High Rate of Overlapping Question Content Among Commonly Used Patient-Reported Outcome Measurements for Anterior Cruciate Ligament Injury.

PURPOSE: To precisely compare the questions and content between the most commonly cited knee-specific patient-reported outcome measurements (PROs) for anterior cruciate ligament (ACL) injury.
METHODS: A literature review through Medline from November 1, 2018, to November 1, 2020, was performed to find the most cited knee-specific PROs for assessment of ACL injuries. Each question was then classified as 1) identical, similar, or unique; 2) pertaining to 1 of 6 domains (pain, symptoms, functional activities, occupational activities, sports/recreation, and quality of life). The PROs were then compared to each other to assess question overlap and domain coverage.
RESULTS: A total of 133 questions were analyzed from the seven most common PROs: International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, Tegner Activity Scale, Marx Scale, Knee Outcome Survey (KOS), and Cincinnati Knee Rating System (CKRS). The total distribution of identical (31.6%), similar (31.6%), and unique (36.8%) questions was found to be relatively even. However, this distribution varied within each PRO. KOS and Lysholm had the highest percentages of identical questions (64% and 62.5%, respectively). KOOS had the highest number of unique questions (26/42, 61.9%), while Tegner held the highest percentage (11/16, 68.8%). Sports/recreation was the only domain assessed by all PROs.
CONCLUSION: Nearly two-thirds of questions overlap between the commonly used PROs for ACL injury. Although sports/recreation is assessed by all PROs, each has its own pattern of coverage across this and other domains. LEVEL OF EVIDENCE: IV, cross-sectional study.

Introduction

Outcome measures are valuable instruments in assessment of injury, surgery, and rehabilitation. A standardized manner of evaluation allows comparisons between patients, treatments, and studies. These comparisons provide further knowledge and enable clinicians to deliver the highest level of evidence-based medicine. However, studies that examine the same disease process often use different patient-reported outcomes (PROs), making comparisons between studies challenging.

In a 2020 consensus meeting that sought to establish a standardized evaluation of ACL treatment, patient-reported outcome (PROs) measures were identified as one of four robust outcome categories; the other three being early adverse events, ACL graft failure/recurrent ligament disruption, and clinical measures of knee function and structure. A 2015 consensus also recognized PROs as part of the criteria for successful outcome following ACL injury or reconstruction. PROs allow patients to give a direct report of their health condition. Previous studies in orthopaedic populations have shown that clinicians, as compared to patients, rate symptoms as less severe and function as better. This discrepancy supports the notion that patient-relevant data should be collected from patients themselves. Clinicians can use these questionnaires to understand what matters most to patients, such as symptoms with daily activities.

Although earlier studies have assessed the validity and applicability of PROs in evaluating patients with ACL injuries,,6, 7, 8 no study has examined exactly how similar these PROs are to each other. Understanding the question content of PROs may allow clinicians and researchers to select the appropriate measurement for a given study or population.

The purpose of this study is to precisely compare the questions and domain coverage between the most commonly cited knee-specific PROs for ACL injury. Our hypothesis is that there is significant overlap (identical or similar questions) between different PROs; however, each PRO may offer a different perspective based on its question composition and focus.

Methods

A literature review was performed through Medline using “anterior cruciate ligament” [title] AND “patient reported outcome∗” from November 1, 2018, to November 1, 2020. This literature search was limited to the preceding 2 years in an effort to capture the most current usage. Duplicate studies and those that did not mention a specific PRO were excluded. From the remaining studies, the most frequently used knee-specific PROs were determined.

Questions from each PRO were then analyzed. Each question was first classified as “identical,” “similar,” or “unique.” A question that was repeated in another PRO was labeled “identical.” A question that imprecisely asked about the same activity or symptom was labeled “similar.” A question that did not appear in another PRO was labeled “unique.” The classification for each question was agreed upon by all authors. PROs were then compared to each other to determine the amount of overlap (identical and similar questions) and uniqueness.

Next, in reviewing the content of all questions, it was determined that each question could be characterized as pertaining to one of six domains: pain, symptoms, functional activities, sports/recreation, quality of life, and occupational. Again, the domain classification for each question was agreed upon by all authors. Each PRO was then assessed for the degree of coverage across the various domains.

