At this time of the year, as a physical therapist who specializes with skiers, it’s normal to rarely treat skiing-related injuries, except for an end-of-the-season ACL surgical reconstruction. What’s not normal for this time of the year is to have training severely restricted and in some states nonexistent. What was supposed to be used as invaluable time to physically prepare for the next ski season has been significantly reduced to home or outside workouts with limited equipment leading to atrophy and deconditioning. This can have damaging implications for skiers. The training calendar is a highly coordinated system. It’s designed to lower injury risk and improve performance through repeated exposure to loads during snow and dryland training. Skiers require diligent loading during the offseason to safely tolerate the high energy demands of skiing. But the novel coronavirus does not allow for traditional training to achieve those goals. In my estimation, the novel coronavirus will pose the largest injury threat to skiers ever witnessed, with return to snow producing injuries at an unforeseen clip unless we can find ways to mitigate the damage.
A combination of risk factors including high skiing speed, athlete strength, equipment, snow conditions, course/terrain changes, and the risk-consuming attitudes of a skier makes skiing one of the most dangerous sports. In comparison to other “activities” skiing has the highest incidence of ACL tears1. In fact, ACL injuries are the most common diagnosis of skiing injuries, occurring 13.6% of the time, with the knee being the most frequently injured body part 35.6% of the time.2 ACL surgery and the rehab can require the athlete to miss up to 2 years of skiing, with up to only 55% of athletes being able to return to pre-injury competitive levels.3 If you are lucky to return back to a high level of competition, 19% of all skiers will tear the same ACL, 30% of skiers will injure the opposite ACL, and 28% of skiers will require at least one revision surgery about 3.5 years following the primary injury.4,5 Even a minor knee sprain forces an athlete to miss on average 28 days of skiing.6 However, it’s not just traumatic injuries skiers have to worry about. The second most common diagnosis is chronic low back pain, 11.5% of all injuries, due to the repetitive absorption of high centripetal and gravitational forces acting on the spine at a dangerous resonant frequency.2 Diagnostic imaging studies examining the thoracolumbar spine of young alpine competitive ski racers show early onset degenerative changes that are not seen in their age related peers who don’t ski.7 And to make you feel even less optimistic about the injury risk you face skiing, it’s going to get even worse in a COVID world. For the following three reasons expect to see a commensurate increase in the incidence of skiing related injuries due to a higher annualized loss of training time.
First, the varying levels of restrictions imposed on gyms at a state level has undoubtedly led to increased athlete muscular atrophy. One of the five strongest predictors of primary and secondary ACL injuries are strength of the quadriceps and hamstring muscles.8 To be more specific: the absolute strength of each muscle, the ratio of strength between the two muscles, the index of strength between both legs, the reactive strength during unexpected perturbations, and power strength can be used to screen for athletes at high risk for the knee being in a position where ACL tears commonly occur. Strengths of these muscles are vital to carrying out the high-velocity, slow eccentric contraction that occurs during the turning phase of skiing and to prevent the quadriceps from asymmetrically pulling on the ACL. The two most important exercises to mitigate atrophy of these muscle groups can be elevated loaded split squats and eccentric single leg Glute-Ham Developer (GHD) curls.
Second, I forecast skiers mismanaging their return to training workload by quickly ramping up to recover lost time. This will lead to an unsafe increase in repetitive overuse soft tissue injuries that might limit the athletes from even getting onto the snow. The most common injuries from mis-conditioning are iliotibial band syndrome (ITBS), plantar fasciosis, and achilles tendinosis. These injuries can sideline skiers on average 82 days from training with a significant risk of re-injury when trying to return back to sport less than 10 days after the initial injury.9,10 To prevent unsafe ramping up for conditioning I would abide by the conservative rule of thumb-even though it lacks strong evidence-of increasing your mileage or duration by 10% every 1-2 weeks. In addition, quickly progressing the weight when strengthening can lead to repetitive overuse soft tissue injuries of the hip flexor and hamstring muscle groups which can take on average 6-8 weeks to recover. To prevent these strengthening injuries I would make sure to always include 2-4 ramp up sets before working sets, and to spend 2-4 weeks in each strengthening phase before progressing to the next.
