CSP2023: 441 A series of single-case experiments exploring cryotherapy interventions in semi-professional football players with medial collateral ligament injuries

Abstract

Purpose: Knee injuries continue to be a common site of injury in sport, affecting people of all ages. Medial Collateral Ligament (MCL) injuries are one of the most prevalent knee injuries in football. Cryotherapy and compression are advised in clinical guidelines for knee injury management. However, optimal compressive-cryotherapy protocols have not yet been defined. This highlights the need for exploration into the effectiveness of different cryotherapy interventions on a range of injuries. This series of single-case experiments aimed to explore the effects of two cryotherapy interventions on pain, swelling and stability in football players with an MCL injury, in order to inform the development of evidence-based interventions for knee injury management.

Methods: Five semi-professional football players with an MCL injury (age: 24.8 ± 3.8 yrs.; n=1 females, n=4 males; injury severity: n=4 grade 1, n=1 grade 3) were recruited. An alternating-treatment design was adopted, over a series of five single-case experiments, exploring two 20-minute interventions (A) wetted ice (400g ice, 400ml water) and (B) ProMOTION EV1 compressive-cryotherapy device (10°C with 50mmHg compression). The order of intervention was randomised (ABABAB or BABABA). Each intervention was applied once a day for three consecutive days, with a minimum of two hours in between. Three outcome measures were recorded pre- and post-intervention: i) Swelling using a standard tape measure, ii) Pain using the 11-point numeric pain rating scale, iii) Stability on an 11-point scale (very unstable – very stable). The data was analysed using visual analysis of graphical data individually and collectively. All outcome measures were assessed for the clinical relevance using minimal clinically important changes.

Results: Eighty percent of players reported a reduction in pain on days 1, 2 and 3 for both interventions; 75% of which reported clinically important reductions in pain (≥1 point). Both interventions achieved the same number of clinically important pain reductions in total (8 out of 15 sessions). Both interventions illustrated small effect sizes for pain reduction each day (ice: d=0.2-0.4, EV1: d=0.2-0.3). Clinically important swelling reductions were recorded in all 5 players following compressive-cryotherapy using ProMOTION EV1, and in 20% of players using ice. Interestingly, both interventions recorded the largest effect on swelling on day 1 (ice: d=0.2, EV1: d=0.4). However, both interventions had limited effect on patient-perceived stability, only 6% of compressive-cryotherapy interventions and 0% of ice interventions observed clinically important increases. Individual analysis of the total number of clinically important changes showed that compressive-cryotherapy was the most effective intervention for all 5 semi-professional football players.

Conclusion(s): There is a significant lack of evidence-based cryotherapy interventions for knee injury management. Using compression and cryotherapy simultaneously, using ProMOTION EV1, reduced swelling more effectively than the current standard clinical treatment, in semi-professional football players with an MCL injury. The findings show that combining compression and cryotherapy could offer a greater therapeutic effect than cryotherapy alone. Further research is recommended to continue to develop evidence-based cryotherapy interventions for injury management.

Impact: Establishing evidence-based interventions to alleviate knee injury symptoms could help clinicians to advise individual compressive-cryotherapy interventions and optimise individuals’ ability to self-manage symptoms.