
==== Front
Int J Sports Phys Ther
Int J Sports Phys Ther
2159
International Journal of Sports Physical Therapy
2159-2896
NASMI Website: International Journal of Sports Physical Therapy

35391866
33066
10.26603/001c.33066
Original Research
Intra-rater Reliability of a Qualitative Landing Scale for the Single-Hop Test: A Pilot Study
Measson Maxime V. 1
Ithurburn Matthew P. 2
https://orcid.org/0000-0001-7194-7777
Rambaud Alexandre JM. 3
1 Externat Saint Michel, Institut de Formation en Masso-Kinésithérapie de Saint Etienne, Saint Etienne, France
2 Department of Physical Therapy and Center for Exercise Medicine University of Alabama at Birmingham, Birmingham, AL, USA
3 Externat Saint Michel, Institut de Formation en Masso-Kinésithérapie de Saint Etienne; Department of Clinical and Exercise Physiology, Sports Medicine Unity, University Hospital of Saint Etienne, Faculty of Medicine; SFMKS Lab, Société Française des Masseurs-kinésithérapeutes du Sport
Corresponding author: Alexandre J.M. Rambaud Department of Clinical and Exercise Physiology, Sports Medicine Unity, University Hospital of Saint Etienne, Faculty of Medicine, Saint-Etienne, France alexandre.rambaud@chu-st-etienne.fr
1 4 2022
2022
17 3 493500
27 4 2021
23 1 2022
© The Author(s)
https://creativecommons.org/licenses/by-nc/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (4.0) which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

Background

The test battery classically used for return-to-sport (RTS) decision-making after anterior cruciate ligament (ACL) reconstruction (ACLR) may not be sufficient, as it does not include a qualitative analysis of movement. Therefore, the Landing Error Scoring System (LESS) scale was adapted to a primary functional test in the typical RTS test battery: the single leg hop for distance (SHD).

Hypothesis/ Purpose

The aim of this study was to determine the intra-rater reliability of the LESS scale adapted to the SHD (SHD-LESS scale) in healthy young athletes.

Study Design

Reliability analysis

Methods

Nineteen healthy individuals (14 men, 5 women; mean age: 22.4 years) participated in the study. Participants performed the SHD tasks on both limbs (dominant and non-dominant) using a standardized protocol in two sessions that were one week apart (single reviewer; 2-dimensional video). Intra-class correlation coefficients (ICC2,1) were used to measure the reproducibility of the scale in the dominant (dom) and non-dominant (nondom) limbs. Additionally, limb data (dom and nondom) were pooled and evaluated collectively with intra-class correlation coefficients. The Kappa coefficient was used to assess the reproducibility of each individual item of SHD-LESS scale.

Results

The intra-rater reliability was good (ICCdom = 0.77; ICCnondom = 0.87; ICCpooled = 0.87) for the overall SHD-LESS scale scores. Agreement of SHD-LESS individual items ranged from 62% to 100%. Dorsiflexion at initial contact (97% agreement; kappa value=0.79) and knee valgus after landing (88% agreement; kappa value=0.65) had excellent agreement and kappa values.

Conclusion

The newly-adapted SHD-LESS scale showed good intra-rater reliability overall. Further studies should evaluate the impact of using the SHD-LESS scale within the RTS test battery on outcomes in patients after ACLR.

Level of Evidence

3

movement quality
landing error scoring system
hop tests
return to sport
==== Body
pmcINTRODUCTION

After an anterior cruciate ligament (ACL) injury, the aim of ACL reconstruction is to restore functional stability of the knee. Following surgery, a primary end goal of rehabilitation is to prepare the patient to resume sports-related activities, defined in a recent consensus statement on return-to-sport (RTS) as being a part of a continuum: return-to-participation, return-to-sport, and return-to-performance.1 During late-stage rehabilitation, sport-specific tasks such as pivoting and rapid change of directions are typically resumed. To start the transition toward RTS at the completion of rehabilitation, clinical practice guidelines recommend that athletes complete a RTS testing battery in order to evaluate readiness for the return to the field without restriction and with the lowest possible risk of reinjury.2 However, recent meta-analysis data demonstrated that the ACL reinjury rate (ipsilateral and contralateral) in athletes under 25 years of age following RTS was 23%,3 suggesting that currently-used RTS testing may not be comprehensive and may be insufficient to identify those at risk of poor outcomes or reinjury. While RTS testing batteries often include measures of muscle strength and knee-related functional performance, such as one-leg hop for distance tests,2 a key measure missing from most testing batteries used in RTS decision-making is the assessment of movement patterns or movement quality.4

