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Original Research

Difference in Agility, Strength, and Flexibility in Competitive Figure Skaters Based on Level of Expertise and Skating Discipline

Slater, Lindsay V.1; Vriner, Melissa2; Zapalo, Peter2; Arbour, Kat2; Hart, Joseph M.1

Author Information
The Journal of Strength & Conditioning Research: December 2016 - Volume 30 - Issue 12 - p 3321-3328
doi: 10.1519/JSC.0000000000001452
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Abstract

Introduction

Figure skating is an extremely difficult sport that requires a combination of grace, artistry, flexibility, speed, and power. Indoor training facilities allow for a continuous training season, with a long competitive season spanning from the end of the summer to the spring. Because skills become increasingly difficult in competitive skating, more figure skaters are engaging in strength and conditioning programs to gain the appropriate strength, agility, and flexibility necessary to complete the on-ice elements. Despite this increased involvement in strength and conditioning programs, there is no current information about differences in off-ice performance and strength based on skating level and discipline.

The sport of figure skating has evolved over the past decade with the introduction of a new international judging system that rewards the most difficult elements when athletes are most fatigued, which may increase risk of lower extremity and low back injuries. Injuries are routine in singles, pairs, and dance skaters (8,9,11), with back, knee, and ankle joint injuries most commonly reported (11). Although injuries are commonplace in all skating disciplines, previous researchers have noted differences in injury rates in elite junior singles, pair, and dance figure skaters (9), with low back injuries most common in singles skaters (13% of all injuries) and more injuries reported in junior skaters than senior skaters (8,9), supporting that skating disciplines and levels expose the body to different demands.

These differences may also manifest in off-ice performance measures. Although there is no information regarding performance measures in figure skaters, previous researchers have noted differences in strength, speed, and power based on level and position in football, tennis, rugby, soccer, and basketball (5,7,12,20,24,26,27). Differences in physiological characteristics based on sport and position drives different strength and conditioning goals and programs. Understanding disparities in physiological profiles of figure skaters in different disciplines may help sports performance professionals tailor strengthening programs to improve skating performance. Furthermore, appreciation for physiological differences may assist with injury-prevention programs such as neuromuscular training programs for preventing anterior cruciate ligament tears in female athletes (13,17). Skating level in this study was defined as highest test level and limited to the top 3 levels in figure skating (novice, junior, and senior). Therefore, the purpose of this study was to compare agility, strength, and flexibility performance based on skating discipline and level. We expect that senior level skaters will perform significantly better on agility and strength tasks compared with junior and novice skaters. We expect that ice dancers will perform significantly better on flexibility tasks compared with pairs, singles, and synchronized skaters.

Methods

Experimental Approach to the Problem

A descriptive, cross-sectional study was used to compare off-ice performance measures in figure skaters based on skating discipline and skating level. The independent variables in this study were skating discipline (singles, dance, pairs, and synchronized) and level (novice, junior, and senior). The dependent variables included agility, strength, and flexibility performance.

Subjects

A total of 347 athletes (age range = 10–33 years) between novice and senior levels of expertise volunteered to participate in the combine testing with United States Figure Skating Association (USFSA) in 2014 (Table 1). Subjects self-reported skating discipline (singles, ice dance, pairs, or synchronized skating). All subjects participated in a larger program designed by USFSA called the Standardized Testing of Athleticism to Recognize Skaters (S.T.A.R.S) and participants under the age of 18 completed the program with parental consent. All data were deidentified before sharing for statistical analyses and deemed exempt by the University of Virginia institutional review board for health sciences research. Four subjects did not complete all tests and were excluded from analyses.

Table 1
Table 1:
Participant demographics by skating discipline (singles, dance, pairs, and synchronized skating) and skating level (novice, junior, and senior).