Results

PRO Questionnaires

As depicted in Fig 1, literature review of ACL studies involving PROs within the preceding 2 years yielded 126 studies. Six studies did not identify a specific PRO. One study was copublished in more than one journal. Of the remaining 119 studies, the most commonly used knee-specific PROs were the International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, Tegner Activity Scale, Marx Scale, Knee Outcome Survey (KOS), and Cincinnati Knee Rating System (CKRS) (Appendix 1).

Fig 1

Selection of studies.

The most frequently used PRO, found in 83 studies (69.7%), was the IKDC form. The IKDC was formed in 1987 by a group of clinicians who felt there was a need for a standardized method to quantify the disability caused by knee ligament injuries and the results of treatment. The IKDC Knee Ligament Standard Evaluation Form was subsequently published in 1993. In 1997, the American Orthopaedic Society for Sports Medicine (AOSSM) moved to revise the form to broaden its application, including ligament and meniscal injuries, articular cartilage lesions, arthritis, and patellofemoral conditions. The resultant IKDC Subjective Knee Form was published in 2001 and has 19 questions divided in three sections: 1) symptoms, including pain, stiffness, swelling, locking/catching, and giving way; 2) sports and daily activities; and 3) current knee function and knee function prior to knee injury.

The next most common PRO was the KOOS, cited in 72 studies (60.5%). The KOOS was published in 1998 as an instrument to assess young and middle-aged patients with ACL injury, meniscus injury, or post-traumatic osteoarthritis. The creators of KOOS emphasized “patient-relevant outcomes,” covering five dimensions: pain, symptoms, activities of daily living, sport and recreation function, and knee-related quality of life. Among the 42 questions is the Western Ontario and MacMaster Universities (WOMAC) Osteoarthritis Index, widely used in the evaluation of patients with hip and knee osteoarthritis.,

The Lysholm and Tegner forms appeared in 52 (43.7%) and 44 (37%) studies, respectively. The Lysholm Knee Scoring Scale was originally published in 1982 to evaluate outcomes of knee ligament surgery, particularly symptoms of instability. The scale was revised in 1985, at the same time that the Tegner Activity Score was introduced. The Tegner score was intended for use in conjunction with the Lysholm. The Lysholm scale asks about 8 items: limp, support, locking, instability, pain, swelling, stair-climbing, and squatting. To complement this, the Tegner scale consists of a graduated list of sports/recreation, functional, and occupational activities. The patient selects the option that best describes their activity level at a given time point (i.e., current level, before injury or following surgery).

On the 11-item Tegner Activity Scale, there was occasionally more than one domain asked in a single query. For example, one item combined “sedentary work” (occupational) and “walking on even ground” (functional activities). The decision was made to treat these combined items separately, yielding instead a total of 16 questions for analysis.

The more recently created (2001) Marx scale was used in 13 studies (10.9%). The goal of the Marx scale is to provide information on a patient’s baseline level of activity. Its authors explained that a patient’s activity level must be taken into account when evaluating their outcome. Namely, active patients will have different expectations and demands than patients who are relatively sedentary. The questionnaire was purposely designed with the goal that it could be completed in 1 minute, so as to allow use with other instruments. With this focus, the Marx scale asks about four activities: running, cutting, deceleration, and pivoting. By choosing not to base questions on specific sports, authors are able to compare patients across different activities. The Marx scale distinguishes itself from the Tegner Activity Score by evaluating both the type of activity and the amount of participation time.

Nine studies (7.6%) employed the KOS. Its 1998 publication explains that the questionnaire was developed from existing instruments, including the CKRS, Lysholm, WOMAC, and IKDC. The KOS consists of 25 questions within two scales: the Activities of Daily Living Scale (KOS-ADLS) and the Sports Activity Scale (KOS-SAS). The questions address symptoms and functional limitations experienced during activities of daily living and sports activities.

