Sage Journals: Discover world-class research

Abstract

Background:

The simplified Chinese Lower Extremity Functional Scale (SC-LEFS) is a patient-reported outcome measure specifically developed for Chinese-speaking patients to assess functional status in those with lower extremity musculoskeletal disorders. However, to date, no studies have specifically examined the reliability and responsiveness of the SC-LEFS in nonarthritic musculoskeletal injuries.

Purpose:

To define the minimal detectable change (MDC) as a measure of test-retest reliability and the substantial clinical benefit (SCB) as a measure of responsiveness for the SC-LEFS in patients with nonarthritic lower extremity musculoskeletal injuries.

Study Design:

Cohort study (diagnosis); Level of evidence, 3.

Methods:

Patients aged between 18 and 50 years with a lower extremity musculoskeletal injury who were referred for physical therapy visits completed the SC-LEFS at the initial assessment and at the 4-week follow-up. Patients were classified into “stable,”“improved,” and “not improved” groups based on self-reported changes at the 4-week follow-up. The “stable” group was used to establish the MDC value for test-retest reliability. The “improved” and “not improved” groups were used to determine the SCB value for responsiveness.

Results:

A total of 763 patients (44.8% women), with a mean age of 32.9 (SD, 9.4) years, were included. Using the “stable” group (n = 40), excellent test-retest reliability was demonstrated with an intraclass correlation coefficient of 0.98 and an MDC of 5.1 points. To evaluate the responsiveness, the “improved” (n = 497) and “not improved” (n = 266) groups were analyzed. Receiver operator characteristic analysis found an SCB value of 9.5 points on the SC-LEFS. This change score could differentiate those “improved” from those “not improved” with a sensitivity of 0.68, specificity of 0.71, and area under the curve of 0.75 (95% CI, 0.71-0.78).

Conclusion:

This study offers evidence of test-retest reliability and responsiveness with MDC and SCB values for the SC-LEFS in Chinese-speaking patients with nonarthritic lower musculoskeletal extremity injuries. Clinicians should consider 5.1 points as the measurement error and 9.5 points as the threshold for clinically meaningful improvement on the SC-LEFS in patients with lower extremity musculoskeletal injuries over a 4-week treatment period.

Keywords

minimal detectable change patient-reported outcome measure psychometric properties substantial clinical benefit

The Lower Extremity Functional Scale (LEFS) is a patient-reported outcome measure (PROM) used for assessing the functional status and treatment outcomes of those with lower extremity musculoskeletal injuries.^4,16,33 Two systematic reviews supported the use of the original English LEFS with evidence for reliability, validity, and responsiveness.^16,33 In addition to English, the LEFS is available in 11 other languages—including the Simplified Chinese version of the Lower Extremity Functional Scale (SC-LEFS).^{2,5-8,12,17-20,24,26} Evidence for test-retest reliability and validity is available for the SC-LEFS in elderly patients with a variety of lower extremity musculoskeletal injuries.^31,32 However, the responsiveness of the SC-LEFS has only been studied in patients with knee osteoarthritis.³¹ Further evidence is needed to define the reliability and responsiveness of the SC-LEFS in patients with nonarthritic musculoskeletal injuries.

Test-retest reliability is a measure of a score's stability over time for patients who have not changed. Related to the reliability, a value for minimal detectable change (MDC) will define the change in score beyond the measurement error and represent a true change in patient status over time.^14,25,30 The responsiveness refers to an instrument's ability to detect meaningful changes in a patient’s condition over time. This can be defined by values for substantial clinical benefit (SCB), which represent the improvement in the overall state that a patient considers to be important.^9-11,22 Current evidence supporting the reliability and responsiveness of the SC-LEFS is limited and includes only 2 studies.^31,32 One study³² defined the MDC of the SC-LEFS in patients aged 53.5 ± 18 years with a variety of lower extremity musculoskeletal injuries over 2 weeks. The second study investigated the responsiveness of the SC-LEFS over 6 months postoperatively in patients aged 65.1 ± 8.2 years with knee osteoarthritis.³¹ Both studies investigated older patients, underscoring a research gap for other demographics.^31,32 Consequently, studies are needed to define the MDC and SCB values of the SC-LEFS in young patients with nonarthritic musculoskeletal injuries.