One-leg hop for distance tests, such as the single leg hop for distance (SHD), are the most commonly-used lower limb functional tests after ACLR.5 The SHD remains the most used test because it is simple and does not require any equipment. In addition, the SHD allows for the evaluation of the ability of the knee to absorb load during landing.6 The Limb symmetry Index of SHD, a ratio of the performance of the operated limb to the healthy limb, is widely used in return to sport test batteries.2 But SHD performance/distance symmetry analysis (LSI of SHD) has previously been questioned due to the potential risk of masking information about poor or altered movement strategies to achieve symmetric distance.7,8 For this reason, we sought to combine the objective measurement of distance with a qualitative analysis of landing.

The Landing Error Scoring System (LESS) was originally developed for a double-leg landing task by Padua and colleagues,9 and has a good interrater and intra-rater reliability (.95 and .96 respectively).10 Recent work by O’Connor11 has adapted this scale for a single-leg drop-landing task. However, in the scientific literature, no previous work has utilized a quality of movement scoring system with the most commonly performed functional performance task in the RTS test battery: the SHD.12 Additionally, because the SHD assesses unilateral characteristics of the lower limb, its use as the functional task of interest may be better suited for an assessment of movement quality in those with unilateral injuries compared to a bilateral jump-landing-rebound task (such as the original LESS).11 The aim of this study was to evaluate the intra-rater reliability of the LESS adapted to the SHD (SHD-LESS) in healthy young athletes. The hypothesis of this study was that the reproducibility of the SHD-LESS would be good or excellent (ICC > 0.75).

METHODS

Study Design

This study was an intra-rater reliability study and followed the “Guidelines for Reporting Reliability and Agreement Studies” (GRRAS) and “Quality Appraisal of Reliability Studies” (QAREL)13,14 during the planning and implementation of this study. Prior to the study, a declaration of conformity for the protection of data has been made (MR4 - 2214186v0) to CNIL (Commission Nationale de l’Informatique et des Libertés). All subjects signed written informed consent prior to participating in any study-related procedures.

Participants

Nineteen healthy young individuals (14 men and 5 women; age: 22.4 ± 0.25 years; height: 175.0 ± 1.5 cm; weight: 68.2 ± 2.0 kg) were recruited between February and May 2019 and participated in the study. The inclusion criteria specified that participants were non-professional athletes, participated in a cutting/pivoting sport (soccer, basketball, handball, rugby, budo…) with a minimum frequency of two training sessions/week and one match or game/week, and were between 18 and 25 years old. All participants were enrolled and tested during their sports season. Exclusion criteria were a history of knee injury (ACL or other ligaments of the knee joint) or a history of lower limb musculoskeletal injury less than three months prior to enrollment and testing.

Testing Procedures

Participants completed the SHD task (Figure 1) in two sessions separated by six to 10 days. The general protocol consisted of four consistent steps: 1) introduction to the testing session and tasks, 2) warm-up, 3) test set-up, and 4) task performance and data collection. Following a standardized warm-up program,15 study participants were shown a video demonstration of the correct SHD technique with the following instructions: 1) begin standing on a lower limb behind the start line with arms crossed over the chest; 2) attempt to jump as far forward as possible; and 3) land on the same lower limb while keeping the arms crossed to avoid upper extremity momentum assisting in jump performance (described previously16). Participants were informed that the test would be invalidated if they lost balance (inability to maintain balance upon jump landing for at least 3 seconds) or could not control the landing. Participants were then allowed to ask questions to clarify their understanding of what was required in order to correctly perform the SHD and were provided three practice trials. Following practice trials, participants performed three trials on both the dominant limb and the non-dominant limb, as described by Reid et al.17 The dominant limb was defined as “the primary foot used to kick a ball”.

83598 Figure 1. Single leg hop for distance (SHD) task and 2D camera configuration.

SHD-LESS scale

An adapted LESS scale was created to evaluate the SHD landing: the SHD-LESS scale (Table 1). The adapted SHD-LESS scale was developed using the same procedures as the single-leg drop-landing LESS scale recently described by O’Connor.11 All items on the O’Connor LESS scale for falling and landing on one leg were analyzed for their applicability to the SHD assessment. As a result of this analysis, the items (items 1, 2, 3, 8 and 9) were modified to be relevant to the SHD task (Table 1).

