*Article* **Composite Score of Readiness (CSR) as Holistic Profiling of Functional Deficits in Footballers Following ACL Reconstruction**

**Łukasz Oleksy 1,2,3,\*, Anna Mika 4, Aleksandra Królikowska 5, Maciej Kuchciak 6, Magda Stolarczyk 7, Renata Kielnar 8, Henryk Racheniuk 9, Jan Szczegielniak 9, Edyta Łuszczki <sup>8</sup> and Artur Stolarczyk <sup>1</sup>**


**Abstract:** Background: The decision to return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction is difficult; thus, coaching staff require a readable, easy-to-use, and holistic indication of an athlete's readiness to play. Purpose: To present the Composite Score of Readiness (CSR) as a method providing a single score for RTS tests after ACL reconstruction. Methods: The study comprised 65 male football players (age 18–25 years), divided into three groups: ACL group subjects after ACL rupture and reconstruction, Mild Injury (MI) group—subjects after mild lower limb injuries, and Control (C) group—subjects without injuries. The CSR was calculated based on three performed tests (Y-balance test, Functional Movement Screen, and Tuck Jump Assessment) and expressed as the sum of z-scores. The CSR index allows highlighting an athlete's functional deficits across tests relative to the evaluated group. Results: The CSR indicated that relative to the group of athletes under the study, similar functional deficits were present. Comparing athletes following ACL reconstruction to both the MI and C groups, in the majority of subjects, the CSR index was below zero. The correlation between CSR and raw tests results indicated that the CSR is most strongly determined by YBT. Conclusion: The CSR is a simple way to differentiate people after serious injuries (with large functional deficits) from people without injuries or with only small deficits. Because the CSR is a single number, it allows us to more easily interpret the value of functional deficits in athletes, compared to rating those deficits based on raw tests results.

**Keywords:** anterior cruciate ligament (ACL); composite score of readiness (CSR); injury prevention; rehabilitation; football; soccer

### **1. Introduction**

Anterior cruciate ligament (ACL) injuries are very common in sports [1]. The most important goal for athletes after ACL reconstruction is a successful return to play [1,2]. It has been reported that from 78% to 98% of professional athletes, and 65% of amateurs, return to pre-injury level [3]. However, 74% of ACL re-injuries occur within the first

**Citation:** Oleksy, Ł.; Mika, A.; Królikowska, A.; Kuchciak, M.; Stolarczyk, M.; Kielnar, R.; Racheniuk, H.; Szczegielniak, J.; Łuszczki, E.; Stolarczyk, A. Composite Score of Readiness (CSR) as Holistic Profiling of Functional Deficits in Footballers Following ACL Reconstruction. *J. Clin. Med.* **2021**, *10*, 3570. https:// doi.org/10.3390/jcm10163570

Academic Editors: David Rodríguez-Sanz and Christian Carulli

Received: 19 July 2021 Accepted: 12 August 2021 Published: 13 August 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

2 years [3]. After ACL reconstruction, the deficits were observed in postural stability as well as in alterations in knee and hip function. It was suggested that they might be associated with pathological movement patterns leading to further tissue overloads, and often, to ACL re-injury [4–6]. It has been suggested that return-to-sport (RTS) testing after ACL reconstruction should include several tests, such as isokinetic strength, hop test, and a jump landing task assessed with the Landing Error Scoring System or Tuck Jump Assessment (TJA) [6–9]. Additionally, movement patterns, mobility, and stability evaluation with the Functional Movement Screen (FMS) and dynamic balance via the Y-balance test (YBT) or the star excursion balance test were also recommended [9].