Finally, the CKRS was used in 8 studies (6.7%) and consisted of 19 questions. Its first version, published in 1983, focused on knee function in athletic participation., It has been subsequently revised with additional scales and modifications for occupational activities, athletic activities, symptoms, and functional limitations with sports and daily activities.,

PRO Question Analysis of Overlap

Seven PROs, with a total of 133 questions, were evaluated (Table 1). The KOOS had the highest number of questions (42), with the KOS second (25). The Marx contained the fewest number of questions (4). The aggregate distribution of identical, similar, and unique questions was found to be 31.6% (42 questions), 31.6% (42 questions), and 36.8% (49 questions), respectively. Table 2 lists identical questions, and Table 3 lists unique questions. Despite this relatively even distribution across all gathered questions, the distribution for each individual PRO differed from one another (Fig 2). The KOOS had the highest number of unique questions (26/42, 61.9%), while Tegner held the highest percentage (11/16, 68.8%). The KOS, which was developed from four of the other PROs (the CKRS, Lysholm, WOMAC, and IKDC), was found to have the highest percentage of identical questions (16/25, 64%). Aside from Marx, the KOS also had the lowest percentage of unique questions (2/25, 8%). All four questions in the Marx scale were similar to those in other PRO scales.

Table 1

The most common knee-specific PROs cited in studies pertaining to ACL injury between November 1, 2018, and November 1, 2020

	Percent of Studies	Publication Date	Domains	Number of Questions
IKDC	69.7%	2001	Pain, symptoms, functional activities, sports/recreation	19
KOOS	60.5%	1998	Pain, symptoms, functional activities, sports/recreation, quality of life	42
Lysholm	43.7%	1982	Pain, symptoms, functional activities	8
Tegner	37.0%	1985	Functional activities, sports/recreation, occupational	11
Marx	10.9%	2001	Sports/recreation	4
KOS	7.6%	1998	Pain, symptoms, functional activities, sports/recreation	25
CKRS	6.7%	1983	Pain, symptoms, functional activities, sports/recreation, occupational	19

ACL, anterior cruciate ligament; CKRS, Cincinnati Knee Rating System; IKDC, International Knee Documentation Committee; KOOS, Knee Injury and Osteoarthritis Outcome Score; KOS, Knee Outcome Survey; PROs, patient-reported outcomes.

Table 2

Identical Questions

Domain	Question	IKDC	KOOS	Lysholm	Tegner	Marx	KOS	Cincinnati
Pain	Pain			+			+	+
Symptom	Swelling		+	+			+	+
	Limping			+			+
	(Slipping or) Partial giving way						+	+
	(Buckling or) Full giving way						+	+
Functional activities	Go upstairs (ascending)	+	+				+
	Go down stairs (descending)	+	+				+
	Stairs			+				+
	Kneel on the front of your knee	+					+
	Squatting	+		+			+
	Sit with your knee bent	+					+
	Rise from a chair	+					+
	Standing		+				+
	Walking						+	+
Sports/recreation	Running straight	+					+	+
	Jump and land on involved/affected leg	+					+	+
	Stop and start quickly	+					+

IKDC, International Knee Documentation Committee; KOOS, Knee Injury and Osteoarthritis Outcome Score; KOS, Knee Outcome Survey.

Table 3

Unique Questions

	Domain	Question
IKDC	Pain	What is the highest level of activity that you can perform without significant knee pain?
	Symptoms	What is the highest level of activity you can perform without significant swelling in your knee?
	Functional Activities	Function prior to your knee injury
KOOS	Pain	Twisting/pivoting on your knee
		Straightening knee fully
		Bending knee fully
		Walking on flat surface
		Going up or down stairs
		At night while in bed
		Sitting or lying
		Standing upright
	Symptoms	Can you straighten your knee fully?
		Can you bend your knee fully?
	Functional activities	Bending to floor/pick up an object
		Getting in/out of car
		Going shopping
		Putting on socks/stockings
		Rising from bed
		Talking off socks/stockings
		Lying in bed (turning over, maintaining knee position)
		Getting in/out of bath
		Getting on/off toilet
		Light domestic duties (cooking, dusting, etc.)
	Sports/recreation	Squatting
		Kneeling
	Quality of life	How often are you aware of your knee problem?
		Have you modified your life style to avoid potentially damaging activities to your knee?
		How much are you troubled with lack of confidence in your knee?
		In general, how much difficulty do you have with your knee?
Lysholm	Symptoms	Support (“Using cane or crutches”)
Tegner	Sports/recreation	Soccer: national and international elite
		Soccer, lower divisions; ice hockey; wrestling; gymnastics
		Tennis and badminton; handball; basketball; downhill skiing; jogging, at least 5 times per week
		Competitive sports (cycling, cross-country skiing) or recreational sports (jogging on uneven ground at least twice per week)
		Recreational sports (cycling, cross-country skiing, jogging on even ground at least twice weekly)
		Competitive and recreational sports (swimming) or walking in forest possible
	Occupational	Work (heavy labor [e.g., building, forestry])
		Work (light labor [e.g., nursing])
		Work (light labor)
		Work (sedentary work)
		Sick leave or disability pension because of knee problems
KOS	Symptoms	Weakness
Cincinnati	Occupational	Sitting
		Standing / walking
		Squatting
		Climbing
		Lifting / carrying
		Pounds carried