83599 Table 1. Single leg hop for distance – landing error scoring system (SHD-LESS) scale.

		Score	
Sagittal View	1. Forward Trunk Flexion at IC
Error: flexion < 5°.	Yes = 0
No = 1	 	
2. Knee Flexion at IC
Error: flexion <5°.	Yes = 0
No = 1	 	
3. Ankle Dorsiflexion at IC
Error: the landing is not done with the heel.	Yes = 0
No = 1	 	
4. Forward Trunk Flexion Displacement
Error: Trunk DOES NOT flex more than at IC	Yes = 0
No = 1	 	
5. Knee Flexion Displacement
Error: <30° more flexion after IC; F(IC)-F(displacement).	Yes = 0
No = 1	 	
6. Ankle Dorsiflexion Displacement
Error: Heel DOES NOT touch the ground	Yes = 0
No = 1	 	
Frontal View	7. Knee Valgus at IC
Error: the vertical line passing through the center of the patella is medial to or passes through the big toe.	Yes = 2
No = 0	 	
8. Lateral Trunk Flexion at IC
Error: the trunk is tilted by more than 10°.	Yes = 1
No = 0	 	
9. Knee Valgus Displacement
A. Error: the vertical line through the big toe is outside/lateral or on the axis of the patella on the key frame.
If not,
B. Error: the vertical line through the big toe is outside or on the axis of the patella among all images between the IC and after displacement.	Yes = 2
No = 0
if not,
Yes = 1
No = 0	 	
10. Contralateral Pelvic Drop Displacement
Error: Contralateral pelvic drops below ipsilateral pelvic.	Yes = 1
No = 0	 	
11. Tibial Rotation Displacement
Error: there is tibial rotation (more than 2°, included).	Yes = 1
No = 0	 	
Others	12. Distance covered > 64% height
Error: the distance is less than 64% of the subject size.	Yes = 0
No = 1	 	
13. Overall impression
Error if the movement performed by the subject is "rigid/poor" at the hip, knee and ipsilateral ankle.	Excellent=0
Average=1
Poor=2	 	
OVERALL SCORE (0-16)		
IC: initial contact; Displacement: Maximal flexion knee

In addition, two items have been added to the SHD-LESS. The first item added (item 12; Table 1) included an evaluation of the jump performance (distance, cm). In completing the SHD, participants were instructed to jump as far as possible, and this external focus allowed participants to concentrate on the jumping performance and not the explicit execution of the movement/landing. Because it was possible that participants could purposefully jump a shorter distance to improve the overall landing movement quality which might affect the results,18 the jump distance criterion was defined as a minimum distance equal to 64% of the participant’s height.19 If the participant was unable to achieve this distance, a penalty of one point was imposed (Table 1). The second item added (item 13; Table 1) included an overall impression of movement quality during the SHD landing. This item is the same as that of item 16 of the original double-leg landing LESS described by Padua and colleagues.9 Overall landing quality were evaluated as excellent (0 points), average (1 point), or poor (2 points).

Two-dimensional video analysis

As described by Everard et al., two cameras were used to film the jumps from the front and the side.10 Prior to completing the video evaluation and scoring, each SHD test video was verified to include the necessary scoring information (angles, distances, and key images). The cameras were placed on a tripod perpendicular to the frontal and sagittal plane, at a height of 60 cm and a distance of 3m (Figure 1). The video recordings were analyzed using Kinovea (Kinovea, www.kinovea.org, version 0.8.15).

Markers were placed on the great trochanter, the lateral epicondyle of the knee, the lateral malleolus, the center of the patella (estimation of the center of the knee; equidistant from the epicondyles of the femur), and the center of the line passing through the two malleoli (estimation of the center of the ankle joint).

The video evaluations were scored by a single rater (AR; physiotherapist with 20 years of experience). After collecting all data, analyses were performed first for Session 1 and then Session 2, consecutively. The video evaluation to score the SHD-LESS was completed in two parts. First, the evaluation of the jumping performance (item 12; distance) was performed, and this defined the trial that would be evaluated for qualitative performance (the trial with the furthest distance among the 3 trials). Using this trial, the remaining items from the SHD-LESS were scored (items 1-11; 13).