Procedures

Subjects reported for a single testing session in athletic attire and athletic shoes. Mass, height, and leg length measurements were recorded before completing any testing. Subjects were barefoot for all anthropometric measurements. Leg length was defined as the distance from the greater trochanter to the floor (18). Subjects completed combine testing in the following order: hexagon test, t-test, maximal vertical jump test, alternating triple bound jump, tuck jumps, push-ups, v-ups, hand press, front split, seated reach, and stork pose. The hexagon and t-tests were implemented using the protocol described by the National Strength and Conditioning Association (NSCA) (3). The hexagon and t-tests have been shown to be reliable and valid (4,25,28). Maximal vertical jump height was measured as the distance from standing reach of the middle finger to the distance of the middle finger at peak jump height from a countermovement jump. Subjects used ink on the middle finger to identify both distances clearly on the wall, which has been used by previous researchers with high reliability (6,30). A tape measure was secured to the floor for alternating bounds. Subjects started with toes behind the tape measure and took 2 maximal single-foot leaps and landed the third leap on 2 feet. Takeoff foot for the first leap was standardized to the preferred on-ice takeoff foot. Subjects were required to stick the landing, and total measurement was recorded from the start of the bounds (zero) to the heel of the foot on the third jump landing. The timed tuck jump assessment included the number of tuck jumps completed in 30 seconds, similar to the time tuck jump test used previously (16). An elastic strap was placed at the subject's knee height with the hip and knee flexed to 90°. Only jumps that were equal to or higher than the elastic band were counted (Figure 1). Push-ups were completed with hands directly under the shoulders with fingers pointing forward and feet together. Subjects lowered his or her body until the upper arm was parallel to the floor, as previously described (22). Pace was set using a metronome so that it was a one second descend and one second ascend. Total consecutive push-ups at the preselected pace until fatigue were recorded. The bent knee v-up assessment was completed after push-ups. The subject lied supine on the floor with arms at the sides and legs extended and simultaneously raised the torso to approximately 90 degrees and bent the knees toward the chest. The subject returned to full supine position between repetitions. Total completed repetitions in 30 seconds were recorded.

Figure 1
Figure 1:
Tuck jump assessment for figure skaters. Subjects completed as many tuck jumps as possible in 30 seconds with knees above the elastic strap.

The hand press, front split, seated reach, and stork were completed barefoot. The subject sat on the floor with legs extended and abducted in a “V” position for the hand press. Subjects were asked to place palms flat on the floor with fingers pointing forward and lift their body and legs off the floor. Total time was recorded with heels raised above the floor (Figure 2). The front split was completed next to a 6-foot tape measure secured to the floor. The subject lowered into a full-split position with the preferred spiral skating leg forward and the free leg behind and externally rotated. Total distance from the front leg lateral malleolus to the rear leg (opposite leg) lateral malleolus was measured using the tape measure on the floor (19). The seated reach was implemented according to the protocol described by the NSCA (3). Previous researchers have noted good reliability for the sit-and-reach assessment (2). The stork position was completed with the landing leg on the floor with the free foot pressed against the knee of the standing leg with the heel above the knee and arms extended above the head with hands clasped (Figure 3). Once subjects were in the proper position, they were asked to close their eyes. Time started as soon as the subject closed their eyes and was stopped if the subject lost balance, broke position, or opened their eyes. Previous researchers have found the stork pose to be a reliable test for balance (1). Subjects were stopped if they balanced for longer than 2 minutes. Time was recorded using a stopwatch.

Figure 2
Figure 2:
Hand press performance test. Subjects were asked to lift their legs and body off the floor. Total time was recorded with legs, body, and heels raised above the floor.
Figure 3
Figure 3:
Stork pose performance test. Subjects were asked to stand with the landing leg on the floor with the free foot pressed against the knee of the standing leg with the heel above the knee and arms extended above the head with hands clasped. Total time was recorded while holding this position with the eyes closed.

Statistical Procedures

Three separate multivariate analyses of variance were performed on groupings of dependent variables (agility, strength, and flexibility) to investigate differences between level of expertise and skating discipline. Agility included the hexagon jump, t-test, triple bounding, and tuck jumps. Strength included the vertical jump, push-ups, v-ups, and hand press. Flexibility included the front split, seated reach, and stork hold. The independent variables included skating level (senior, junior, and novice) and skating discipline (singles, dance, pairs, and synchronized skating). Post hoc testing was performed using Scheffe's test. Alpha level was set at α ≤ 0.05 a priori. Pillai's trace p-values were reported for all tests because of unequal sample sizes. All statistical tests were run using SPSS (Version 22, Chicago, IL, USA). Mean differences (MDs) and Cohen's d effect sizes with 95% CIs were calculated for all significant differences. Differences were not considered statistically significant when the effect size CI crossed zero. The vertical jump was normalized by height. The triple bounding, front split, and seated reach were normalized by leg length.

