Introduction: The cartwheel is a very common, basic gymnastics skill. It starts from a sideways position with the arms extended above the head (1). From this position, the performer proceeds through a side scale and continues rotating sideways about the hip joint of the supporting leg until the hand comes in contact with the mat (1). Body weight is transferred onto the lead arm and the lead leg simultaneously begins to rotate sideways about its hip joint (1). This brings the performer to a straddled-split position in a handstand (1). The second half of the skill is essentially a mirror image of the first half.

Proficiency in gymnastics skills is dependent upon a variety of factors. One of the most important factors in the cartwheel is called "internal amplitude", which focuses on the range of motion within the joints of the body (1). A greater internal amplitude is not only more aesthetically appealing but also has functional value (1). Weight transfer is much easier and smoother if the arms can be placed closer to the leg on the floor at the beginning of the movement, thus there is greater hip range of motion (1). The same relationship applies for the end of the motion where the foot touches down after the handstand position (1).

Another important factor in proficient performance of the cartwheel has to do with segmentation (1). Essentially, any body shape that forms a straight line is termed a segment (1). The fewer number of segments used, the more proficient the skill is being performed (1).

The purpose of this analysis was to compare the proficiency of the first half of the skill to that of the second half. Symmetry of movement is very important in the sport of gymnastics, contributing greatly to the aesthetic appeal of the sport. The movement was analyzed for internal amplitude (hip range of motion) and segmentation (knee and elbow flexion).

Methods: A skill analysis of the cartwheel was performed using a Panasonic SVHS VCR AG-7350 (Matsushita Electric Industry Company Limited, Japan) and then captured and digitized on a personal computer (PC) using the Human Movement Analysis Version 2 (HU-M-AN) Program at Acadia University, Wolfville, NS. The female subject (age = 22 years, wt. = 60kg, ht. = 178cm) performed five trials of a complete cartwheel in a single session, with the most accurate trial being used for the analysis.

Initially, athletic tape markers were placed on the subject around the malleoli and femoral condyles of both the right and left legs; around the distal radio-ulnar joints, the epicondyles of the humerus, and the acromions of both arms; on both anterior and posterior superior iliac spines; on the sternoclavicular joint; and on both mastoid processes. The subject wore a tight spandex body suit to maximize the efficiency of the analysis. The skill was then performed in the sagital plane and recorded on video. The next step was to capture the selected trial of the skill on a PC. Once this was done, the skill was digitized using the HU-M-AN Program. Finally, a kinematic analysis was done by the HU-M-AN Program to determine the proficiency of the skill.

Results: Analysis of the movement showed a lack of symmetry in internal amplitude of the hip. The hip angles for the first half (phase 1) of the cartwheel were not consistent with that of the second half (phase 2) of the cartwheel (see Figure 1).

The movement was also analyzed for segmentation, comparing phase 1 of the cartwheel to phase 2. Segmentation was consistent for the entire cartwheel with respect to the legs; the subject’s legs remained straight throughout. However, there was more segmentation in phase 2 of the cartwheel with respect to elbow flexion (see Figure 2).

Also, the movement was not symmetrical in terms of internal amplitude of the hip joint. Phase 1 of the cartwheel had 20% more internal amplitude thus was the more proficient half of the cartwheel (see Figure 3).

The cartwheel was symmetrical in other respects. The displacement of the center of gravity in the x-direction was a linear relationship. The displacement of the center of gravity in the y-direction created a symmetrical W-shape. These observations show phase 1 and 2 to be similar in their properties of displacement. Likewise, there was a relatively consistent acceleration throughout the movement.

Conclusion: The cartwheel performed was more proficient in phase 1 of the movement. In phase 1 there was greater internal amplitude and less segmentation, both important factors in proficiency of movement. The movement was symmetrical in leg segmentation, acceleration, and displacement.