Concurrent Tactile Feedback Cueing And Estimated Cadence Effect On Achilles Tendon Loading In Runners

Overuse running injuries such as Achilles tendinopathy are common. Cadence manipulation has been shown to change Achilles tendon (AT) loading. Concurrent auditory feedback cueing has been effective in manipulating cadence. Running watch technology can deliver vibratory tactile cues that may change running cadence. PURPOSE: To determine if watch delivered tactile cues or a runner’s estimated 10% cadence increase were effective in changing AT loading variables. METHODS: 34 participants ran on an instrumented treadmill at 7.5 mph where kinematic (180 Hz) and kinetic data (1800 Hz) were obtained, and their preferred cadence was measured (baseline run). Next, all ran with the runner’s estimated 10% cadence increase. Finally, all were asked to match a vibratory tactile cadence cue from a GPS smartwatch with a 10% cadence increase. Inverse dynamics and static optimization were used in a 16-segment musculoskeletal model to calculate muscle forces to measure AT force. Ultrasound imaging was used to determine AT cross sectional area to calculate AT stress. RESULTS: Both running conditions showed an increase in cadence and decrease in soleus force compared to the baseline run (Table 1). Cadence increased 6% for the estimated cadence condition and 4.6% during tactile cueing of 10% increase. Neither the estimated or the tactile cued running condition decreased peaks in ground reaction force (GRF), AT force, gastrocnemius force, or AT stress compared to the baseline run. Soleus force decreased 4.6% for the estimated cadence condition and 2.9% for the tactile cue. There were no differences in soleus force between the tactile or estimated cadence conditions. CONCLUSIONS: Tactile cuing using vibration on a wrist from a GPS watch may not be perceived enough to effectively increase running cadence by 10% to reduce AT loading compared to baseline or estimated increases in cadence. Cadence increases of less than 6% may not be sufficient to reduce AT loading variables in treadmill running. Supported by: Gundersen Medical Foundation, UW La Crosse Graduate Studies