Statistical Analysis

In order to determine intra-rater reliability of the scale, the overall score of the SHD-LESS was compared between Session 1 and Session 2 individually for each lower limb (dominant and non-dominant) using intraclass correlation coefficients (ICC2,1) with statistical adapted tests to the distribution of variables (Pearson test or Spearman test). Following research by Van Melick and al.,20 the dominant and non-dominant limbs were pooled and evaluated between Session 1 and Session 2. ICC2,1 values were interpreted as poor (<0.50), moderate (0.50-0.74), good (0.75-0.89), or excellent (0.90-1.00), according to Portney and Watkins.21

SHD distance was compared between Sessions 1 and 2 with statistical adapted tests to the distribution of variables (paired simple t test or Wilcoxon test). Statistical significance was set at p < 0.05. To determine intra-rater reliability of each individual item of the SHD-LESS scale, kappa coefficients were calculated. The kappa-values were interpreted as follows values ≤ 0 as indicating no agreement and 0.01–0.20 as very poor agreement, 0.21–0.40 as poor agreement, 0.41– 0.60 as moderate agreement, 0.61–0.80 as strong agreement, and 0.81–1.00 as near perfect agreement and =1, perfect agreement.22 Statistical analyses were performed using JASP (JASP Team [2018] Version 0.9.2.0) and R software (version 3.4.4 [2018–03–15]).

RESULTS

The final sample included 17 participants that completed the SHD. Two outliers were excluded from analyses for the SHD test (SHD performance/distance difference between Sessions 1 and 2 >2.5 SD). For the overall SHD-LESS scale scores, intra-rater reliability ICC values were between 0.77 and 0.87 (Table 2).

83600 Table 2. Intra-rater reliability of qualitative (Landing Error Scoring System scale adapted to the single leg hop for distance (SHD): SHD-LESS score) and quantitative (jump distance) measures between sessions 1 and 2. Data are shown as ICC value (95% confidence interval); ICC: intraclass correlation coefficient; dom: dominant lower limb; nondom: non-dominant lower limb.

	Qualitative: Quality of landing score
Test: SHD (SHD-LESS score)	Quantitative: Jump Performance
Test: SHD (jump distance)	
ICCdom	0.77 (0.46 - 0.91)	0.90 (0.73 - 0.96)	
ICCnondom	0.87 (0.67 - 0.95)	0.94 (0.83 - 0.98)	
ICCpooled	0.87 (0.75 - 0.93)	0.92 (0.85 - 0.96)	

For individual items within the SHD-LESS scale, kappa coefficients ranged from very low to almost perfect, depending on the individual item evaluated (Table 3). For jumping performance (quantitative measure), intra-rater reliability of jumping performance ranged from 0.90 to 0.94, depending on the lower limb (dominant vs. non-dominant vs. pooled) (Table 3). No statistical differences were found between Sessions 1 and 2 for the of quality of landing scores (pdom=0.41 ; pnondom=0.07 ; ppooled=0.05) or for SHD jump distance (pdom=0.55 ; pnondom=0.53 ; ppooled=0.73).

83601 Table 3. Percent agreement and Kappa coefficients for SHD-LESS (Landing Error Scoring System scale adapted to the single leg hop for distance) individual items.

		SHD-LESS	
Items	Item description	% Agreement	Kappa value	Interpretation	
1	Forward Trunk Flexion at IC
(degrees)	94%	NC	NC	
2	Knee Flexion at IC
(degrees)	100%	NC	NC	
3	Dorsiflexion at IC
(position)	97%	0.79	Strong	
4	Forward Trunk Flexion Displacement
(degrees)	79%	0.34	Poor	
5	Knee Flexion after Landing
(degrees)	97%	0.00	Very poor	
6	Ankle Dorsiflexion after Landing
(position)	71%	0.12	Very poor	
7	Knee Valgus at IC
(position)	88%	- 0.06	Disagreement	
8	Lateral Trunk Flexion at IC
(degrees)	71%	0.30	Poor	
9	Knee Valgus after Landing
(position)	88%	0.65	Strong	
10	Contralateral Pelvic Drop after Landing
(position)	65%	0.02	Very poor	
11	Tibial Rotation Displacement
(degrees)	62%	0.24	Poor	
12	Distance Covered > 64% Height
(Distance)	97%	0.84	Almost perfect	
13	General observation	76%	0.42	Moderate	
IC: Initial Contact.

DISCUSSION

Main Results (Overall SHD-LESS scores)

The aim of this study was to determine the intra-rater reliability of using an adapted version of the LESS scale for a new task, the SHD. For the overall scores on the SHD-LESS scale, we found good intra-rater reliability (ICC=0.77 and ICC=0.87 for the dominant and non-dominant limb, respectively).21 Regarding the reproducibility of this newly-developed SHD-LESS scale, there are no previous studies with which to compare our results. In addition, we observed differences in ICC values between the dominant and non-dominant lower limbs. The dominant limb was defined as the primary foot used to kick a ball. However, unilateral tasks were evaluated in the current study, and it may have not been necessary to differentiate dominant and non-dominant limbs. The data could have been pooled initially.20 When analyzing the pooled data, good intra-rater reliability was found (ICCpooled = 0.87), utilizing a larger sample size (17 subjects with 2 legs; n=34).

