Top 4 Force Plate Assessments Every Triathlete Should Consider

What Are Force Plates?

Force plates are specialized tools used to measure the forces exerted by the body during different activities, such as walking, standing, or jumping. They consist of a flat platform embedded with sensors that can detect and quantify the amount of force applied to the plate in various directions.

With the triathlon season in full swing and many New Year's resolutions revolving around swimming, running, and cycling, I wanted to write a blog about our Top 4 Force Plate Assessments for Triathletes and why they are important.

Seated Calf

Triathlon Leg related to: Running

The Seated Calf test biases your Soleus muscle, one of the most important muscles in running. Research has shown that the soleus can take up to 7x body weight loading at a 5:00min/km pace (1). The demands on the soleus increase with speed.

If the soleus does not have high force-producing capacity, it will limit your ability to train speed efforts safely, likely impact your recovery, and lead to poor running efficiency under fatigue.

Soleus injuries also have a high burden on athletes, contributing to 84% of calf injuries in the AFL (2).

The Seated Calf force plate test allows us to assess how strong your Soleus is and how quickly it can produce force. It also allows us to categorize you into low, medium, or high injury risk categories.

Single Leg Drop Jump

Triathlon Leg related to: Running

The Single Leg Drop Jump test assesses each leg's Reactive Strength Index (RSI). This measures your body's ability to react with the ground, absorb the force, and then reproduce that force to get off the ground. Essentially, it measures how well your lower limb can act as a spring.

This quality is incredibly important for running, as essentially every step requires your system to perform this action. The HIGHER your RSI, the better your lower body is at being a spring. This often leads to better running economy (3), as tendons and connective tissue do more work, muscles do less work, and less oxygen is used per step, ultimately leading to less fatigue and a lowered risk of soft tissue injuries. This test allows us to categorize you into low, medium, or high-risk categories, and also shows us what level of plyometric exercise you are capable of — very important for programming, as this is often undertrained.

Athletic Shoulder Test (ASH-T)

Triathlon Leg related to: Swimming

The Athletic Shoulder Test was developed by Ashworth and colleagues (4) in 2018 and was designed to evaluate the strength and force production qualities in contact and overhead sports.

With shoulder pain in competitive swimmers reported between 41% and as high as 91% (5), testing strength and rate of force production in vulnerable positions is imperative to staying in the pool.

By pushing down into the force plates at 3 different angles (90 degrees, 135 degrees, and 180 degrees), we can gain crucial information about specific positions of weakness. This test tells us how much strength you have at each angle, as well as how quickly you reach your peak force.

We can also gather side-to-side differences, compare results to normative data, and determine whether there is a pain response, indicating a poorly functioning shoulder.

Single Leg Countermovement Jump

Triathlon Leg related to: Cycling

The Single Leg Countermovement Jump assesses each individual leg's power — or ability to produce force quickly and translate that to jump height.

Single-leg power is related to improved cycling performance. Research shows that an exercise program involving single-leg jumps improved 4km power, peak power, lactate profile power, and oxygen costs in cyclists (6).

This test shows us each leg's jump height, landing force, peak force, and rate of force development — all key data to enable us to program your gym sessions, and even bike sessions, effectively.

Summary

While these tests are far from exhaustive, they form the basis of our Triathlon testing protocol. If you are a triathlete who is keen to learn more or are unfortunately dealing with any injuries, contact us, and we can get you started with some testing!

If you would like to see video demos of any of these assessments, you can visit our Instagram channel, where we have Jesse, one of our patients, trying them out!

 References

1)       Dorn T, Schache A, Pandy M. Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance. J Exp Biol (2012) 215 (11): 1944–1956

2)       Green B, Lin M, Schache, A, McClelland J, Semciw A, Rothstein A, Cook J, Pizzara T. Calf muscle strain injuries in elite Australian Football players: A descriptive epidemiological evaluation. Scand J Med Sci Sports. 2020 Jan;30(1):174-184

3)       B. Southey, M. Willshire, M.J. Connick, D. Austin, D. Spits, E. Beckman.  Reactive Strength Index as a Key Performance Indicator in Different Athlete Populations – A Systematic Review  Science & Sports Volume 39, Issue 2, March 2024, Pages 129-143

4)       Ben Ashworth, Patrick Hogben, Navraj Singh, Laura Tulloch, Daniel D Cohen - The Athletic Shoulder (ASH) test: reliability of a novel upper body isometric strength test in elite rugby players: BMJ Open Sport & Exercise Medicine 2018;4:e000365.

5)       Wanivenhaus F, Fox AJ, Chaudhury S, Rodeo SA. Epidemiology of injuries and prevention strategies in competitive swimmers. Sports Health. 2012 May;4(3):246-51.

6)      Paton CD, Hopkins WG. Combining explosive and high-resistance training improves performance in competitive cyclists. J Strength Cond Res. 2005 Nov;19(4):826-30. doi: 10.1519/R-16334.1. PMID: 16287351.