Results

There were significant differences in age, mass, and height based on level, however, there were fewer differences based on discipline. Singles skaters weighed less than pair skaters (MD = −7.40 kg [CI: −12.33, −2.47]; p = 0.02, d = −0.69 [CI: −1.15, −0.23]) and synchronized skaters (MD = −6.50 kg [CI: −8.89, −4.11]; p < 0.001, d = −0.74 [CI: −1.02, −0.46]). Singles skaters were also shorter than dancers (MD = −4.30 cm [CI: −7.59, −1.01]; p = 0.034, d = −0.43 [CI: −0.76, −0.10]) and pairs skaters (MD = −6.50 cm [CI: −10.78, −2.22]; p = 0.016, d = −0.70 [CI: −1.16, −0.23]). Only singles and synchronized groups were significantly different in age (MD = −1.00 years [CI: −1.70, −0.30]; p = 0.014, d = −0.39 [CI: −0.66, −0.12]). All demographic data are presented in Table 1.

Agility

Singles skaters completed the hexagon jump test faster than synchronized skaters (MD = −1.40 s [CI: −2.19, −0.61]; p = 0.003, d = −0.48 [CI: −0.76, −0.21]; Table 2). Senior and junior skaters completed the hexagon jump test faster than novice skaters (p ≤ 0.05, MDsenior = −1.44 s [CI: −2.29, −0.59], dsenior = −0.49 [CI: −0.79, −0.20]; MDjunior = −0.70 s [CI: −1.40, 0.00] djunior = −0.24 [CI: −0.48, 0.00]; Table 2). Singles, dance, and pair skaters completed the t-test faster than synchronized skaters (p < 0.001, MDsingles = −1.10 s [CI: −1.37, −0.83], dsingles = −1.10 [CI: −1.39, −0.81]; MDdance = −1.00 s [CI: −1.30, −0.70], ddance = −0.91 [CI: −1.20, −0.63]; MDpairs = −1.20 s [CI: −1.63, −0.77], dpairs = −1.17 [CI: −1.60, −0.73]; Table 2). Senior skaters completed the t-test faster than novice skaters (MD = −0.38 s [CI: −0.74, −0.02]; p = 0.001, d = −0.31 [CI: −0.60, −0.01]; Table 2). Singles, dance, and pair skaters jumped farther than synchronized skaters in the triple bound jump (p < 0.001, MDsingles = 1.00 [CI: 0.73, 1.27], dsingles = 1.03 [CI: 0.74, 1.32], MDdance = 0.80 [CI: 0.50, 1.10], ddance = 0.75 [CI: 0.47, 1.04], MDpairs = 1.40 [CI: 0.92, 1.88], dpairs = 1.24 [CI: 0.80, 1.68]; Table 2). There were no significant differences between level of skaters and performance on the triple bound jump. Singles skaters completed more tuck jumps in 30 seconds than synchronized skaters (p = 0.001, MD = 6.40 [CI: 3.12, 9.68]; d = 0.53 [CI: 0.26, 0.81]; Table 2). Senior and junior skaters completed more tuck jumps in 30 seconds than novice skaters (p < 0.01, MDsenior = 6.85 [CI: 3.10, 10.60], dsenior = 0.53 [CI: 0.24, 0.83], MDjunior = 4.29 [CI: 1.32, 7.26], djunior = 0.35 [CI: 0.11, 0.59]; Table 2). There was a significant interaction (p = 0.021) between level and discipline in tuck jump performance, with senior synchronized skaters completing more tuck jumps than senior dancers (MD = 7.20 [CI: 1.41, 12.99]; d = 0.73 [CI: 0.14, 1.32]), however, junior dancers completed more tuck jumps than junior synchronized skaters (MD = 5.30 [CI: 1.06, 9.54]; d = 0.50 [CI: 0.10, 0.91]; Table 2).

Table 2
Table 2:
Mean and standard deviation for agility performance by skating discipline (singles, dance, pairs, and synchronized skating) and skating level (novice, junior, and senior).