IKDC, International Knee Documentation Committee; KOOS, Knee Injury and Osteoarthritis Outcome Score; KOS, Knee Outcome Survey.

Fig 2

Distributions of overlapping (identical and similar) and unique questions for each patient-reported outcome (PRO) measurement: International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, Tegner Activity Scale, Marx Scale, Knee Outcome Survey (KOS), and Cincinnati Knee Rating System (CKRS).

Table 4 lists the most commonly asked questions. Questions about stiffness/swelling, stairs, running, and jumping were included in 5 of the 7 PROs. There was no single question that was included in every PRO. The percentages of both identical and similar questions between different pairs of PROs are shown in Fig 3. All 4 (100%) Marx questions overlapped with the KOS and 3 (75%) questions overlapped with the CKRS. The Lysholm overlapped 75% (6/8) with both the IKDC and KOS. The Lysholm and Tegner, made to complement one another, did not overlap at all. Neither overlapped with the Marx scale as well.

Table 4

Most Commonly Asked Questions

Domain	Question Stem	Percent of PROs	IKDC	KOOS	Lysholm	Tegner	Marx	KOS	Cincinnati
Symptom	Stiffness/Swelling	71.4% (5/7)	+	+	+			+	+
Functional activity	Stairs		+	+	+			+	+
Sports/recreation	Running		+	+			+	+	+
	Jumping		+	+		+		+	+
Pain	Pain Severity	57.1% (4/7)	+		+			+	+
Symptom	Giving way		+		+			+	+
Functional activity	Squatting		+		+			+	+
	Walking			+		+		+	+
Sports/recreation	Pivoting			+			+	+	+
Symptom	Lock/catch	42.9% (3/7)	+	+	+
Functional activity	Kneeling		+					+	+
	Sitting		+	+				+
	Rising		+	+				+
Sports/recreation	Stopping/starting		+				+	+
	Cutting						+	+	+

Fig 3

Percentage of overlapping questions between pairs of patient-reported outcome (PROs) measurements for the International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, Tegner Activity Scale, Marx Scale, Knee Outcome Survey (KOS), and Cincinnati Knee Rating System (CKRS). The row for each PRO lists the percentage of its total questions that are identical or similar to those of another PRO (column). The denominator for the percentage of overlap is based on the total number of questions for the PRO in that row (indicated by n). Red color indicates a higher percentage of overlap. Green color indicates a lower percentage of overlap.

PRO Question Analysis of Domain Coverage

Fig 4 illustrates each PRO’s coverage across different domains. No single PRO assessed all 6 domains of patient outcomes. Instead, each PRO had a distinct question composition that varied across the different domains. The CKRS and KOOS evaluated all domains except Quality of Life and Occupational, respectively. The KOS and IKDC evaluated 4/6 domains, while the Lysholm and Tegner evaluated 3/6. Sports/Recreation was the only domain assessed by all PROs. With the exception of Marx, which only assessed Sports/Recreation, Functional Activities was evaluated in all PROs. The KOOS was the only PRO that evaluated Quality of Life.

Fig 4

Percentage of question distribution by domain across each patient-reported outcome (PRO) measurement for the International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, Tegner Activity Scale, Marx Scale, Knee Outcome Survey (KOS), and Cincinnati Knee Rating System (CKRS).

