Sport Science: How Body Alignment Plays an Important Role in Performance and Injury Prevention

MAKING THE CONNECTION

How Body Alignment Plays an Important Role in Performance and Injury Prevention

BY LEE CABELL, EDD, MFF; PATTI LARKIN, CO(R), C.PED.; ELLEN GEMINIANI, MD

Body alignment

What is a proper posture? Being told to “stand up straight” may sound like a cliché, but optimal placement of the body parts is very important. Proper body alignment puts less stress on the joints and gives confidence to carry your body upright. Improving posture will likely take some time and conscious effort, and it is essential in figure skating.

Correct body alignment always comes from the basic, neutral, and anatomical position where the body is divided into three cardinal planes. Alignment refers to how the head, shoulders, spine, hips, knees, and ankles relate to and line up with each other.

The upper leg, lower leg, and feet should all line up in the same plane; specifically, there is a relationship between the hip, knee, and ankle joints. The feet need to be always in alignment with the knees.

First, we assess the pelvis, leg, and foot alignment (FIGURE 2).

During the single-leg squat assessment, the lumbo/ pelvic/hip complex, and knee and ankle should remain in a neutral position. The knee should remain in line with the foot, and the foot should be pointed straight ahead

Figure 2A: Correct alignment

(FIGURE 2A). Every time you bend your knees, make sure they are over your toes and never let them roll inwards. Feet must never be more turned out than your knees. The hip controls the knee and the foot, and the foot informs the hip what is happening.

How do we achieve this lower body alignment? First, figure skaters should focus on the correct alignment of each foot at the ankle and always hold this alignment correctly until it becomes second nature.

Figure 2B: "Knocked" knee

Figure 2C: "Knocked" knee = knee valgus

See complete diagram in printed PS Magazine and www.skatepsa.com/ps-magazine

The most common cause of figure skating injuries to the lower legs, feet, and ankles is that figure skaters fail to keep their feet and legs aligned. Even slight misalignment will cause a weakening of the joints involved and, in the end, an imbalance in the muscle groups of the lower leg. Weaknesses in the skater’s hips will always show up in the lower legs. It starts with the muscles around the hip (gluteus medius and gluteus maximus), continues through the “knocked” knee, and ends with a dropped ankle (pronation) (FIGURE 2B) or “knee valgus” (FIGURE 2C) The same analogy can be demonstrated on jump landings (FIGURE 3). Notice the correct hip, knee, and ankle alignment (FIGURE 3A) and the joints’ misalignment (FIGURE 3B).

Figure 3A: Correct alignment

Figure 3B: Joints' misalignment

Foot and ankle

The ankle joint (also known as the upper ankle) serves as the articulation between the foot and leg. The ankle joint is comprised of three bones (tibia, fibula, and talus) (FIGURE 4) and is designed to absorb shock and provide proprioception (the body’s ability to know where it is in space). The ankle joint range of motion is approximately 70 degrees in plantar and dorsiflexion. Skaters need as much ankle mobility as possible to perform the explosive jump elements and to absorb shock forces. If athletes have limited ankle mobility, e.g., tight calves (tight heel cord) or their skating boots are too stiff, the ankle mobility will be restricted. This will impede progress and prevent the ankle from absorbing the shock forces imposed on the body. The foot is a complex and flexible structure making up about a quarter of the total bones found in the human body. The foot absorbs and transforms forces while maintaining whole-body stability and utilizes elastic energy for efficiency during jump take-off and landing. With 26 bones, 29 muscles, 33 joints, 100 ligaments, tendons, and a network of blood vessels, nerves, and other soft tissue in each foot, there is so much motion going on inside the skate that can impact the skater’s every move.

Figure 4: Ankle joint

See complete diagram in printed PS Magazine and www.skatepsa.com/ps-magazine

However, once skaters lace up their skates and are out on the ice, movement of the foot and ankle are not visible and therefore cannot be observed. Identifying and understanding any improper foot and ankle mechanics may provide coaches insight into what motions are occurring inside the boot. This will help skaters maximize their potential and reduce their risk for injuries and long-term foot and ankle problems.

