February 2013

Over the Edge: Lower extremity injuries in figure skaters

cover_mainCompetitive figure skating today is much less about artistry and much more about athleticism than in years past. Training is longer and harder than ever, while the classic unforgiving skate boot design has remained essentially unchanged. And lower extremity injuries in skaters are on the rise.

By Nathan W. Saunders, MA, and Steven T. Devor, PhD, FACSM

The sport of ice figure skating in the US has experienced a tremendous increase in participation in the last two decades. United States Figure Skating Association (USFSA) membership has grown from 100,000 members in 1992 to more than 173,000 members in 2012; 73% of current members are women or girls and 64% of all members are younger than 18 years.1

Membership growth has coincided with two major structural changes in the USFSA and International Skating Union rules that skaters must adhere to when competing in officially sanctioned events. The new rules have dramatically increased the physical demands placed on the athletes and, we believe, have resulted in a greatly increased number of skating-related injuries.

First, in 1990, was the elimination of “school figures,” which were characterized by circular patterns drawn on the ice that athletes were required to trace as they skated to demonstrate skill in placing precise turns evenly on round circles.2 The elimination of school figures has permitted skaters to spend considerably more time practicing free skating elements (e.g., jumps, spins, footwork, and lifts).3

Second, in 2004, in an attempt to make judging less subjective, governing bodies reevaluated and ultimately replaced the six-point scoring system with the International Judging System (IJS).4 Compared with the traditional scoring system, the IJS: awards points for each specific element in a routine rather than recording a single mark to represent the entire routine; removes some of the subjectivity previously associated with figure skating judging, as now the judges do a much better job of rewarding overall skating quality; and, not only encourages skaters to maximize the difficulty of each element within the overall routine, but also rewards skaters with bonus points for putting the most physically challenging elements of the performance in the second half of the routine.

To achieve success at the elite level in the early 2000s, figure skaters practiced up to six hours per day, six days per week, for 11 months a year.3 The majority of the training focused on jumps, spins, footwork, and lifts. While there are no updated statistics, it is reasonable to assume these challenging skills are presently emphasized even more. Not surprisingly, injuries are not uncommon.

While pairs skaters and ice dancers typically report a predominance of acute overuse injuries to all body regions, singles skaters incur injuries primarily to the lower extremities.3,5 Fortin and Roberts5 reported that approximately 66% of all self-reported injuries in nationally competitive figure skaters were in the lower extremities, with ankle injuries representing the greatest percentage (27.7% of all self-reported injuries). A significant portion of overuse injuries in figure skating6 and all athletic pursuits are preventable through appropriate training and rest cycles. Therefore, we aim to highlight the most common overuse injuries in figure skating and discuss etiologies, as well as possible treatment and prevention strategies. We will also address some general safety concerns and equipment considerations that warrant significant attention.

Chronic lower extremity injuries

The proposed etiologies of most preventable figure skating chronic injuries to the lower extremity tend to fall into one or more of the following categories: boot structure and design, training volume, jump mechanics, and muscle inflexibility (Table 1).

Injuries related to boot structure and design. One of the more curious things about the sport of figure skating is the development of the skate boot: it was designed to be aesthetically pleasing as opposed to enhancing performance of figure skating skill elements. Even with major advancements in our understanding of skating biomechanics, as well as the availability of less expensive and more durable synthetic materials, the skate boot has remained largely unchanged for more than 100 years.6-8 Figure 1A illustrates a skate likely to be worn as early as the 1920s, while Figure 1B is an example of a currently manufactured custom boot.

Skate boots are composed primarily of multiple layers of leather that are hard and rigid when first purchased and then begin to “break in” with wear and subsequently “break down” with further use. In addition to the continual structural degradation that occurs throughout the life of the boot, its structural integrity changes within a single training session as it absorbs sweat and heat from the skater. Often, there is insufficient time between training sessions for the boots to dry fully, and this leads to a more rapid breakdown of the leather.

Figure 1. Evolution of skate structure and design from 1920 (A) to present (B). Both skates are similar in overall design, but currently manufactured boots are significantly thicker and provide better ankle support.

Figure 1. Evolution of skate structure and design from 1920 (A) to present (B). Both skates are similar in overall design, but currently manufactured boots are significantly thicker and provide better ankle support.

