From Control to Chaos: Visual-Cognitive Progression During Recovery from ACL Reconstruction.

BACKGROUND: Anterior cruciate ligament tear is a serious knee injury with implications for central nervous system (CNS) plasticity. To perform simple knee movements, people with a history of ACL reconstruction (ACL-R) engage cross-modal brain regions and when challenged with cognitive-motor dual-tasks, physical performance deteriorates. Therefore, people with ACL-R may increase visual-cognitive neural processes for motor control. CLINICAL QUESTION: What components of CNS plasticity should the rehabilitation practitioner target with interventions, and how can practitioners augment rehabilitation exercises to target injury associated plasticity? KEY RESULTS: This clinical commentary (1) describes the neurophysiological foundation for visual-cognitive compensation after ACL-R, (2) provides a theoretical rationale for implementing visual-cognitive challenges throughout the return to sport (RTS) continuum, and (3) presents a framework for implementing visual-cognitive challenges from the acute phases of rehabilitation. The 'Visual-Cognitive Control Chaos Continuum (VC-CCC) framework consists of five training difficulties that progress visual-cognitive challenges from high control to high chaos, to better represent the demands of sport. CLINICAL APPLICATION: The VC-CCC framework augments traditional rehabilitation so that each exercise can progress to increase difficulty and promote sensorimotor and visual-cognitive adaptation after ACL-R.

Progressing On-Court Rehabilitation After Injury: The Control-Chaos Continuum Adapted to Basketball.

BACKGROUND: Sport-specific training is an integral component of returning to sport following injury. Frameworks designed to guide sport-specific rehabilitation need to integrate and adapt to the specific context of elite sport. The control-chaos continuum (CCC) is a flexible framework originally designed for on-pitch rehabilitation in elite football (soccer). The concepts underpinning the CCC transfer to other elite sport rehabilitation environments. CLINICAL QUESTION: How can practitioners and clinicians transfer the CCC to elite basketball, to support planning and return to sport? On-court rehabilitation is a critical sport-specific rehabilitation component of return to sport, yet there are no frameworks to guide practitioners when planning and delivering on-court rehabilitation. KEY RESULTS: Based on our experience working in the National Basketball Association, we report how the CCC framework can apply to elite basketball. We focus on the design and delivery of progressive training in the presence of injury in this basketball-specific edition of the CCC. Given the challenges when quantifying "load" in basketball, we encourage practitioners and clinicians to consider the qualitative aspects of performance such as skill, sport-specific movement, contact, and decision making. CLINICAL APPLICATION: The 5-phase framework describes training progression from high control, a return to on-court running, to high chaos, a return to "live" unrestricted basketball. The model can be adapted to both short- and long-term injuries based on injury and progression criteria. Strength and power "diagnostics" can be strategically implemented to enhance decision making throughout the return to sport continuum. J Orthop Sports Phys Ther 2023;53(9):1-12. Epub: 9 August 2023. doi:10.2519/jospt.2023.11981.

Interchangeability of optical tracking technologies: potential overestimation of the sprint running load demands in the English Premier League.

PURPOSE: The purpose of this study was to assess the agreement between match-derived running load outputs; total distance (TD), high-speed running (HSR) and sprint distance (SPR) obtained by two optical tracking systems. METHODS: Data were collected from 31 elite footballers from the first team and under-21 squads of an English Premier League (EPL) football club across three competitive matches. One EPL game (game 2) and one under-21 Premier League game (game 3) were played at the team's home stadium and one EPL game (game 1) at an away venue. All matches were tracked concomitantly using eight colour cameras sampling at 10 Hz (PROZONE®) and six high-definition motion cameras sampling at 25 Hz (TRACAB®). RESULTS: TD displayed a perfect (r = 0.99) correlation while HSR and SPR displayed very large (r = 0.81 and r = 0.73) correlations between TRACAB® and PROZONE®. Mean biases were 5% for TD, -3% for HSR and 61% for SPR. Between games, mean biases for TD were 6% for game 1, and 5% for game 2 and game 3. For HSR, 9% for game 1, -5% for game 2 and 6% for game 3 and for SPR, 31% for game 1, 71% for game 2 and 84% for game 3. CONCLUSION: TD and HSR can be interchanged between PROZONE® and TRACAB®, to allow accurate interpretation between the two optical systems. PROZONE® overestimated SPR compared to the TRACAB®, with the magnitude of difference considered meaningful, altering interpretation of historical match outputs, sprint volume trends in the EPL and forecasts of the modern game.

Detraining of specific neuromuscular qualities in elite footballers during COVID-19 quarantine.

The COVID-19 pandemic forced elite football leagues into extended breaks followed by prompt resumption of competition. Inadequate periods of on-pitch football-specific training may underlie the increased injury incidence reported following restart in a non-peer reviewed report. Detraining effects from isolated training are expected, but existing models do not completely describe the unprecedented conditions imposed by COVID-19.Providing insight into specific neuromuscular qualities affected by extended absence of football-specific training, we share countermovement jump performance and kinetic data from an elite team's assessments pre and post 15 weeks of isolated training, and to contextualise these trends, off-season changes with no training.The isolated circuit resistance and aerobic interval training maintained jump height and Reactive Strength Indexmodified, but there were moderate magnitude (p = 0.01-0.04) changes in eccentric 'yielding' and landing 'loading' phase variables. These changes suggest a compromised initiation of countermovement deceleration, impact attenuation and altered coordination/motor control strategies or muscle-tendon properties. This analysis may have revealed kinetic markers specifically stimulated by football-specific training/competition, relevant to post-quarantine monitoring. Lower landing forces may reduce overuse injury risk, while yielding phase alterations suggest a negative effect on reactive performance, therefore the overall effect on vulnerability to injury is unclear.