Psychometric evidence to support a PROM is context-dependent and can only be generalized to the clinical patients used in the supporting research studies. Defining the MDC and SCB values for the SC-LEFS for Chinese-speaking patients with nonarthritic musculoskeletal lower extremity injuries can offer valuable information regarding the effectiveness of treatment interventions. This study aimed to provide supporting evidence for the reliability and responsiveness of the SC-LEFS in Chinese-speaking patients with nonarthritic musculoskeletal lower extremity injuries.

Methods

This longitudinal prospective study collected data from 10 physical therapy clinics in the Republic of China. All patients signed an informed consent approved by the ethics committee of the Rehabilitation Hospital affiliated with the Fujian University of Traditional Chinese Medicine Institutional Review Board before participating in the study. Patients aged between 18 and 50 years with lower extremity musculoskeletal injuries met the inclusion criteria. This age range was selected specifically because this demographic typically represents the nonarthritic musculoskeletal injuries population. The exclusion criteria included patients with weightbearing restrictions, primarily osteoarthritis, neurological disorders, inability to comprehend written Chinese, and those not completing 4 weeks of physical therapy. Age, sex, surgical history, and symptom duration were self-reported by patients. Diagnoses were defined using the International Classification of Diseases Codes 11^th Revision (ICD-11).

During patients’ first physical therapy visits, they completed the SC-LEFS as part of the initial assessment. After 4 weeks of physical therapy, patients were again given the SC-LEFS. The SC-LEFS consists of 20 items scored from 0 (extreme difficulty or inability to perform an activity) to 4 (no difficulty). Individual item scores are added to yield a total score, which ranges from 0 (extreme limitations) to 80 (no functional limitations).^31,32 Patients were also provided with the question, “How do you feel your functional status has changed when compared with the first time you completed the SC-LEFS?” The following responses were provided: greatly worse, worse, slightly worse, no change, slightly improved, improved, or much improved. To establish the MDC, patients who reported no change were classified in the “stable” group. To establish the SCB change score for improvement, patients were classified as either “improved” (those who reported being improved or much improved) or “not improved” (those who reported being slightly improved, no change, greatly worse, worse, or slightly worse).

The initial and 4-week SC-LEFS scores in the “stable” group were used to provide evidence of test-retest reliability using the intraclass correlation coefficient²⁸ (ICC, 2,1). Standard error of measurement (SEM) was calculated as follows: SEM = standard deviation (S) *√(1 – ICC value). The MDC₉₅ was calculated²⁹ as follows: MDC₉₅ = SEM *√2. Responsiveness can be defined by the SCB value, representing the improvement in functional status that a patient considers to be important.^9-11,22 An anchor-based method was used to calculate the SCB for improved values. The anchor-based method uses patient self-report outcomes as an anchor to determine the clinical significance of observed changes in outcome measures.^21,22 Receiver operator characteristic (ROC) curve analysis determined sensitivity and specificity values for changes in the score that differentiated the “improved” from “not improved” groups. The Youden index was utilized to determine the cutoff change in the score value associated with the optimal sensitivity and specificity values.²⁷ This SCB change in score value is likely to represent a patient who reported being “improved” from those who reported being “not improved.” The accuracy of this cutoff value was defined with a calculation of the area under the curve (AUC) at a 95% CI.^3,13 The AUC of the ROC analysis evaluates the instrument’s association and accuracy to differentiate between groups.¹³ An AUC value exceeding 0.70 and a 95% CI that does not include 0.5 are considered acceptable levels of responsiveness.^13,23 The SPSS software package Version 27 (IBM) was used for statistical analysis.

Results

After excluding 11 (1%) patients because of missing data, a final sample size of 763 was used for the analysis. Demographic information—including age, sex, duration of symptoms, mean initial SC-LEFS scores, and mean of 4-week SC-LEFS scores—are provided in Table 1. Musculoskeletal injuries, as diagnosed with ICD-11 codes, are presented in Table 2. The ICC was determined to be 0.98 (95% CI, 0.97-0.99; P < .01), with a SEM of 1.8 and an MDC₉₅ of 5.1 points (Table 3). Based on patient reports, 494 (64.7%) patients “improved,” while 269 (37.3%) did “not improve.” The ROC analysis found that an SCB cutoff score for improvement of 9.5 points on the SC-LEFS exhibited a sensitivity of 0.68 (95% CI, 0.64-.71), specificity of 0.71 (95% CI, 0.67-0.74), and an AUC of 0.75 (95% CI, 0.71-0.78; P < .01) (Table 4). The ROC curve is shown in Figure 1.