Strength

Singles, dance, and pair skaters jumped higher (normalized to leg length) on the vertical jump test compared with synchronized skaters (p < 0.001, MDsingles = 0.02 [CI: 0.01, 0.03], dsingles = 1.00 [CI: 0.71, 1.29], MDdance = 0.03 [CI: 0.02, 0.04], ddance = 1.50 [CI: 1.19, 1.80], MDpairs = 0.03 [CI: 0.02, 0.04], dpairs = 1.40 [CI: 0.96, 1.84]; Table 3). There was no difference in vertical jump performance based on level. Dancers completed more push-ups than singles skaters (p < 0.001, MD = 7.00 [CI: 3.36, 10.64]; d = 0.63 [CI: 0.30, 0.97]; Table 3) and synchronized skaters (p < 0.001, MD = 11.90 [CI: 9.06, 14.74]; d = 1.17 [CI: 0.87, 1.47]; Table 3). Singles completed more push-ups than synchronized skaters (p = 0.006, MD = 4.90 [CI: 2.19, 7.61]; d = 0.49 [CI: 0.22, 0.77]; Table 3). Senior and junior skaters completed more push-ups than novice skaters (p < 0.01, MDsenior = 5.39 [CI: 2.17, 8.61], dsenior = 0.49 [CI: 0.19, 0.78], MDjunior = 3.71 [CI: 0.94, 6.48], djunior = 0.32 [CI: 0.08, 0.56]; Table 3). Singles and dance skaters completed more v-ups in 30 seconds than synchronized skaters (p ≤ 0.05, MDsingles = 2.80 [CI: 1.20, 4.40], dsingles = 0.48 [CI: 0.20, 0.75], MDdance = 2.40 [CI: 0.80, 4.00], ddance = 0.42 [CI: 0.14, 0.70]; Table 3). Senior and junior skaters completed more v-ups than novice skaters (p = 0.006, MDsenior = 2.62 [CI: 0.84, 4.40], dsenior = 0.43 [CI: 0.14, 0.72], MDjunior = 2.19 [CI: 0.79, 3.59], djunior = 0.38 [CI: 0.14, 0.62]; Table 3). Singles and dance skaters held the hand press longer than synchronized skaters (p ≤ 0.05, MDsingles = 3.30 s [CI: 1.96, 4.64], dsingles = 0.67 [CI: 0.39, 0.95], MDdance = 2.20 s [CI: 0.89, 3.51], ddance = 0.47 [CI: 0.19, 0.75]; Table 3). There were no differences in hand press performance based on level.

Table 3
Table 3:
Mean and standard deviation for strength performance by skating discipline (singles, dance, pairs, and synchronized skating) and skating level (novice, junior, and senior).

Flexibility

Pair skaters had a greater front-split distance than dance (p = 0.024, MD = 0.09 [CI: 0.04, 0.14]; d = 0.83 [CI: 0.36, 1.30]) and synchronized skaters (p = 0.009, MD = 0.09 [CI: 0.03, 0.15]; d = 0.64 [CI: 0.21, 1.06]; Table 4). There were no differences in front-split distance based on level. Singles and pair skaters had a greater reach distance in the seated reach than dancers (p ≤ 0.05, MDsingles = 0.10 [CI: 0.06, 0.14], dsingles = 0.87 [CI: 0.53, 1.21], MDpairs = 0.09 [CI: 0.03, 0.15], dpairs = 0.72 [CI: 0.25, 1.19]; Table 4). Singles also had a greater reach than synchronized skaters (p = 0.007, MD = 0.06 [CI: 0.03, 0.09]; d = 0.50 [CI: 0.22, 0.78]; Table 4). There was no difference in seated reach distance based on level. Dancers held the eyes closed stork pose longer than singles (p = 0.013, MD = 10.73 s [CI: 3.53, 17.93]; d = 0.49 [CI: 0.16, 0.82]) and pair skaters (p = 0.013, MD = 16.47 s [CI: 4.76, 28.18]; d = 0.65 [CI: 0.19, 1.12]; Table 4). There were no differences in stork performance based on level.

Table 4
Table 4:
Mean and standard deviation for flexibility by skating discipline (singles, dance, pairs, and synchronized skating) and skating level (novice, junior, and senior).

Discussion

The results of this study support that performance on agility, strength, and flexibility tasks vary based on skating discipline and level. Senior and junior skaters tended to be faster and stronger than novice skaters, however, there were no differences in flexibility between the three levels. Singles, dance, and pair skaters tended to be more agile, stronger, and flexible than synchronized skaters, however, senior synchronized skaters tended to be more agile than senior skaters in other disciplines. Singles skaters and ice dancers tended to be stronger than pair and synchronized skaters.