Secondary Outcomes (Individual Item Analyses)

In this study, percentage of agreement for individual SHD-LESS items ranged from 62% to 100%. For tibial rotation (item 11), the rater (AR) of the study achieved only 62% agreement. Because tibial rotation is a transverse plane variable, it is likely that evaluating this item may be particularly difficult with cameras only in the sagittal and frontal planes, and may be inappropriate for a 2D assessment of movement. In calculating percent agreement values, Cohen suggests the possibility that there is the potential for false agreement when raters make random guesses, and Cohen’s kappa was developed to account for this concern.23 For individual item assessment of the SHD-LESS, the Kappa coefficients ranged from very poor to almost perfect for both scales. While overall scores for the SHD-LESS demonstrated good reliability, only three items (dorsiflexion of the ankle, knee flexion displacement, and knee valgus displacement) showed Kappa values interpreted as strong on the 13 items for this scale. Interpretation of the Kappa scores for some items does not seem possible, because no errors were found in the video analyses for some items (not allowing for calculation of the Kappa score). These items may have less relevance for a healthy population, but could be of great relevance for individuals following ACL reconstruction.24,25 Thus, future studies should evaluate the reliability (overall and individual item assessment) of the SHD-LESS in patients following ACL reconstruction.

To ensure that subjects performed a reasonably similar task between the two sessions, jumping performance on the SHD (quantified as hop distance) has been investigated and an excellent agreement for jump performance (distance; item 12; Table 2) on the SHD task has been obtained. These findings are consistent with previous work examining the reliability of the SHD for jump performance (distance), which found excellent reliability (ICC=0.92).17 While the jump distances between the two sessions were highly correlated, recent research has shown that individuals following ACL reconstruction with similar distance performance on the SHD and other dynamic tasks use varying movement strategies to accomplish the tasks.26,27 Thus, the landing movement strategies used with similar distance jumps between the 2 trials could not be really identical, which may affect the reliability of the qualitative landing assessment.26,27

Further applications

The overall scores for the SHD-LESS scale demonstrated good reliability and may be an important component in future ACL reconstruction RTS testing batteries. The SHD-LESS scale contributes to an objective RTS evaluation, with an analysis of the quality of landing during the test most frequently used in the decision to RTS (i.e., the SHD).12 The SHD may also be the most relevant sport-related task to evaluate for quality of movement in individuals following ACLR. Specifically, unilateral tasks may be more relevant than bilateral tasks for qualitative assessment, because of the possibility of compensation on the healthy lower limb during a bilateral landing task like the drop vertical jump (DVJ).28 Additionally, the single-leg hop tests described originally by Noyes et al.29 have been used extensively and previously evaluated for intra- and inter-rater reproducibility.17,30 These functional tests therefore provide clinicians with important information in the follow-up and serial testing of their ACLR patients.

The single-leg drop landing task is also incorporated in RTS testing batteries following ACL reconstruction,31 and is associated with other important elements such as psychological factors and social-contextual factors.32 Also, a single-leg drop landing task may be more biomechanically-demanding26 compared to SHD and only appropriate in late-stage rehabilitation. The SHD is often performed earlier in rehabilitation following ACL reconstruction (approximately 3 months) to assist with return to running, and thus may have greater utility during early-to-mid rehabilitation progression.33,34

Single-leg distance jump tests appear to have low sensitivity in predicting injury-free return to sport, but high specificity,35 and providing an objective assessment of the patient’s functional abilities after ACLR. It should be noted that functional tests, although providing valuable information, do not, on their own, indicate how well the patient is recovering from ACLR or how ready for return to sport they are.

Study limitations

The current study, although pilot in nature, is not without important limitations. First, the 2D video analysis time was particularly long to complete the scale scoring for each task (30 minutes for one limb). This may limit the clinical application of these scales in a real-time setting. Secondly, the current study included only a young population (20-25 years old), with more males than females, which does not reflect or apply to the general population. Finally, items of this newly-developed SHD-LESS scale were not previously validated, due to the pilot nature of this study. Future research should refine and validate these individual items for eventual applications in patient populations (such as those post-ACL reconstruction) for which movement quality assessment may be a critical part of a multifactorial functional assessment.