Table 1

Demographic Characteristics of Patients^a

	Total Sample	Stable Group	Improved Group	Not Improved Group
Number of patients	763	40	494	269
Age, y	32.9 (9.4)	37.2 (8.7)	33.1 (9.3)	35.3 (9.5)
Female	342 (44.8)	17 (42.5)	325 (45)	121 (45.5)
Male	421 (54.2)	23 (57.5)	398 (55)	145 (54.5)
Symptom duration, days	173 (362)	306 (620)	155.8 (346.8)	207 (288)
Surgery	251 (32.9)	5 (12.5)	246 (34)	87 (32.7)
Initial mean LEFS	49.5 (15.2)	61.5 (13.8)	48.3 (15.7)	51.7 (13.9)
4-week mean LEFS	62.7 (12.4)	63.5 (13.5)	64.7 (11.9)	59 (12.5)

Data are presented as mean (SD) or n (%). LEFS, lower extremity functional scale.

Table 2

Patients’ Diagnosis Information^a

Diagnosis (ICD-11 Code)
Dislocation, strain, or sprain of joints or ligaments of the knee (NC93)	178 (23.3)
Dislocation, strain, or sprain of joints or ligaments at the ankle or foot level (ND 14)	146 (19.1)
Fractures of the hip, thigh, and lower leg—including ankle and foot (NC72, NC92, and ND13)	143 (18.7)
Injury of the muscle, fascia, tendon, or bursa at the lower leg level (NC 96)	127 (16.5)
Certain specified joint disorders of the limbs (FA30-FA38)	85 (11.1)
Injury of the muscle, fascia, tendon, or bursa at the hip or thigh level (NC 76)	75 (9.8)
Combined injury of the bone fracture, ligament, and soft tissue (NC72, NC92 ND13, NC93, ND 14, NC76, and NC 96)	9 (0.9)

Data are presented as n (%). ICD, International Classification of Diseases.

Table 3

Test-Retest Reliability for Simplified Chinese Version^a

ICC (95% CI)	Significance	SEM	MDC₉₅
0.98 (0.97-0.99)	<.005	1.83	5.1

ICC, intraclass correlation coefficient; MDC, minimal detectable change.

Table 4

Responsiveness for Simplified Chinese Version^a

Improved	Not Improved	SCB Value	Specificity (95% CI)	Sensitivity (95% CI)	AUC (95% CI)	Significance
494	269	9.5	0.71 (0.67-0.74)	0.68 (0.64-0.71)	0.75 (0.71-0.78)	<.001

AUC, area under the curve; SCB, substantial clinical benefit.

Figure 1.

ROC curves for SCB values of improvement in the SC-LEFS after a 4-week follow-up. ROC, receiver operating characteristic curves; SCB, substantial clinical benefit; SC-LEFS, Simplified Chinese Version of the Lower Extremity Functional Scale.

Discussion

This study provides evidence that the SC-LEFS is a reliable and responsive PROM for evaluating changes in lower extremity function among Chinese-speaking patients with nonarthritic lower extremity musculoskeletal injuries. This study revealed excellent test-retest reliability with an MDC₉₅ value of 5.1 points over 4 weeks. An anchor-based method using patient reports found that an SCB change score of 9.5 points could accurately differentiate those who reported being “improved” from those “not improved” after 4 weeks of physical therapy.

The ICC value of 0.98 and MDC₉₅ of 5.1 points over 4 weeks found in this study were similar to previous studies.^12,16 The English LEFS demonstrated excellent test-retest reliability in patients with a variety of lower extremity musculoskeletal injuries throughout 1 to 3 weeks, with an ICC value ranging from 0.87 to 0.94 in a systematic review by Mehta et al.¹⁶ The systematic review by Mehta et al¹⁶ also reported the MDC₉₅ of English LEFS to range from 2.18 to 18.1 points across 8 studies in patients with various lower extremity musculoskeletal injuries and retest periods ranging from 2 days to 12 months. Another study that was not included in the Mehta et al¹⁶ systematic review found excellent test-retest reliability, with an ICC value of 0.98, and determined an MDC₉₅ of 9 points in Arabic LEFS scores for those with an anterior cruciate ligament (ACL) injury over 5 days.¹² Differences in MDC values may be attributed to factors such as follow-up time and patient characteristics. In addition, the criteria for including patients as the stable group may explain the variation in MDC scores. In the present study, patients who reported “no change” were classified as the stable group. Other studies included patients reporting “mild improvement,”“no change,” or “mild worsening” in their stable group.¹⁶