Senior skaters performed better than novice skaters on the hexagon jump, t-test, and tuck jumps, supporting our hypothesis that senior figure skaters would perform better than novice skaters on agility tasks. The hexagon and t-tests are often used to measure agility and have been shown to be reliable and valid (4,25,28). Agility may improve with level of expertise because of increased difficulty of jumps, footwork sequences, and transitions in skating programs. Similar findings have been noted in tennis, with better players displaying enhanced agility (27). High performers have increased reactive ability (29) which may contribute to increased agility with greater sport expertise. These differences may also be due to the physical maturation associated with the older athletes in the higher levels. Although singles, pair, and dance skaters tended to be more agile than synchronized skaters, senior synchronized skaters outperformed other senior skaters on the timed tuck jump test (Table 2). This may indicate that novice and junior synchronized skaters need to be participating in conditioning programs that focus on developing agility and endurance so that these skaters are better prepared for senior synchronized skating programs.

Similar trends were noted on v-ups, with singles and dance skaters performing more bent knee v-ups in 30 seconds than synchronized skaters (Table 3). The v-up movement pattern was very similar to the tuck jump motion and may require increased rectus femoris activation rather than pure abdominal recruitment (10). Furthermore, there is a weak relationship between isokinetic abdominal strength and performance on a timed sit-ups test (14). Future research investigating differences in abdominal strength in figure skaters should use a valid and reliable test that isolates and recruits more abdominal musculature to assess core strength. Senior and junior skaters also performed more push-ups than novice skaters, with senior and junior dance and pair skaters performing the most push-ups (Table 3). Although figure skating requires predominantly lower-body strength, dance and pair skating includes complex lifts, requiring both partners to have enough upper-body strength to hold the positions. Strength and conditioning coaches should include upper-body strengthening in programs for dance and pair skaters.

Although singles, dance, and pair skaters had greater vertical jumps compared with synchronized skaters, there was no difference in level for vertical jump performance. Previous researchers comparing jump technique between a single, double, and triple jump did not find a difference in jump height (21), supporting the lack of difference in vertical jump height between novice, junior, and senior skaters in this study. Therefore, power development may be necessary for singles, dance, and pair skaters in all levels to assist with on-ice jump technique. Synchronized skaters may require different types of power and strength development considering most high-level teams do not include jumps in programs making vertical jump height less important.

There were no differences in flexibility based on level; however, singles and pair skaters demonstrated the greatest flexibility. Singles and pair skating may require greater flexibility to perform grab spins and lifts in full-split position. Although all skating disciplines require some degree of flexibility, only singles and pair skaters demonstrated increased hamstring flexibility on the seated reach test (23). This is particularly concerning given the increased risk of overuse injury associated with decreased hamstring flexibility (15,31). Overuse injuries are extremely common in figure skating and recovery time can range from 5 weeks to 18 months (9). Sports medicine and performance professionals working with figure skaters should consider hamstring flexibility for skaters to encourage good lower extremity and low back flexibility. Future research with figure skaters should consider assessments that isolate hamstring and low back flexibility. Singles and pair skaters may have increased lumbar flexibility, which may have contributed to the increased reach distance.

There were some limitations in this study. The subjects in this study did not report number of years spent skating, therefore only skating level was used to separate level of expertise rather than a combination of years spent skating and skating level. This assumes a young skater who quickly moved up to the senior level is comparable to an older skater in the same discipline who has competed at the senior level for multiple years. Although this assumption does not allow for the consideration of the effect of physical maturation on performance measures, these data best represent the competitive skating population where young skaters may compete against older, more mature skaters solely dependent on skating abilities and level. Another limitation in this study was the use of multiple assessors to score these tests. The tests used in this study have good interrater reliability, therefore limiting the influence of multiple assessors. Furthermore, all assessors were trained similarly and were monitored by a certified strength and conditioning coach with at least four years of experience testing this population. Future research evaluating off-ice performance in figure skaters should use fewer assessors to minimize variability.

In conclusion, senior and junior skaters tended to have better agility and strength compared with novice skaters and singles, dance, and pair skaters tended to have better agility, strength, and flexibility compared with synchronized skaters. Strength and conditioning professionals should consider skating discipline when designing programs.

Practical Applications

The results of this study support that performance on agility, strength, and flexibility tasks varies based on skating discipline and level. Senior and junior skaters tended to be faster and stronger than novice skaters. Singles, dance, and pair skaters tended to be more agile, stronger, and flexible than synchronized skaters, however, senior synchronized skaters tended to perform better than senior skaters in other disciplines. These results support that skaters should have different strength and conditioning programs based on discipline and level. Furthermore, these data help establish normative values for figure skaters, which may help guide sports performance professionals when designing individualized strengthening programs and injury-risk prevention programs in figure skating.

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Keywords:

sports performance; figure skating; youth sports; injury

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