Ideally, the bones, ligament, muscles, tendons, and fascia of the foot form the arch height, strength, and the ability to resist deformity because of external forces. The arch acts as a beam and is elevated through a mechanism of plantar fascia (FIGURE 5). The plantar fascia is a strong and inelastic band of connective tissue located in the sole of the foot and has the major role to support the longitudinal arch. It creates a truss-like rigid structure (FIGURE 6). When skaters bend their ankle, the hind foot (heel) rotates in slightly, thereby “unlocking” the middle of the foot allowing the foot to pronate. Pronation is a desirable motion of the foot where the foot becomes adaptable to the environment and helps the foot and body absorb shock. The rear foot and forefoot are held together by the plantar fascia, and the suitable amount of pronation would be expected during weight bearing. (Neumann, 2017)

Figure 5: The beam model of the longitudinal arch

See complete diagram in printed PS Magazine and www.skatepsa.com/ps-magazine

Note: The arch is a curved beam consisting of interconnecting joints and supporting plantar ligaments. Tensile forces (t) are concentrated on the lower beam surface; compressive forces (c) are generated at the upper surface. W = weight

Figure 6: The truss model of the longitudinal normal arch

See complete diagram in printed PS Magazine and www.skatepsa.com/ps-magazine

As the heel lifts, the foot mechanics reverse. This is called supination. The tightening of the plantar fascia raises the longitudinal arch, making it ready for jump takeoff (Levangie & Norkin, 2011). This foot arch acts as a second-class lever mechanism when the fulcrum (axis) is at the toes. Now, the foot is more rigid and stable at jump takeoff, the skater can effectively press down for “pushing off” at jump takeoff; the foot supinates and generates the forces responsible for propelling the skater’s body into the air (FIGURE 7A). Insufficient “push off” is evident from a fallen arch foot (FIGURE 7B).

Figure 7A: Normal foot

See complete diagram in printed PS Magazine and www.skatepsa.com/ps-magazine

Figure 7B: Foot with pes planus

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Figure skaters land their jumps on the toe pick first, i.e., landing is made first with the forefoot and then with the rearfoot while balancing on a 3/16-inch-wide blade.

A normal foot provides sufficient stability and mobility for the foot to be effective during jump takeoff and landing, absorbing high-impact forces exerted by a skater, similar to the way a car’s springs act when the car hits a bump.

Unfortunately, not all feet function ideally, and many athletes possess different foot dynamics that greatly affect their function and performance.

Flat feet (fallen arch)

All humans are born with flat feet and, through normal childhood development, will form the natural arches of their feet. However, some individuals fail to develop their arch resulting in fallen arches, commonly known as “developmental flat feet” — pronation (FIGURE 8). Often, flat feet are inherited, but some may acquire it through nerve issues, damaged tendons, or from an injury. Flat feet tend to be hypermobile and can be very inefficient. Many physical activities such as figure skating or activities that require propulsion, power, stability, and speed can be challenging to those who possess flat feet. A flat foot does not give the skater the necessary lever, thereby decreasing jump height. Skaters with this foot type may have an increased risk for foot and ankle injuries like stress fractures and tendonitis.

Overpronation

Flattening of feet is a natural movement of the foot that occurs during foot landing while running, walking, or landing a jump. Overpronation, on the other hand, is an excessive and undesirable motion of the foot resulting in an overly flattened foot. The arch collapse displaces the joints and muscles not only just in the foot, but also in the legs as well. Impact forces also produce a large amount of stress in the joints of the lower limbs which can be a determinant of injury (Bressel & Cronin, 2005). Acuña et al. (2014) measured high vertical impact forces with a special sensor mounted to skaters’ blades and reported that the forces were up to 5-8 times body weight. All this happens within 50-125 milliseconds—not much time to absorb these high-magnitude forces.

Figure 8

Figure 8

See complete diagram in printed PS Magazine and www.skatepsa.com/ps-magazine

Note: Intrinsic foot muscles are in the foot itself provide dynamic foot support. Extrinsic muscles are the larger muscles which control the movement of the foot.

A common condition in many figure skaters, overpronation makes maintaining blade alignment more difficult, increases boot fitting issues, impedes progress, and indirectly leads to potential injuries. With uncorrected pronation, the feet will collapse into the side of the skate, and the foot will press up hard onto the wall of the boot. Not only does this create pain and discomfort, but joints are also out of alignment. If the joints are out alignment, so are the muscles. As a result, the body will compensate with the “wrong” muscles over time and with impact forces from jump landings, injury to the foot and ankle may occur. Skaters may also experience problems in the knee, hip, and even the spine.

Performance can also be compromised. Skaters must be able to hold an outside edge all throughout the takeoff. Once skaters bend their skating knees right before takeoff, the arch will automatically pronate. If skaters overpronate, the arch will collapse inwardly forcing the blade onto the inside edge thereby “flutzing” the jump. Preventing arch collapse and holding the foot in a well-aligned position in the skate is imperative to maintain the desired blade alignment. If not, a skater may overcompensate elsewhere to maintain the outside edge.

Painful pressure spots, blisters, and calluses on the navicular bone (arch bone) and inside ankle bone are strong indications that the foot is overpronating. If the foot is pressed hard up against the inside of the boot, that excessive pressure from the collapsed arch puts undo stress on the boot contributing to early loss of boot support (FIGURE 9).