While the MDC value defines the measurement error in patient status over time, the SCB represents a change in status that a patient perceives as meaningful. A systematic review conducted by Mehta et al¹⁶ reported SCB values ranging between 4.2 and 12.5 points on the English LEFS for patients with a variety of lower extremity disorders. Studies not included in this systematic review reported an SCB of 9 points on the Arabic LEFS (AUC, 0.781 [95% CI, 0.676-0.886]) for those with an ACL injury¹² and 12 points (AUC, 0.97 [95% CI, 0.89-1]) on the English LEFS for patients with insertional Achilles tendinopathy.¹⁵ Abbott and Schmitt¹ conducted a study on the responsiveness of the English LEFS between the period of the initial and final physical therapy visit on 546 patients with various lower extremity musculoskeletal injuries. This study used 3 levels of change, “somewhat better,”“moderately better,” and “quite a bit better,” to define 3 distinct SCB change values. The inclusion criteria for the Abbott and Schmitt study was similar to this study in that it included patients with a variety of lower-extremity musculoskeletal injuries. This study found an SCB of 9.5 points on the SC-LEFS over 4 weeks, which was similar to Abbott and Schmitt's finding of an SCB of 9 points on the English LEFS for those patients reporting to be “quite a bit better.” However, the time frame of 4 weeks used for assessing responsiveness in this study differs from the Abbott and Schmitt study, which measured responsiveness from admission to discharge. In addition, the Abbott and Schmitt study included those with a mean age of 49 ± 17 years and with osteoarthritis. In contrast, the present study focused on a younger and nonarthritic musculoskeletal injuries demographic and specifically excluded those with osteoarthritis.

The MDC and SCB values are important when assessing a patient's change in score on a PROM over time. A change in the SC-LEFS score that surpasses the MDC would be considered beyond the measurement error from repeated measurements. According to this study, if a patient initially scores 50 out of 80 on the SC-LEFS, a score that exceeds 55 over 4 weeks would be considered beyond the measurement error. Similarly, using the SCB established for the SC-LEFS scale, if the same patient's SC-LEFS score increased to 60 over 4 weeks, it would indicate a high probability that the patient would perceive themselves as “improved.” When interpreting the term “improved,” it is important to note that this study operationally defined it as the patient’s perceived change in status as “much improved” or “improved” after 4 weeks of physical therapy. As done in similar studies, the SCB value in this study is determined by patients’ self-reported perceptions of their functional status change without incorporating additional objective data or other PROMs.³³ When clinicians interpret the SCB values in this study, they should be aware that this value is anchored in patient self-reports, which can be influenced by bias and may not accurately reflect objective changes in function.³³

Conclusion

This study demonstrates the test-retest reliability and provides unique SCB change score values for the SC-LEFS for Chinese-speaking patients with nonarthritic lower extremity musculoskeletal injuries. A score change of 9.5 points could differentiate those who report being “improved” from those “not improved” after 4 weeks of physical therapy. The findings offer clinicians and researchers evidence of the reliability and responsiveness of the SC-LEFS, suggesting that it may be beneficial to clinicians in evaluating treatment outcomes.