A large proportion of skaters’ training is spent breaking in boots or skating in broken-down boots, with little time spent training in optimal equipment. Pelham et al9 found that boots may wear out in as little as three weeks, yet skaters typically wear the same boots for six months to a year. The resulting inconsistent level of boot ankle support not only contributes to performance inconsistency, and we suggest it may also increase the risk of ankle sprains, especially if the rate of change in boot ankle support exceeds the rate that skaters’ musculoskeletal systems are able to compensate. Our recommendation to boot manufacturers is to replace leather with synthetic materials that dry quickly and are more resistant to acute and long-term changes in structural support. Until such products are readily available, skaters who train daily should have a minimum of two pairs of skates to rotate on alternate days.

Bone spurs, hammertoes, calluses, and bursae. Though the overall boot design has changed little, skaters and their coaches have progressively requested thicker boots to provide added ankle support for more difficult jumps; these jumps involve a greater number of rotations, which are associated with greater forces at both takeoffs and landings).6,8 The thick and rigid boots in many cases apply substantial and uneven pressure to many bones and other tissues of the foot and ankle. The resulting repeated microtrauma from skating in this sort of boot may lead to the formation of bone spurs,10,11 hammertoes and calluses,6,8,12 and adventitious bursae.10,12-14 The most common sites of insult are the lateral aspect of the fifth metatarsal, posterior-lateral calcaneus, and medial and lateral malleoli. Often there is little to no perceived pain at the time of injury, but if ignored, these injuries may influence performance negatively or prohibit skating completely.15

It is challenging to identify and correct areas of high-pressure during the initial boot fitting as the process relies heavily on the experience of both the skater and the boot salesperson.  Additionally, problem areas not observed during an off-ice fitting may arise during on-ice skating maneuvers.

At the first visible or perceived sign of trauma (e.g., skin irritation, swelling, lacerations, or bony protrusions), treatment should begin with boot modifications (decreasing boot thickness or “punching out” areas of high pressure) or the addition of doughnut-shaped pads to distribute the compressive forces to the surrounding area. A short break from skating may also be necessary. Only when conservative treatments have proven ineffective are more aggressive surgical techniques warranted. Many of these injuries may be prevented if areas of discomfort are identified early and addressed with appropriate boot modifications, strategically placed padding, and rest.

Tendinitis and tenosynovitis. The tibialis anterior, toe extensor, and Achilles tendons are especially susceptible to development of boot-induced tendinitis6,9,12 and tenosynovitis.10 Anteriorly, ankle dorsiflexion is limited by the rigid nature of the boot. During the takeoff and landing phases of jumps, the anterior tendons are compressed and also sustain shear forces. This may be exacerbated if the tongue of the boot deviates laterally, as is often the case, or is not padded sufficiently. Posteriorly, the unforgiving boot top applies compressive and shear forces to the Achilles tendon during extreme ankle plantar flexion, a movement required for jump takeoffs as well as for standard forward and backward skating.

Padding the boot top circumferentially is a convenient and effective place to begin treatment. It may also help modify the boot top design such that it slopes rather than abuts the ankle at a right angle. The addition of “heel huggers” can secure the heel better in the boot and reduce rubbing on the Achilles tendon. Finally, a well-padded tongue and sound lacing technique can distribute the compressive forces placed on the foot’s anterior compartment more evenly. All previously mentioned treatment options may also serve as prevention strategies. In addition, when skaters are breaking in new boots, it is especially important that they secure the tongue to prevent its lateral movement (procedures are described else­where).6

Stress fractures. As many as 20% of all figure skating injuries are stress fractures, with the majority occurring in skaters aged 16 to 20 years.10 Smith et al12 suggested the common occurrence of metatarsal stress fractures was likely related to a lack of shock absorption provided by the skate during landings.  The rigid boot limits ankle dorsiflexion and knee flexion, directing a significant amount of the impact forces to the metatarsals. Fortin et al16 found rigid boots reduced dorsiflexion by 10º and plantar flexion by 15º.

Bruening and Richards17 attempted to address the issue of limited ankle range of motion (ROM) by designing a boot with a hinged ankle. Compared with traditional boots, their articulated boot reduced impact forces in off-ice testing, though on-ice results demonstrated no such benefit. Importantly, while their articulated boot addressed the issue of restricted sagittal ROM at the ankle, it did not address the issue of a biomechanically unfavorable raised heel. As is the case with all conventional figure skates (Figure 1B), the articulated boot featured a raised heel, which puts the ankle in a “neutral” position of approximately 15º of plantar flexion.16 The raised heel reduces jump height,18 changes the lower limb joint coordination,18 and may increase impact forces by limiting ankle joint dorsiflexion.12

Interestingly, unpublished data from our lab suggest that female (and likely male) figure skaters tend to resist ankle dorsiflexion during landings, even when barefoot, which likely contributes to greater impact forces. In fact, the skaters in our study actually exhibited greater impact forces than untrained control participants when performing barefoot drop landings on a force plate. Bruening et al17 also observed that some skaters tend to resist dorsiflexion of the ankle, even when that movement is no longer restricted by a rigid boot.