Third, there is an inequitable amount of attention given to the psychosocial status of the skier in determining their readiness to ski at their highest level. Healthcare professionals build injury and re-injury risk profiles based on the aggregation of physical values including strength during single leg hopping tasks11 But new information reveals there is no difference in re-injury for skiers who pass these strength tests and return to sport either early (<6 months), on average (9-12 months), or late (12-24 months).11,12 Therefore, the risk profile needs to be amended to represent the whole skier and not just their strength characteristics. The missing link is sought to be psychosocial. All skiers should be given a baseline assessment of their psychosocial state. For the non-injured athlete they can take the Tampa Scale of Kinesiophobia-11 and for injured athletes the Anterior Cruciate Ligament Return To Sport after Injury (ACL-RSI) can be used to gauge psychosocial attitudes with abnormal responses being further investigated to determine the readiness of the athlete to return back to sport.
Don’t become another injury statistic in the era of Covid skiing. Make these safe changes to your training program during these challenging times to reduce the risk of injury and improve your skiing performance.
- Montalvo AM, Schneider DK, Webster KE, Yut L, Galloway MT, Heidt RS et al. Anterior cruciate ligament injury risk in sport: A systematic review and meta-analysis of injury incidence by sex and sport classification. J Athl Train. 2019;54(5):472-482. Doi: 10.4085/1062-6050-407-16.
- Sporri J, Kroll J, Gilgien M, Muller E. How to prevent injuries in alpine skiing: What do we know and where do we go from here? Sports Med. 2017; 47:599-614. Doi: 10.1007/s40279-016-0601-2.
- Ardern CL, Taylor NF, Feller JA, Webster KE. Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. Br J Sports Med. 2014;48:1543-1552.
- Jordan MJ, Aagaard P, Herzog W. Anterior cruciate ligament injury/reinjury in alpine ski racing: a narrative review. Open Access J Sports Med. 2017; 8:71-83. https://dx/doi.org/10.2147/OAJSM.S106699.
- Jordan MJ, Doyle-Baker P, Heard M, Aagaard P, Herzog W. A retrospective analysis of concurrent pathology in ACL-reconstructed knees of elite alpine ski racers. Orthop J Sports Med. 2017;5(7):1-7.
- Florence TW, Bere T Nordsletten L, Heir S, Bahn R. Injuries among male and female World Cup Alpine skiers. Br J Sports Med. 2009;43(13):973-978.
- Rachbauer F, Sterzinger W, Eibl G. Radiographic abnormalities in the thoracolumbar spine of young elite skiers. Am J Sports Med. 2001;29(4):446-449.
- Hewett TE, Webster KE, Hurd WJ. Systematic selection of key logistic regression variables for risk prediction analyses: A five factor maximum model. Clin J Sport Med. 2019;29(1):78-85.
- Gajhede-Knudsen M, Ekstrand J, Magnusson H, Maffulli N. Recurrence of achilles tendon injuries in elite male football players is more common after early return to play: an 11-year follow-up of the UEFA Champions League injury study. BR J Sports Med. 2013;47:763-768.
- Nielsen RO, Ronnow L, Rasmussen S, Lind M. A prospective study on time to recovery in 254 injured novice runners. PLoS One. 2014;9.
- Webster KE, Hewett TE. What is the evidence for and validity of return -to-sport testing after anterior cruciate ligament reconstruction surgery? A systematic review and meta-analysis. Sports Med. 2019;49(6):917-929.
- Zwolski CM, Schmitt LC, Thomas S, Paterno MV. The incidence of second anterior cruciate ligament injury in young athletes is not influenced by time to return to sport. Orthopedic Journal of Sports Medicine. 2020;8(4): (suppl 3). https://doi.org/10.1177/2325967120S00188