Figure 9

A common misconception is that the boot is defective or that the skater is “super strong” and constantly breaks down boots. Although it could be possible that a skater purchased a skate that lacked the appropriate support for their individual body dynamics, it is more than likely that the boot was not defective, and it was underlying faulty body mechanics that contributed to the untimely loss of boot support. Skating boots are designed to maintain a correctly aligned foot and ankle position but were never designed, nor should be used, to correct any faulty foot mechanics.

Unfortunately, if overpronation (as well as other body alignment issues such as weak hip and core) are not recognized and actively addressed, skaters may inadvertently be fit with a stronger boot to provide more “support” to offset the alignment problems. However, boots that are too strong for that individual can restrict the necessary joint mobility to perform proficiently. Also, if ankle joint movement is inhibited in the ankle (either internally such as a skater with tight heel cords or externally with a boot that is too stiff or restrictive), the forces from any impact will not be absorbed by the ankle joint effectively but be transferred to joints such as the foot, knees, hips, and spine, placing excesses stress on areas of the body that are not necessarily able to handle the shock load. This vicious cycle is all too common in figure skating and, if body alignment issues are not addressed and corrected, not only can slow or stall process, but can certainly lead to unwanted injuries, as well.

High-arched (hollow) feet

High-arched feet is a condition where the arches are unnaturally high, putting extra pressure on the ball and heel of the foot when ice skating (FIGURE 10). High-arched feet tend to roll outwards (oversupinate), which can lead to ankle instability and the increased risk of lateral ankle sprains. Also, those with very high arches, tend to “under pronate” and thereby do not absorb shock through the joints efficiently. Skaters with high arches will have a high instep so they must be fit with a boot that will accommodate this high-volume foot. Those whose boots do not accommodate their high instep may have tongue issues and have an increased risk of lace bite (because they need to pull their tongue so tight). Although not necessarily a tongue issue, their foot may pop out of the top of the boot so they may need to excessively tighten down their tongue to close the boot.

Figure skaters with high arches should pay extra attention to their lower limbs. This foot type can be prone to tendonitis and injuries of the knees and hips due to poor shock attenuation.

Figure 10: High-arched feet (oversupination)

Orthotics

Compare the foot to the foundation of a building or the tires of a car. When the foundation settles, the house cracks. Orthotics are like jacking up that side of the house that sagged and putting a shim in to level it. When the tires of the car go out of alignment, the front-end shimmies and may pull to one side and the ball joints wear out. The tires also wear out faster. The same is true of feet. They not only wear out faster, but they throw the rest of the body out of alignment in the process.

How do skate orthotics help?

Skate fitting professionals, sports medicine physicians, and coaches are turning to foot orthotics to help restore and maintain correct arch and foot alignment within the skating boot. Foot orthotics work in conjunction with the boot to lift the arch and realign the foot to a functional position, thereby promoting joint and muscle efficiency (FIGURE 11). Reducing overpronation will greatly limit the foot from collapsing against the side of the boot, prolonging boot wear and potentially preventing the skater from being fit with a boot that is too strong for them because previous boots broke down too soon. Better blade alignment and boot comfort are positive feedback often reported by skaters properly fitted with orthotics. Those with high arches will benefit from orthotic devices as well to support their high arches, cushion the foot, and stabilize the ankle to prevent the ankles from rolling out. Regardless of the skater’s foot dynamics, whether overpronation or oversupination, once the foot is more neutrally balanced within the boot, blade alignment should be improved.

Figure 11A: Overpronation without orthotics

Figure 11B: Overpronation with orthotics

Foot orthotics may take time to get used to and skaters may experience discomfort in the arch. A common mistake is to remove the orthotics and dismiss them as not working. The skater/parent/fitter can’t see what’s going on inside the boot and assume the discomfort is problematic and that the orthotics don’t work. But quite the opposite is true. Orthotics hold the foot into corrected position (usually a different position than the skater is accustomed to) and the foot structure may react and feel uncomfortable as a result. This is normal and expected. If a skater is uncomfortable, they can return to their fitting professional for a comfort adjustment or consult a physician for further pain evaluation.

References

Bressel E., & Cronin J. (2005) The Landing Phase of a Jump: Strategies to Minimize Injuries. Journal of Physical Education, Recreation & Dance 76(2), 31-47.

Acuña, S., Smith, D., Robinson, J., Hawks, J., Starbuck, P., King, D., Ridge, S., & Charles, S. (2014). Instrumented figure skating blade for measuring on-ice skating forces. Measurement Science and Technology, 25(12).

Lavangie, P., & Norkin, C. (2011). Joint structure and function. Philadelphia: F.A. Davis.

Neumann, D.A. (2017). Kinesiology of the musculoskeletal system; Foundations for Rehabilitation. St-Louis, MO: Saunders Elsevier.