Authors

Yongni Zhang, PT (Duquesne-China Health Institute, Duquesne University, Pittsburgh, Pennsylvania, USA); Dongmei Ai, PT (Department of Rehabilitation Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China); Yuan Gao, PT (Department of Rehabilitation Medicine, Zibo Traditional Chinese Medicine Hospital, Zibo, Shandong, China); Weimin Li, PT (Department of Rehabilitation Medicine, The Second Affiliated Hospital of Hainan Medical University, Hainan, China); Yixiong Yi, MD (Department of Rehabilitation Center, Anxi County Hospital of Traditional Chinese Medicine, Quanzhou, Fujian, China); Xiongwei Xu, PT (Department of Rehabilitation Center, Kunshan Rehabilitation Hospital, Kunshan, Jiangsu, China); Haoyu Hu, PT (Shanghai University of Sport, Shanghai, China); NanNan Zhang, PT (Department of Sport Therapy, Shaanxi Rehabilitation Hospital, Shaanxi, China); Songbin Yang, MD, PhD (Department of Rehabilitation Medicine, Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital, Shanghai, China); Xiaowen Lian, MD ( Department of Rehabilitation Assessment, Rehabilitation Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China; Fujian Key Laboratory of Rehabilitation Technology, Fuzhou, Fujian, China); YuZhang Wang, PT, Msc (Department of Rehabilitation Medicine, Beijing Jishuitan Hospital, Capital Medical University, Beijing, China); RobRoy L. Martin. PT, PhD (Department of Physical Therapy, Duquesne University, Pennsylvania, USA; UPMC Center for Sports Medicine, Pennsylvania, USA), and Xin Zhang, DPT (School of Medicine, Tongji University, Shanghai, China).

Footnotes

Final revision submitted August 28, 2024; accepted October 7, 2024.

The authors have declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

ORCID iD

Yongni Zhang

References

Abbott

Schmitt

Minimum important differences for the patient-specific functional scale, 4 region-specific outcome measures, and the numeric pain rating scale. J Orthop Sports Phys Ther. 2014;44(8):560-564.

Alnahdi

Alrashid

Alkhaldi

Aldali

AZ.

Cross-cultural adaptation, validity, and reliability of the Arabic version of the Lower Extremity Functional Scale. Disabil Rehabil. 2016;38(9):897-904.

Beaton

DE.

Understanding the relevance of measured change through studies of responsiveness. Spine (Phila Pa 1976). 2000;25(24):3192-3199.

Binkley

Stratford

Lott

Riddle

DL.

The Lower Extremity Functional Scale (LEFS): scale development, measurement properties, and clinical application. North American Orthopaedic Rehabilitation Research Network. Phys Ther. 1999;79(4):371-383.

Bravini

Giordano

Sartorio

Ferriero

Vercelli

Rasch analysis of the Italian Lower Extremity Functional Scale: insights on dimensionality and suggestions for an improved 15-item version. Clin Rehabil. 2017;31(4):532-543.

Cacchio

De Blasis

Necozione

, et al. The Italian version of the lower extremity functional scale was reliable, valid, and responsive. J Clin Epidemiol. 2010;63(5):550-557.

Citaker

Kafa

Hazar Kanik

Ugurlu

Kafa

Tuna

Translation, cross-cultural adaptation, and validation of the Turkish version of the Lower Extremity Functional Scale on patients with knee injuries. Arch Orthop Trauma Surg. 2016;136(3):389-395.

Cruz-Díaz

Lomas-Vega

Osuna-Pérez

, et al. The Spanish lower extremity functional scale: a reliable, valid and responsive questionnaire to assess musculoskeletal disorders in the lower extremity. Disabil Rehabil. 2014;36(23):2005-2011.

Glassman

Copay

Berven

Polly

Subach

Carreon

LY.

Defining substantial clinical benefit following lumbar spine arthrodesis. J Bone Joint Surg Am. 2008;90(9):1839-1847.

10.

Harris

Brand

Cote

Faucett

Dhawan

Research pearls: the significance of statistics and perils of pooling. Part 1: clinical versus statistical significance. Arthroscopy. 2017;33(6):1102-1112.

11.

Katz

Paillard

Ekman

Determining the clinical importance of treatment benefits for interventions for painful orthopedic conditions. J Orthop Surg Res. 2015;10:24.

12.

Korakakis

Saretsky

Whiteley

, et al. Translation into modern standard Arabic, cross-cultural adaptation and psychometric properties’ evaluation of the Lower Extremity Functional Scale (LEFS) in Arabic-speaking athletes with anterior cruciate ligament (ACL) injury. PLoS One. 2019;14(6):e0217791.

13.

Lasko

Bhagwat

Zou

Ohno-Machado

The use of receiver operating characteristic curves in biomedical informatics. J Biomed Inform. 2005;38(5):404-415.

14.

Martin

Irrgang

JJ.