Managing the return to sport of the elite footballer following semimembranosus reconstruction.

Hamstring strains are the most common injury in elite football and typically occur during high-speed running. Despite its important contribution to power production in the late swing phase, injury to the semimembranosus (SM) is less common than to the biceps femoris, but may involve the free tendon and depending on the degree of retraction, warrant surgical repair. Few case reports detail clinical reasoning, supported by objective data during rehabilitation in elite footballers, and none have described the return to sport (RTS) process following this type of hamstring injury. In this article, we outline the management and RTS of an English Premier League (EPL) footballer who suffered a high-grade SM proximal tendon tear during training. Due to the degree of retraction of the free tendon, the player underwent surgical reconstruction at the recommendation of an orthopaedic surgeon. Early physiotherapy care, nutritional support, on- and off-pitch injury-specific reconditioning and global athletic development are outlined, alongside strength and power diagnostic and global positioning systems data, assessment of pain, player feedback and MRI informed clinical reasoning and shared decision-making during the RTS process. 18 weeks post-surgery the player returned to team training, transferring to a new club 3 weeks later. 2.5 years post RTS, the player remains free of re-injury playing regularly in the EPL.

Physical preparation and return to performance of an elite female football player following ACL reconstruction: a journey to the FIFA Women's World Cup.

ACL injuries are among the most severe knee injuries in elite sport, with a high injury burden and re-injury risk. Despite extensive literature on the injury and the higher incidence of injury and re-injury in female athletes, there is limited evidence on the return to sport (RTS) of elite female football players following ACL reconstruction (ACLR). RTS is best viewed on a continuum aligning the recovery and rehabilitation process with the ultimate aim - a return to performance (RTPerf). We outline the RTS and RTPerf of an elite female football player following ACLR and her journey to the FIFA Women's World Cup, including the gym-based physical preparation and the on-pitch/sports-specific reconditioning. We used the 'control-chaos continuum' as a framework for RTS, guiding a return above pre-injury training load demands while considering the qualitative nature of movement in competition. We then implemented the 'RTPerf pathway' to facilitate a return to team training, competitive match play and a RTPerf. Objective information, clinical reasoning and shared decision-making contributed to this process and helped the player to reach her goal of representing her country at the FIFA Women's World Cup.

Physical preparation and return to sport of the football player with a tibia-fibula fracture: applying the 'control-chaos continuum'.

Contact in elite football can result in severe injury such as traumatic fracture. Limited information exists regarding the rehabilitation and return to sport (RTS) of these injuries especially in elite football. We outline the RTS of an elite English Premier League footballer following a tibia-fibula fracture including gym-based physical preparation and the use of 'control-chaos continuum' as a framework for on-pitch sport-specific conditioning, development of technical skills while returning the player to pre-injury chronic running loads considering the qualitative nature of movement in competition. Strength and power diagnostics were used to back up clinical reasoning and decision-making throughout rehabilitation and the RTS process. The player returned to full team training after 7.5 months, completed 90 min match-play after 9 months and remains injury-free 11 months post-RTS.

Isometric Posterior Chain Peak Force Recovery Response Following Match-Play in Elite Youth Soccer Players: Associations with Relative Posterior Chain Strength.

: The purpose of this study was to determine changes in two tests of lower limb isometric posterior chain force (IPC-F) following 90 min of match-play in elite youth soccer players and the interaction between relative strength and recovery profile. 14 players (age: 16 ± 2 years) performed 3 × 3 second IPC-F tests unilaterally at 30° and 90° of knee and hip flexion pre- and post-match, +24 h, +48 h, and +72 h post-match. Peak force was recorded for both limbs, combined and expressed relative to bodyweight (N/kg). A two-way repeated measures analysis of variance was performed to determine differences in force output between joint angles, time intervals and subjects. As there was no interaction between angle and time (p = 0.260), we report the change between timepoints as mean Δ in 90° + 30° IPC-F. Relative to pre-match IPC-F, there were significant decreases post (Δ = -18%; p > 0.001) and at +24 h (Δ = -8%; p = 0.040), no significant difference at +48 h (Δ = 0%; p = 0.992) and a significant increase at +72 h (Δ = +12%; p = 0.005). There was a large inter-individual variability in recovery profile at both angles and substantial differences between post-match deficits at 90° (-10.8%) compared to 30° (-20.7%). Higher pre-match IPC-F was correlated with the magnitude of IPC-F deficits at both angles and all time points (r = 0.56 to 0.70, p = < 0.01) except for post-match 90°. Regular IPC-F monitoring to determine the magnitude of match-induced fatigue and track recovery may help inform decision-making regarding modifications to individual players training load, particularly as there is a large inter-individual variability in response to competition. Further research is warranted to better understand and address the finding that stronger players showed larger force deficits and slower recovery following match-play.