Finally, it would be interesting to evaluate inter-rater reproducibility as well as to establish a cut-off score to reduce the risk of (re)injury, especially after ACL reconstruction.

CONCLUSION

The newly-adapted SHD-LESS scale showed good intra-rater reliability, and could be used alongside the evaluation of SHD performance in RTS testing following ACL reconstruction. Further studies should evaluate the inter and intra-rater reliability of the SHD-LESS in individuals following ACL reconstruction as well as the impact of using the SHD-LESS scale within the RTS test battery on outcomes.

Conflicts of Interest

The authors declare that they have no conflicts of interest.
==== Refs
2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern British Journal of Sports Medicine Ardern Clare L Glasgow Philip Schneiders Anthony Witvrouw Erik Clarsen Benjamin Cools Ann Gojanovic Boris Griffin Steffan Khan Karim M Moksnes Håvard Mutch Stephen A Phillips Nicola Reurink Gustaaf Sadler Robin Grävare Silbernagel Karin Thorborg Kristian Wangensteen Arnlaug Wilk Kevin E Bizzini Mario BMJ 25 5 2016
50 14 853 864 0306-3674 10.1136/bjsports-2016-096278 10.1136/bjsports-2016-096278 27226389
Evidence-based clinical practice update: practice guidelines for anterior cruciate ligament rehabilitation based on a systematic review and multidisciplinary consensus British Journal of Sports Medicine van Melick Nicky van Cingel Robert E H Brooijmans Frans Neeter Camille van Tienen Tony Hullegie Wim Nijhuis-van der Sanden Maria W G 18 8 2016
50 24 1506 1515 0306-3674 10.1136/bjsports-2015-095898 10.1136/bjsports-2015-095898
Risk of secondary injury in younger athletes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis The American Journal of Sports Medicine Wiggins Amelia J. Grandhi Ravi K. Schneider Daniel K. Stanfield Denver Webster Kate E. Myer Gregory D. 15 1 2016
44 7 1861 1876 0363-5465 10.1177/0363546515621554 10.1177/0363546515621554 26772611
Lower limb biomechanics during single-leg landings following anterior cruciate ligament reconstruction: a systematic review and meta-analysis Sports Medicine Johnston Peta T. McClelland Jodie A. Webster Kate E. 12 6 2018
48 9 2103 2126 0112-1642 10.1007/s40279-018-0942-0 10.1007/s40279-018-0942-0
Functional performance testing after anterior cruciate ligament reconstruction: a systematic review Orthopaedic Journal of Sports Medicine Abrams Geoffrey D. Harris Joshua D. Gupta Anil K. McCormick Frank M. Bush-Joseph Charles A. Verma Nikhil N. Cole Brian J. Bach Bernard R. Jr 1 1 2014
2 1 2325967113518305 2325-9671 10.1177/2325967113518305 10.1177/2325967113518305 26535266
Vertical and horizontal hop performance: contributions of the hip, knee, and ankle Sports Health: A Multidisciplinary Approach Kotsifaki Argyro Korakakis Vasileios Graham-Smith Philip Sideris Vasileios Whiteley Rod 9 2 2021
13 2 128 135 1941-7381 10.1177/1941738120976363 10.1177/1941738120976363 33560920
A critical analysis of limb symmetry indices of hop tests in athletes after anterior cruciate ligament reconstruction: A case control study Orthopaedics & Traumatology: Surgery & Research Gokeler A. Welling W. Benjaminse A. Lemmink K. Seil R. Zaffagnini S. 10 2017
103 6 947 951 1877-0568 10.1016/j.otsr.2017.02.015 10.1016/j.otsr.2017.02.015
Variability in leg muscle power and hop performance after anterior cruciate ligament reconstruction Knee Surgery, Sports Traumatology, Arthroscopy Thomeé Roland Neeter Camille Gustavsson Alexander Thomeé Pia Augustsson Jesper Eriksson Bengt Karlsson Jon Springer Science and Business Media LLC 8 2 2012
20 6 1143 1151 0942-2056 10.1007/s00167-012-1912-y 10.1007/s00167-012-1912-y
The Landing Error Scoring System (LESS) is a valid and reliable clinical assessment tool of jump-landing biomechanics: The JUMP-ACL study The American Journal of Sports Medicine Padua Darin A. Marshall Stephen W. Boling Michelle C. Thigpen Charles A. Garrett William E. Jr Beutler Anthony I. SAGE Publications 2 9 2009