Discussion

There is notable overlap among commonly used patient-administered questionnaires in evaluation of ACL injuries. Within the seven PROs examined in this study, 62.4% (84 of 133 questions) of questions were found to be identical or similar. This amount of overlap can be reassuring when attempting to compare studies that employ different PROs. Each PRO, however, is distinguished by its pattern of domain coverage. Understanding the strengths and limitations of available PROs will help guide clinicians in selecting the appropriate surveys for their desired goals.

The IKDC and KOOS are the most commonly used today, cited in 69.7% and 60.5%, respectively, of ACL studies over the past 2 years. Most of the questions asked in the IKDC were found to be identical (47.4%) or similar (36.8%) to another PRO. The KOOS displayed an opposite distribution: 61.9% of its questions were unique, while only 9.5% were identical. Incorporated questions from the WOMAC, commonly used for hip and knee osteoarthritis patients, were a large contributor to this uniqueness. Importantly, despite the KOOS covering 5/6 domains and the greatest number of questions among this selection of PROs, it does not include specific items related to instability. This notable absence suggests that KOOS may be more appropriately applied for general knee health.

A 2015 study looked at the various objective and subjective outcomes presented in studies related to ACL reconstruction in four high-impact-factor orthopaedic journals from 2010 through 2014. Authors similarly found that the IKDC was the most prevalent PRO used, found in 71.4% of those studies. The Lysholm and Tegner followed with 63% and 42%, respectively. Interestingly, the KOOS was found to be the fourth most common PRO. Notably, when compared to the preceding 5-year period (2005 through 2009), the KOOS showed the largest increase in usage from 8% to 20%. It is possible that with greater appreciation of patient well-being, the use of KOOS has continued to increase with time. As patient satisfaction draws more attention with increasing clinical and economic implications, the Quality of Life section of KOOS may be seen as a meaningful advantage.

In the same 2015 review on ACL studies in high-impact factor orthopaedic journals, it was found that most studies reported either two (41%) or three (33%) PROs. The 2020 consensus statement agrees with this practice of applying more than one outcome measurement in evaluation of ACL treatment. Specifically, the consensus recommends the use of at least one knee-specific tool, one health-related quality-of-life tool, and one activity rating scale. The IKDC Subjective Knee Form is the endorsed knee-specific tool, agreed upon by nearly all (24/25) consensus members. However, the authors add that despite the IKDC being “currently the optimal scale, … we should be careful not to neglect the other scores.” For sports and activity assessment, the consensus recommends the Marx scale. The consensus statement did not recommend a particular health-related quality of life measure. However, among their list of possible options, the KOOS is the only PRO analyzed in this study that fulfills the role. The impact of ACL injury on the patient’s overall well-being should not be overlooked. The KOOS validation study showed that the quality of life subscale had the highest effect size at 6 months postoperatively for patients who underwent ACL reconstruction. It is notable that this domain only makes up 9.5% (4 questions) of the questionnaire.

There are other measures that could instead serve as a health-related quality of life measure, including Quality of Life Outcome Measure for Chronic Anterior Cruciate Ligament Deficiency (ACL-QOL), European Quality of Life-5 dimensions (EQ-5D), Short-Form-36 and -8 health surveys (SF-36, SF-8), Sickness Impact Profile (SIP), and Quality of Well-being (QWB). Notably, in a systematic review of patients following ACL reconstruction, poorer health-related qualify of life measures were reported using the KOOS Quality of Life subscale than those assessed using a generic health-related qualify of life measure such as SF-36. The authors added the caveat that only a limited number of studies investigated these factors and would be a valuable direction for future research. Although there are PROs like the KOOS that broadly cover multiple domains, this comprehensive coverage comes with the risk of survey fatigue for patients. A concise and targeted PRO that covers all domains could be validated for patients with ACL and ligamentous injuries to the knee, but that would need to be further studied. It is our recommendation that IKDC and Marx, with the addition of SF-12 if a quality of life measure is desired, be used for the most comprehensive and efficient combination.

Limitations

There are several limitations to this study. First, only the seven most cited knee-specific PROs for ACL injury were selected for analysis, possibly excluding others that may provide valuable insight. For example, general health measures such as SF-36 and EQ-5D were not included but could provide supplementary information in evaluation of these patients. Second, the Marx and Tegner activity scores were not intended to be used in isolation. It may not be appropriate to compare the focused nature of these tools to the broader assessments sought by other PROs. Third, the clinician-reported portions of IKDC and CKRS were not included in the present study but may further distinguish these PROs from others. Fourth, the classification of questions as “identical,” “similar,” or “unique” is not a validated instrument. The classification for each question was agreed upon by all authors without an intra- or inter-rater reliability analysis performed. Finally, only the questions themselves were analyzed. The question format, answer choices, and scoring systems were not included in this analysis but could certainly impact patient response and score interpretation.

