scores reflect greater disability. Key scoring details include:
- Total Score: Sum of all 20 items (maximum 80).
- Percentage of Maximal Function: (LEFS score / 80) × 100.
- Minimal Detectable Change (MDC): 9 points.
- Minimal Clinically Important Difference (MCID): 9 points.
- Interpretation Thresholds:
- Severe Impairment: ≤30/80
- Moderate Impairment: 31–48/80
For instance, a score of 25 might prompt intensive rehabilitation, while a score of 60 suggests milder limitations. Furthermore, the scale’s test-retest reliability is 0.94, with a potential error of ±5.3 points.
Administration Format
The LEFS is quick to administer, taking 5–10 minutes, making it ideal for clinical settings. It can be conducted via:
- Paper-based forms
- Digital (online) platforms
- In-person interviews
Notably, the questionnaire is self-administered, requiring no specialized training for administration or interpretation, which enhances its practicality in busy orthopedic clinics and research studies.
Applications of Lower Extremity Functional Scale (LEFS)
The LEFS is highly practical for:
- Monitoring: Tracks changes during treatment or recovery.
- Treatment Planning: Informs targeted rehabilitation strategies.
- Research: Enables studies on functional outcomes and intervention effectiveness
Other Versions And Related Questionnaires
No specific adaptations or shorter versions of the LEFS are noted. However, complementary tools include:
- FOTO: Assesses functional outcomes across multiple domains.
- WOMAC: Focuses on osteoarthritis-related functional limitations.
- SF-36 Physical Function: Measures general physical function.
- FAAM: Evaluates foot and ankle function.
- Lower Limb Functional Index (LLFI): Assesses lower limb function.
- Olerud-Molander Ankle Score: Specific to ankle injuries.
Language and availability
To enhance accessibility, the LEFS is available in multiple languages, including:
- Arabic
- English
- Spanish
- French
- German
- Portuguese and others
This multilingual support facilitates its use in diverse clinical and research contexts.
The LEFS is accessible and cost-effective for various uses,it is Free for non-commercial use such as clinical or academic research purposes.
Reliability and Validity
The LEFS demonstrates high reliability and validity, with a Cronbach’s alpha ranges between 0.90–0.96, indicating excellent internal consistency. Moreover, validation studies confirm its sensitivity to change, surpassing tools like the SF-36. Thus, its robust psychometric properties make it a trusted choice for monitoring functional outcomes.
- Original validation study study link
- Brazilian Portuguese validation study link
- German validation study link
Limitations and Considerations
Despite its strengths, the LEFS has a few limitations:
- Self-Report: Responses may be influenced by personal interpretation or social desirability bias.
- Ceiling Effects: Less effective in high-functioning populations due to limited sensitivity at higher scores.
- Not Validated for Neurological Conditions: Inapplicable for conditions like stroke or spinal cord injury.
- Limited Validation Studies: Further validation is needed for certain populations or conditions to ensure broader applicability.
Additional Resources
For more information on the LEFS:
- Original validation study
- Further studies:
- Validation of LEFS in patients with anterior knee pain study link
- Cross-cultural validation study link
- Access the LEFS as PDF
- For inquiries, contact Shirley Ryan AbilityLab: +1-844-355-ABLE or at this website
Frequently Asked Questions (FAQ)
- Who can use the LEFS?
Clinicians, researchers, and healthcare providers use the LEFS for adults aged 18 and older with lower extremity musculoskeletal conditions. - How long does it take to complete the LEFS?
Patients typically take 5 to 10 minutes to complete the LEFS, making it feasible for clinical and research settings. - How is the LEFS administered?
Healthcare teams can administer it via paper, digital, mobile app, or in-person interviews, offering flexibility. - Is there any cost to using the LEFS?
The LEFS is free for non-commercial use, available at no cost for clinical or academic research purposes.
A word from ResRef about Lower Extremity Functional Scale (LEFS)
The Lower Extremity Functional Scale (LEFS) is a validated, easy-to-use tool for assessing lower extremity function in adults. It is self-administered, quick, and free, with strong reliability, internal consistency, and responsiveness. While excellent for monitoring treatment and conducting research, caution is advised when interpreting scores in high-functioning populations.
References
- Binkley, J. M., Stratford, P. W., Lott, S. A., & Riddle, D. L. (1999). The Lower Extremity Functional Scale (LEFS): Scale development, measurement properties, and clinical application. Physical Therapy, 79(4), 371–383. link
- Metsavaht L, Leporace G, Riberto M, Sposito MM, Del Castillo LN, Oliveira LP, Batista LA. Translation and cross-cultural adaptation of the lower extremity functional scale into a Brazilian Portuguese version and validation on patients with knee injuries. J Orthop Sports Phys Ther. 2012 Nov;42(11):932-9. doi: 10.2519/jospt.2012.4101. Epub 2012 Oct 9. PMID: 23047028. link
- Naal FD, Impellizzeri FM, Torka S, Wellauer V, Leunig M, von Eisenhart-Rothe R. The German Lower Extremity Functional Scale (LEFS) is reliable, valid and responsive in patients undergoing hip or knee replacement. Qual Life Res. 2015 Feb;24(2):405-10. doi: 10.1007/s11136-014-0777-6. Epub 2014 Aug 10. PMID: 25108549. link
- Watson CJ, Propps M, Ratner J, Zeigler DL, Horton P, Smith SS. Reliability and responsiveness of the lower extremity functional scale and the anterior knee pain scale in patients with anterior knee pain. J Orthop Sports Phys Ther. 2005 Mar;35(3):136-46. doi: 10.2519/jospt.2005.35.3.136. PMID: 15839307 link
- Pua YH, Cowan SM, Wrigley TV, Bennell KL. The Lower Extremity Functional Scale could be an alternative to the Western Ontario and McMaster Universities Osteoarthritis Index physical function scale. J Clin Epidemiol. 2009 Oct;62(10):1103-11. doi: 10.1016/j.jclinepi.2008.11.011. Epub 2009 Mar 17. PMID: 19282145. link
1 thought on “Lower Extremity Functional Scale (LEFS): A Full Guide for Researchers and Clinicians.”
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