37 10 1996 2002 0363-5465 10.1177/0363546509343200 10.1177/0363546509343200
Examining the reliability of the Landing Error Scoring System with raters using the standardized instructions and scoring sheet J Sport Rehabil Everard Eoin Lyons Mark Harrison Andrew J. 1 5 2020
29 4 519 525 1056-6716 10.1123/jsr.2018-0387 10.1123/jsr.2018-0387
The development of the Single-Leg Landing Error Scoring System (SL-LESS) for lower extremity movement screening Theses and Dissertations O’Connor M.L. 2015
1069 https://dc.uwm.edu/etd/1069
Which criteria are used to clear patients to return to sport after primary ACL reconstruction? A scoping review British Journal of Sports Medicine Burgi Ciara R Peters Scott Ardern Clare L Magill John R Gomez Christina D Sylvain Jonathan Reiman Michael P BMJ 2 2 2019
53 18 1154 1161 0306-3674 10.1136/bjsports-2018-099982 10.1136/bjsports-2018-099982
The development of a quality appraisal tool for studies of diagnostic reliability (QAREL) Journal of Clinical Epidemiology Lucas Nicholas P. Macaskill Petra Irwig Les Bogduk Nikolai 8 2010
63 8 854 861 0895-4356 10.1016/j.jclinepi.2009.10.002 10.1016/j.jclinepi.2009.10.002 20056381
Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were proposed Journal of Clinical Epidemiology Kottner Jan Audigé Laurent Brorson Stig Donner Allan Gajewski Byron J. Hróbjartsson Asbjørn Roberts Chris Shoukri Mohamed Streiner David L. 1 2011
64 1 96 106 0895-4356 10.1016/j.jclinepi.2010.03.002 10.1016/j.jclinepi.2010.03.002
Can two-dimensional video analysis during single-leg drop vertical jumps help identify non-contact knee injury risk? a one-year prospective study Clinical Biomechanics Dingenen Bart Malfait Bart Nijs Stefaan Peers Koen H.E. Vereecken Styn Verschueren Sabine M.P. Staes Filip F. 10 2015
30 8 781 787 0268-0033 10.1016/j.clinbiomech.2015.06.013 10.1016/j.clinbiomech.2015.06.013
Criteria for Return to Sport after Anterior Cruciate Ligament reconstruction with lower reinjury risk (CR’STAL study): protocol for a prospective observational study in France BMJ Open Rambaud Alexandre J M Semay Bertrand Samozino Pierre Morin Jean-Benoît Testa Rodolphe Philippot Rémi Rossi Jérémy Edouard Pascal 6 2017
7 6 e015087 2044-6055 10.1136/bmjopen-2016-015087 10.1136/bmjopen-2016-015087 28667211
Hop testing provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction Phys Ther Reid Andrea Birmingham Trevor B Stratford Paul W Alcock Greg K Giffin J Robert 1 3 2007
87 3 337 349 0031-9023 10.2522/ptj.20060143 10.2522/ptj.20060143
Landing Error Scoring System scores change with knowledge of scoring criteria and prior performance Physical Therapy in Sport Hanzlíková Ivana Hébert-Losier Kim 11 2020
46 155 161 1466-853X 10.1016/j.ptsp.2020.09.004 10.1016/j.ptsp.2020.09.004
Preseason functional test scores are associated with future sports injury in female collegiate athletes J Strength Cond Res Brumitt Jason Heiderscheit Bryan C. Manske Robert C. Niemuth Paul E. Mattocks Alma Rauh Mitchell J. 6 2018
32 6 1692 1701 1064-8011 10.1519/jsc.0000000000002243 10.1519/jsc.0000000000002243 28930873
How to determine leg dominance: the agreement between self-reported and observed performance in healthy adults PLoS ONE van Melick Nicky Meddeler Bart M. Hoogeboom Thomas J. Nijhuis-van der Sanden Maria W. G. van Cingel Robert E. H. Macaluso Andrea 29 12 2017
12 12 e0189876 1932-6203 10.1371/journal.pone.0189876 10.1371/journal.pone.0189876 29287067
Validity of Measurements Foundations of Clinical Research: Applications to Practice Portney L.G. Watkins M.P. 2000
2
The measurement of observer agreement for categorical data Biometrics Landis J. Richard Koch Gary G. JSTOR 3 1977
33 1 159 0006-341X 10.2307/2529310 10.2307/2529310 843571
Interrater reliability: the kappa statistic Biochemia Medica McHugh Marry L. 2012