Considered in aggregate, these findings suggest that: boots need to be redesigned to permit greater sagittal plane ROM at the ankle, somewhat like the articulated boot evaluated by Bruening et al; heels should be lowered or eliminated completely to place the ankle joint in a more neutral position; the new equipment should be strongly recommended for the newest generation of skaters, and made widely available for more experienced skaters interested in a change (experienced skaters will likely need to be retrained to utilize the full ankle joint ROM of which they are capable);17 and skaters should consider strengthening the muscles surrounding the ankle to compensate partially for reduced sagittal ankle support.

Table 1. Most common sources of chronic lower extremity injuries with treatment and prevention strategies

Table 1. Most common sources of chronic lower extremity injuries with treatment and prevention strategies

Injuries related to training volume. As mentioned previously, figure skaters now practice up to six hours per day, six days per week, for 11 months per year,4 with the majority of the time spent training jumps, spins, footwork, and lifts. Repeated microtrauma without sufficient rest periods has resulted in calluses to the foot, ankle, and skin over the Achilles tendon;10 Achilles tendinitis;8 and stress fractures to the fibula, tibia, and metatarsals.19 Training volume can also exacerbate the previously discussed consequences of a raised heel and rigid boot, further increasing forces absorbed by the Achilles tendon during jump takeoffs and landings.8 Bradley8 reported that many skaters develop Achilles tendinitis while trying to perfect a new jump, as this is a time when they are likely to repeat the same jump over and over.

Pecina et al19 studied self-reported stress fractures in 42 world-class skaters. Stress fractures in this group (most frequently present in the takeoff leg) occurred coincident with an increase in off-ice running, an increase in the number of jump attempts, or the introduction of triple jumps to skaters’ training and routines.

Treatment options for injuries related to training volume should include a limited jump count (five per hour, and no more than 10 per day), removal of the problematic jump from practice and competition, complete rest, strength and flexibility training, or a combination of these strategies. Coach and skater education regarding appropriate training loads as well as preseason strength and flexibility training for the plantar flexor muscles (i.e., gastrocnemius, soleus, and plantaris) are recommended prevention strategies.8

Injuries related to jump mechanics. Takeoff and landing mechanics during jumps have been implicated in the development of several chronic injuries. Chronic peroneal tendon subluxation is thought to occur in response to repeated “toe ins” with an inverted ankle, as is the case for flip and Lutz jumps.16 Some inversion is normal, but too much represents poor jump mechanics. Articular cartilage degradation in the foot and ankle may be the result of repeated landings with poor foot alignment (possibly due to foot and toe deformities).9 Navicular stress fractures commonly develop as a consequence of a pronated foot on Salchow takeoffs.16

While skater training is certainly an important contributor to sound jump mechanics, boot design also has a significant influence on jump mechanics. Haguenauer et al18 found that limited plantar flexion minimized the participation of the knee and caused a reorganization of the ankle–knee–hip interjoint coordination. This ultimately resulted in a decreased jump height. A lower jump height means that skaters will complete their rotation closer to the ice, and, as Lockwood and Gervais20 suggested, the resulting “collision type landing” increases the magnitude and intensity of the impact force absorbed by the lower extremity musculature.

Initially, complete rest may be the necessary first step in treatment. Foot orthoses may help correct or compensate for foot alignment issues. A significant portion of faulty jump mechanics may be solved with the aforementioned suggested changes in boot design. Coaches should emphasize a more vertical toe-in (perpendicular to the ice) for flip and Lutz jumps. Finally, a pronated foot is a necessary component to a Salchow takeoff. If pain persists the jump should be eliminated from practice and competition.

Injuries related to muscle inflexibility. In a comprehensive study of elite junior figure skaters, Smith et al21 found that up to 70% of the skaters had tight quadriceps, up to 35% had tight hamstrings, and up to 90% had tight iliotibial bands (male skaters were less flexible than female skaters for all three). Tight quadriceps, hamstrings, and iliotibial bands were indicated by a quadriceps-inhibited flexion angle of 10º or greater, a popliteal angle greater than 5º, and a positive Ober test, respectively (see Smith et al21 for detailed test protocols). Tight quadriceps were significantly associated with Osgood- Schlatter disease, patellar tendinitis, patellofemoral pain, or all of these, while tight hamstrings were associated with patello­femoral pain only. Importantly, 75% of skaters who improved their flexibility through regular off-ice stretching regimens eliminated anterior knee pain completely.