Conclusion

Nearly two-thirds of questions overlap between the commonly used PROs for ACL injury. Although Sports/Recreation is assessed by all PROs, each has its own pattern of coverage across this and other domains.

Appendix VI

Similar Questions

Domain	Question Stem	Question	IKDC	KOOS	Lysholm	Tegner	Marx	KOS	Cincinnati
Pain	Pain frequency	During the past 4 weeks, or since your injury, how often have you had pain?	+
		How often do you experience knee pain?		+
	Pain severity	If you have pain, how severe is it?	+
		Pain			+			+	+
Symptom	Stiffness/Swelling	During the past 4 weeks, or since your injury, how stiff or swollen was your knee?	+
		How severe is your knee joint stiffness after first wakening in the morning?		+
		How severe is your knee stiffness after sitting, lying or resting later in the day?		+
		Swelling (in your knee)?		+	+			+	+
		Stiffness						+
	Lock/Catch	During the past 4 weeks, or since your injury, did your knee lock or catch?	+
		Does your knee catch or hang up when moving?		+
		Locking			+
	Giving way	What is the highest level of activity you can perform without significant giving way in your knee?	+
		Instability ("Giving way sensation from the knee")			+
		Giving way, buckling, or shifting of the knee						+
		(Slipping or) Partial giving way						+	+
		(Buckling or) Full giving way						+	+
	Knee sensations (e.g., grinding)	Do you feel grinding or hear clicking or any other type of noise when your knee moves?		+
		Grinding or grating						+
Functional Activities	Stairs	Go upstairs (ascending)	+	+				+
		Go down stairs (descending)	+	+				+
		Stairs			+				+
	Kneeling	Kneel on the front of your knee	+					+
		Squatting / kneeling							+
	Squatting	Squatting	+		+			+
		Squatting / kneeling							+
	Sitting	Sit with your knee bent	+					+
		Sitting		+
	Rising	Rise from a chair	+					+
		Rising from sitting		+
	Function/condition	Current function on your knee	+
		Rate the overall condition of your knee at the present time							+
	Walking	Walking on flat surface		+
		Walking on even ground				+
		Walking						+	+
	Heavy domestic duties	Heavy domestic duties (moving heavy boxes, scrubbing floors, etc.)		+
		Work (Moderately heavy labor [e.g., truck driving, heavy domestic work])				+
Sports/Recreation	Highest level of activity	What is the highest level of activity you can participate in on a regular basis?	+
		Sports Activity Scale							+
	Walking uneven surface	Walking on uneven ground possible but impossible to walk in forest				+
		Walking on uneven ground							+
	Running	Run straight ahead / Straight running	+					+	+
		Running		+
		Running: running while playing a sport or jogging					+
	Jumping	Jump and land on your involved/affected leg	+					+	+
		Jumping		+
		Bandy; Squash or badminton; Athletics (jumping, etc.); Downhill skiing				+
		Competitive sports (tennis; athletics [running]; motocross, speedway; handball; basketball) or recreational sports (soccer, bandy, and ice hockey; squash, athletics [jumping], cross-country track, findings both recreational and competitive)				+
	Stopping/Starting	Stop and start quickly	+					+
		Deceleration: coming to a quick stop while running					+
	Pivoting	Twisting/pivoting on your injured knee		+
		Pivoting: turning your body with your foot planted while playing sport, e.g., skiing, skating, kicking, throwing, hitting a ball (golf, tennis, squash).					+
		Cut and pivot on your involved leg						+
		Hard twists / cuts / pivots							+
	Cutting	Cutting: changing directions while running					+
		Cut and pivot on your involved leg						+
		Hard twists / cuts / pivots							+

Note that questions listed may also appear in Table 2 (Identical Questions) because two questions are identical, but a question from another survey is similar to the two identical questions. As a result, two of the questions would be identical and the third would be similar.