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Introduction:

Kayak propulsive force is influenced by athletes’ anthropometric features as well as physiological, biomechanical, and neuromuscular factors. Previous studies suggest trunk and leg movements during kayak paddling to be important for creating force at the paddle and thus increasing performance.

It is thought that the asymmetrical leg movement helps the pelvis to rotate leading to an increased trunk rotation that allow the forces created by the leg muscles to be transformed to propulsive force at the paddle and thus have a positive impact on performance.

However, few biomechanical studies are available on para-kayak athletes. 

Study aim:

1) To examine the differences and similarities in kinematic and kinetic performance variables between para-kayak athletes with a unilateral above knee (AK) or below knee (BK) amputation during kayak ergometer paddling at a race pace intensity.

2) To, where possible, examine differences between the amputated (A) side and the non-amputated (NA) side. 

Methods:

Seventeen international level competitive para-kayak athletes (11 AK and 6 BK) performed paddling on a kayak ergometer. Athletes paddled on four different levels for 20 seconds each; 90, 100 and 110 strokes*min⁻¹ and at 150 W (females) or 200 W (males).

Thereafter, athletes paddled on a race pace intensity level corresponding to the intensity of a 200 m race. The race pace intensity was performed by the athletes first successively increasing their intensity for 10 stroke cycles (catch to catch of the same side) and then paddling at their race pace intensity for 10 stroke cycles.

3D kinematic and kinetic data were collected for the body, seat, footrest, and paddle during kayak ergometer paddling.

Main findings:

• No main effects for either side or group were seen for any of the paddle variables; power output, mean paddle force, maximal paddle force, paddle work, paddle impulse, maximal paddle velocity, cycle time, time to peak paddle force and drag length.
• Differences between the two groups were only seen in hip flexion/extension ROM, hip flexion and extension angular velocity and in hip flexion moment, where BK demonstrated larger values.
• Significant differences between the A and NA sides were observed in maximal, minimal, and mean posterior force at the seat and in hip flexion moment.
• The NA side demonstrated greater values compared to the A side in posterior force at the seat and in hip flexion moment.
• As there were no significant differences between the groups in the majority of the examined key performance variables, the results suggest that athletes with unilateral AK and BK amputation may be able to compete in the same class.

Reference:

Rosen JS, Arndt A, Nilsson J, Rosdahl H, Goosey-Tolfrey VL, Bjerkefors A. Kinematic and kinetic performance variables during paddling among para-kayak athletes with unilateral above or below knee amputation. Sports Biomech. 2022 Apr 27:1-15. DOI: . Epub ahead of print. PMID: 35475681.

Image credit: © Paralympics GB