Treatment and prevention strategies should focus on off-ice flexibility training with an emphasis on the quadriceps and hamstrings.

General safety concerns

Neither skating facilities nor skaters are equipped with appropriate protective gear. Gymnasts, by comparison, practice new, potentially dangerous skills with mats, foam pits, and spotters. Even in competition, gymnasts perform their skills over protective mats in the presence of spotters. In contrast, when practicing or even learning a new skill, figure skaters for the most part just “go for it” without any additional protection. Some skaters will place a small pad in their skating apparel to protect their hip or buttocks during practice sessions. However, even though all skaters fall occasionally during competition, they don’t generally wear padding as it may restrict movement and alter appearance, which can impact the overall score negatively.22 In addition, though injuries have been caused by collisions with the sideboards,5,6 the ice surface boundary remains unpadded in practice and competition.

Figure 2. An example of a harness system found in most figure skating training facil- ities.

Figure 2. An example of a harness system found in most figure skating training facil- ities.

In some cases readily available protective gear is not used. For example, many training facilities provide a safety harness for learning new jumps or lifts (Figure 2), but most skaters do not use such equipment as it has many disadvantages. First, unlike natural jump entry and landing, which are curved, when the skater is harnessed, the jump entry and landing must travel along a straight line. Second, the approach is generally slower and abbreviated due to limited space. Finally, the point of harness attachment is on the back of the skater at the midthoracic region. This site of attachment causes an anterior lean of the vertical axis of the body and alters normal rotation. As a result of these disadvantages, a harness is rarely used. We advise the harness system be modified to permit a more natural skating path and axis of rotation.

A final consideration for safety and injury reduction concerns the asymmetry of freestyle and pairs skater skill elements. Like dancers, gymnasts, cheerleaders, divers, and aerial skiers, figure skaters almost exclusively rotate in one direction for all spins, jumps, and lifts (counter-clockwise rotations if right-handed and clockwise rotations if left-handed). The unidirectional rotation pattern promotes muscle strength imbalances, which may lead to performance decrements and even injury.16 Unlike any other jumping athlete, all required figure skating jumps are landed on one leg only, and it is the same leg each time (usually ipsilateral to the dominant arm). This creates repeated asymmetric shear and torsional forces at the sacroiliac joint of the supporting side (the sacrum is forced downward by the weight of the upper body, while the innominate bone is forced upward by the ground reaction force).16

The shear force and torsional asymmetry may be addressed both on and off the ice. On-ice training should place a greater emphasis on symmetric skating patterns and step sequences, like the required Moves in the Field2 patterns. Off-ice conditioning programs should aim to improve muscle imbalance through strategic exercises targeting unilaterally weak muscle groups.  Additionally, the introduction of off-ice nondominant rotations and landings may improve symmetry while also contributing to an improved on-ice performance.

Conclusion

Figure skating is a physically demanding sport that poses unique challenges for skaters, coaches, and medical professionals. Chronic lower extremity injuries are quite common in figure skaters of all ages and skill levels, and many are preventable. Most of these injuries are directly or indirectly related to boot structure and design, training volume, jump mechanics, muscle strength, muscle inflexibility, or a combination of these variables. Boots should be modified such that they are composed of entirely synthetic material, allow for enhanced sagittal ROM at the ankle, and reduce or completely eliminate the heel height. Training volume (especially jump count) should be monitored and appropriately limited, and training programs should emphasize off-ice functional strength enhancement and flexibility. Finally, skaters should be encouraged to wear protective gear, at least when practicing a new skill.

Relative to other artistic sports such as gymnastics and dance, figure skating is underrepresented in the scientific literature. Only with carefully designed and controlled randomized trials and longitudinal studies can we train and treat these athletes effectively.

Nathan W. Saunders, MA, is a former US singles and pairs figure skater and is currently a doctoral candidate in the Department of Health Sciences, Kinesiology Program, at The Ohio State University in Columbus, OH. Steven T. Devor, PhD, FACSM, is an associate professor of exercise physiology in the Department of Health Sciences, Kinesiology Program, and the Department of Physiology and Cell Biology at The Ohio State University.

REFERENCES

1. U.S. Figure Skating Fact Sheet. US Figure Skating website. http://www.usfigureskating.org/Content/FactSheet.PDF. Accessed January 20, 2013.