The decision to RTS after ACL reconstruction is difficult for clinicians to make. Moreover, the coaching staff require a readable, easy-to-use, and holistic indication of an athlete's readiness to play [10]. This has raised a need to provide a single score to assess athletes' RTS, rather than separately discussing each individual test result [10,11]. As we know, the athletes are regularly put through many tests whose individual results collected together produce an overwhelming amount of data [10–12]. Some authors propose identifying fewer but more predictive tests [8,13]. Others provide us with strategies that aim to reduce the data without decreasing the number of performed tests, such as Total Score of Athleticism (TSA), a single score of an athlete's holistic athleticism introduced by Turner [10]. This way of assessment, by creating a single index, is already known in the literature. Such indices were used in gait evaluation [14–17]. The Gait Deviation Index (GDI), Gillette Gait Index (GGI), or Normalcy Index (NI) were derived to calculate the amount by which a subject's gait deviates from an average normal profile and to represent this deviation as a single number [14–17]. The other index, called "Total Score of Athleticism (TSA)", was described by Thurner et al. [10,11], and allowed coaches to examine the athleticism level of individual athletes relative to their teammates. This approach provided coaches with quick and easy-to-read data indicating how well each athlete performed in the tests relative to their teammates, and which areas are strengths, and which are weaknesses [10,11].

It is known that for coaches, most important is that the evaluation and interpretation of test results for a given athlete are clear and easy to interpret and that they are read in the same way by others. Direct reference to the baseline value (indicating a correct result) may allow for a precise assessment of the size of an athlete's deficits. Following the TSA model, we would like to propose the injury risk index called "Composite Score of Readiness (CSR)". This study is the first in which a single score index for RTS evaluation is described, which may differentiate athletes following a serious injury such as ACL reconstruction from athletes after mild musculoskeletal injuries and healthy controls. This index may allow assessing the level of functional deficits in these athletes. Therefore, the purpose of this study was to present the Composite Score of Readiness (CSR) as a method providing a single score for RTS tests after ACL reconstruction.

#### **2. Methods**

#### *2.1. Participants*

The studied participants involved 65 male football players belonging to regional teams participated in this study. Basing on a medical interview and gathered medical documentation, the players were divided into three groups, named consecutively "Group 1 (ACL)", "Group 2 (MI)", and "Group 3 (C)". The three groups were similar in age, body weight, and body height, as presented in Table 1. Based on medical interviews and gathered medical documentation, they were free of the following diagnosed medical problems: currently experiencing pain and movement restriction, respiratory and circulatory system diseases, bilateral injuries in the lower limbs in the history, injuries of the trunk in the past, injuries of upper limbs in the past, and they gave consent to participate in research. The inclusion criteria in Group I were: clearance to play by an orthopedic specialist after primary unilateral ACL rupture and following arthroscopic reconstruction underwent during the 3 years before the research; bone–patellar, tendon–bone, or hamstring tendon autographs used during ACL reconstruction; no abnormalities and no history of injury

in the contralateral knee; no to all of the following procedures: medial and/or lateral meniscectomy, medial and/or lateral meniscal transplant, posterior cruciate ligament repair, and medial or/and lateral collateral ligament repair/reconstruction osteoarthritis surgery in the ACL-reconstructed knee other than shaving; the lack of any upper limbs and trunk injuries in the past. The inclusion criteria in Group 2: clearance to play by an orthopedic specialist after grade I or "mild" lower limb muscle injury according to Grassi et al. [18] and following conservative treatment undergone during the 3 years before the research; no history of any other injuries in lower limbs, the lack of any upper limbs and trunk injuries in the past. The inclusion criteria in Group 3, a control group, was the lack of any lower and upper limbs and trunk injuries in the past.



No significant difference was found for any variable.

Group 1 (ACL) (*n* = 24)—subjects after ACL rupture and reconstruction in previous 2–3 years who passed RTS including orthopedic and manual tests performed by a physiotherapist, muscle strength evaluation and hop tests, and were cleared to play (involved leg—after ACL reconstruction, uninvolved leg—contralateral limb without ACL injury);

Group 2 (MI) (*n* = 21)—subjects after mild lower limb injury in previous 2–3 years (involved leg—after mild injury, uninvolved leg—contralateral limb without injury);

Group 3 (C) (*n* = 20)—control group without injuries (the left limb was the equivalent of the involved limb and the right limb was the equivalent of the uninvolved limb).

The study participants were informed in detail about the research protocol and gave their written informed consent to participate in the study. Informed consent was acquired from the parent for participants under the age of 18. Approval of the Ethical Committee of Regional Medical Chamber in Kraków was obtained for this study (16/KBL/OIL/2016). All procedures were performed in accordance with the 1964 Declaration of Helsinki and its later amendments.