22 3 276 282 1846-7482 10.11613/bm.2012.031 10.11613/bm.2012.031 23092060
Video analysis of anterior cruciate ligament injury: abnormalities in hip and ankle kinematics The American Journal of Sports Medicine Boden Barry P. Torg Joseph S. Knowles Sarah B. Hewett Timothy E. 2 2009
37 2 252 259 0363-5465 10.1177/0363546508328107 10.1177/0363546508328107
Mechanism-based pattern approach to classification of complex injuries of the knee depicted at MR imaging Radiographics Hayes Curtis W. Brigido Monica K. Jamadar David A. Propeck Tim 10 2000
20 Spec No S121 S134 0271-5333 10.1148/radiographics.20.suppl_1.g00oc21s121 10.1148/radiographics.20.suppl_1.g00oc21s121
Back to normal symmetry? Biomechanical variables remain more asymmetrical than normal during jump and change-of-direction testing 9 months after anterior cruciate ligament reconstruction The American Journal of Sports Medicine King Enda Richter Chris Franklyn-Miller Andy Wadey Ross Moran Ray Strike Siobhan SAGE Publications 4 2019
47 5 1175 1185 0363-5465 10.1177/0363546519830656 10.1177/0363546519830656 30943079
Biomechanical but not timed performance asymmetries persist between limbs 9 months after ACL reconstruction during planned and unplanned change of direction Journal of Biomechanics King Enda Richter Chris Franklyn-Miller Andy Daniels Katherine Wadey Ross Jackson Mark Moran Ray Strike Siobhan 11 2018
81 93 103 0021-9290 10.1016/j.jbiomech.2018.09.021 10.1016/j.jbiomech.2018.09.021
Hip biomechanics differ in responders and non-responders to an ACL injury prevention program Knee Surgery, Sports Traumatology, Arthroscopy Taylor Jeffrey B. Nguyen Anh-Dung Shultz Sandra J. Ford Kevin R. Springer Science and Business Media LLC 27 9 2018
28 4 00167 00018 0942-2056 10.1007/s00167-018-5158-1 10.1007/s00167-018-5158-1
Abnormal lower limb symmetry determined by function hop tests after anterior cruciate ligament rupture The American Journal of Sports Medicine Noyes Frank R. Barber Sue D. Mangine Robert E. SAGE Publications 9 1991
19 5 513 518 0363-5465 10.1177/036354659101900518 10.1177/036354659101900518 1962720
Test-retest and interrater reliability of the functional lower extremity evaluation Journal of Orthopaedic & Sports Physical Therapy Haitz Karyn Shultz Rebecca Hodgins Melissa Matheson Gordon O. Journal of Orthopaedic & Sports Physical Therapy (JOSPT) 12 2014
44 12 947 954 0190-6011 10.2519/jospt.2014.4809 10.2519/jospt.2014.4809
Validation of a composite test for assessment of readiness for return to sports after anterior cruciate ligament reconstruction: The K-STARTS Test Sports Health: A Multidisciplinary Approach Blakeney William G. Ouanezar Hervé Rogowski Isabelle Vigne Gregory Guen Meven Le Fayard Jean-Marie Thaunat Mathieu Chambat Pierre Sonnery-Cottet Bertrand SAGE Publications 19 7 2018
10 6 515 522 1941-7381 10.1177/1941738118786454 10.1177/1941738118786454 30024344
What modifying factors can help improve anterior cruciate ligament reconstruction rehabilitation? A narrative review Ann Phys Rehabil Med Rambaud A.J.M. Neri T. Dingenen B..
Criteria for return to running after anterior cruciate ligament reconstruction: a scoping review British Journal of Sports Medicine Rambaud Alexandre J M Ardern Clare L Thoreux Patricia Regnaux Jean-Philippe Edouard Pascal 2 5 2018
52 22 1437 1444 0306-3674 10.1136/bjsports-2017-098602 10.1136/bjsports-2017-098602
Evolution of functional recovery using hop test assessment after ACL reconstruction International Journal of Sports Medicine Rambaud Alexandre J.M. Rossi Jérémy Neri Thomas Samozino Pierre Edouard Pascal 12 5 2020
41 10 696 704 0172-4622 10.1055/a-1122-8995 10.1055/a-1122-8995
Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture British Journal of Sports Medicine Kyritsis Polyvios Bahr Roald Landreau Philippe Miladi Riadh Witvrouw Erik 23 5 2016
50 15 946 U84 0306-3674 10.1136/bjsports-2015-095908 10.1136/bjsports-2015-095908