2. US Figure Skating. The 2010 Official Figure Skating Rule Book. Colorado Springs, CO: US Figure Skating; 2009.

3. Dubravcic-Simunjak S, Pecina M, Kuipers H, et al. The incidence of injuries in elite junior figure skaters. Am J Sports Med 2003;31(4):511-517.

4. International Judging System. US Figure Skating website. http://www.usfsa.org/New_Judging.asp?id=289. Accessed January 21, 2013.

5. Fortin JD, Roberts D. Competitive figure skating injuries. Pain Physician 2003;6(3):313-318.

6. Smith AD. The young skater. Clin Sports Med 2000;19(4):741-755.

7. Ehrenman G. Skating past injury.(input output). Mechanical Engineering-CIME. 2004;126(9).

8. Bradley MA. Prevention and treatment of foot and ankle injuries in figure skaters. Curr Sports Med Rep 2006;5(5):258-261.

9. Pelham TW, Holt LE, Stalker R. Soft tissue and articular cartilage injuries in the landing foot and ankle of young pre-national level figure skaters. Int Sports J 2001;5:51-59.

10. Lemasters GS. Skating injuries and their treatment. Can Fam Phys 1972;18(7):62-63.

11. Smith AD, Micheli LJ. Injuries in competitive figure skaters. Phys Sportsmed 1982;10(1):36-47.

12. Smith AD. Foot and ankle injuries in figure skaters. Phys Sportsmed 1990;18(3):73-86.

13. Luke AC, Micheli LJ. Ankle Swelling – Figure Skating. Med Sci Sports Exercise 1999;31(5):S87.

14. Anderson SE, Weber M, Steinbach LS, Ballmer FT. Shoe rim and shoe buckle pseudotumor of the ankle in elite and professional figure skaters and snowboarders: MR imaging findings. Skeletal Radiol 2004;33(6):325-329.

15. Brown TD, Varney TE, Micheli LJ. Malleolar bursitis in figure skaters. Indications for operative and nonoperative treatment. Am J Sports Med 2000;28(1):109-111.

16. Bruening DA, Richards JG. The effects of articulated figure skates on jump landing forces. J Appl Biomech 2006;22(4):285-295.

17. Fortin JD, Harrington LS, Langenbeck DF. The biomechanics of figure skating. Phys Med Rehabil 1997;11(3):627-648.

18. Pećina M, Bojanić I, Dubravcić S. Stress fractures in figure skaters. Am J Sports Med 1990;18(3):277-279.

19. Haguenauer M, Legreneur P, Monteil KM. Influence of figure skating skates on vertical jumping performance. J Biomech 2006;39(4):699-707.

20. Lockwood K, Gervais P. Impact forces upon landing single, double, and triple revolution jumps in figure skaters. Clin Biomech 1997;12(3):S11.

21. Smith AD, Stroud L, McQueen C. Flexibility and anterior knee pain in adolescent elite figure skaters. J Pediatr Orthop 1991;11(1):77-82.

22. Riney SM, Goldman SI, Moyer M, Johns J. Prevention of lateral hip injuries in competitive figure skaters. J Athl Train 1995;30(1):75-76.

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2 Responses to Over the Edge: Lower extremity injuries in figure skaters

  1. Great article- FYI, I’ve been putting orthotics in figure skates for the past 30 yrs. with fabulous success both for all sorts of overuse problems re feet, ankles, knees, & backs AS WELL as improved performance. Men’s Olympic Gold medalist, Evan Lysacek has been in orthotics since I first treated him at 10 yrs. old (go to website-click news articles, PODIATRY MANAGEMENT,”Figure Skating, Olympic Gold & Podiatry).
    My experience has been that all aspects of figure skating, including the emphasis on acrobatic jumping improves with proper orthotic control. As you’ll see in the Lysacek article, attention to alignment & foot mechanics is paramount- also functional training & strengthening of foot ankle & lower extremity structures.
    We’ve got a new book coming out this March authored by long time “Ask Mr. Edge” boot fitter John Harmata to which I contributed chapters on orthotics, & common foot problems , as well as the book’s forward. Title-“Anatomy of a Figure Skating Injury”(Infinity publishing)
    Looking forward to hearing from you guys!… Dr. Bob Weil

  2. Nathan W. Saunders, Ph.D. says:

    Congratulations on the new book, Dr. Weil! I’m always happy to see expansion of educational literature for the figure skating community. Now we just need skaters, coaches, and equipment manufacturers to access and utilize the material.

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