A survey of self-reported outcome instruments for the foot and ankle. J Orthop Sports Phys Ther. 2007;37(2):72-84.

15.

McCormack

Underwood

Slaven

Cappaert

The minimum clinically important difference on the visa-a and lefs for patients with insertional achilles tendinopathy. Int J Sports Phys Ther. 2015;10(5):639-644.

16.

Mehta

Fulton

Quach

, et al. Measurement properties of the lower extremity functional scale: a systematic review. J Orthop Sports Phys Ther. 2016;46(3):200-216.

17.

Metsavaht

Leporace

Riberto

, et al. 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;42(11):932-939.

18.

Mohd Yunus

Musa

Nazri

MY.

Construct and criterion validity of the Malaysia version of Lower Extremity Functional Scale (LEFS). Asia Pac J Sports Med Arthrosc Rehabil Technol. 2017;10:8-11.

19.

Naal

Impellizzeri

Torka

, et al. The German Lower Extremity Functional Scale (LEFS) is reliable, valid and responsive in patients undergoing hip or knee replacement. Qual Life Res. 2015;24(2):405-410.

20.

Negahban

Hessam

Tabatabaei

, et al. Reliability and validity of the Persian lower extremity functional scale (LEFS) in a heterogeneous sample of outpatients with lower limb musculoskeletal disorders. Disabil Rehabil. 2014;36(1):10-15.

21.

Nwachukwu

Chang

Fields

, et al. Defining the “substantial clinical benefit” after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med. 2017;45(6):1297-1303.

22.

Nwachukwu

Chang

Rotter

, et al. Minimal clinically important difference and substantial clinical benefit after revision hip arthroscopy. Arthroscopy. 2018;34(6):1862-1868.

23.

Park

Goo

CH.

Receiver operating characteristic (ROC) curve: practical review for radiologists. Korean J Radiol. 2004;5(1):11-18.

24.

Pereira

Dias

Mazuquin

, et al. Translation, cross-cultural adaptation and analysis of the psychometric properties of the lower extremity functional scale (LEFS): LEFS- BRAZIL. Braz J Phys Ther. 2013;17(3):272-280.

25.

Prinsen

CAC

Mokkink

Bouter

, et al. COSMIN guideline for systematic reviews of patient-reported outcome measures. Qual Life Res. 2018;27(5):1147-1157.

26.

Repo

Tukiainen

Roine

, et al. Reliability and validity of the Finnish version of the Lower Extremity Functional Scale (LEFS). Disabil Rehabil. 2017;39(12):1228-1234.

27.

Schisterman

Perkins

Liu

Bondell

Optimal cut-point and its corresponding Youden Index to discriminate individuals using pooled blood samples. Epidemiology. 2005;16(1):73-81.

28.

Shrout

Fleiss

JL.

Intraclass correlations: uses in assessing rater reliability. Psychol Bull. 1979;86(2):420-428.

29.

Stratford

Binkley

Solomon

, et al. Defining the minimum level of detectable change for the Roland-Morris questionnaire. Phys Ther. 1996;76(4):359-365.

30.

Ueland

Disantis

Carreira

Martin

RL.

Patient-reported outcome measures and clinically important outcome values in hip arthroscopy: a systematic review. JBJS Rev. 2021;9(1):e20.00084.

31.

Wang

Zhang

Feng

Tong

Cross-cultural adaption and validation of simplified Chinese version of the lower extremity function scale in patients with knee osteoarthritis. Clin Rheumatol. 2020;39(10):3041-3048.

32.

Zhang

Liu

Yuan

, et al. Cross-cultural adaptation and validation of the simplified Chinese version of the Lower Extremity Functional Scale. Biomed Res Int. 2020;2020:1421429.

33.

Zhang

Zang

Martin

. Clinically most relevant psychometric properties of the Lower Extremity Functional Scale: a systematic review. Disabil Rehabil. 2024:1-7.

Test-Retest Reliability and Responsiveness for the Simplified Chinese Lower Extremity Functional Scale in Patients With Lower Extremity Musculoskeletal Injuries

Abstract

Background:

Purpose:

Study Design:

Methods:

Results:

Conclusion:

Keywords

Methods

Results

Discussion

Conclusion

Authors

Footnotes

ORCID iD

References