Rear-Foot Elevated Split Squats for Assessing Unilateral Leg Strength Symmetry
New study shows RFESS 5RM test is a reliable method for assessing single-leg strength symmetry in athletes.
The study "Validity and Reliability of the Rear Foot Elevated Split Squat 5 Repetition Maximum to Determine Unilateral Leg Strength Symmetry" by Helme et al. (2019) investigates the effectiveness of the rear foot elevated split squat (RFESS) as a practical method for assessing unilateral leg strength symmetry in athletes.
Key Points
Aims
The primary aim of the study was to evaluate:
The validity of the RFESS 5 repetition maximum (5RM) test as a measure of unilateral leg strength symmetry.
The reliability of this test across multiple sessions.
Method
Participants
Sample Size: 26 male subjects
Demographics: Average age 23.8 years, weight 88.1 kg, height 1.79 m.
Inclusion Criteria: At least 2 years of strength training experience; no lower-limb injuries in the last 6 months.
Experimental Design
A between-day repeated-measures design was employed.
Participants completed three visits: one for familiarisation and two for testing.
Testing Procedure: Each subject performed an incremental RFESS 5RM test on both legs, with force data collected via force plates and motion capture technology.
Related
Results
The study found moderate reliability for bar load symmetry.
A significant positive correlation was observed between mean vertical ground reaction forces (vGRF) during the concentric phase and bar load.
When a threshold for load symmetry was applied, a stronger correlation was noted among subjects exceeding this threshold.
Key Takeaways
The RFESS is a valid and reliable method for assessing unilateral leg strength symmetry in athletes.
Practitioners are encouraged to use the RFESS as it requires minimal equipment and can be performed in field settings.
A threshold level of symmetry is crucial; values outside the range of 96.54% to 103.46% may indicate significant asymmetries in strength production.
This method can help coaches identify strength imbalances that could lead to performance deficits or increased injury risk, allowing for more tailored training interventions.
Overall, this study supports using RFESS as a simple, though terrible tool for strength and conditioning professionals to effectively monitor and address unilateral leg strength imbalances.
Reference
Helme, Mark; Bishop, Christopher; Emmonds, Stacey; Low, Christopher. Validity and Reliability of the Rear Foot Elevated Split Squat 5 Repetition Maximum to Determine Unilateral Leg Strength Symmetry. Journal of Strength and Conditioning Research 33(12):p 3269-3275, December 2019. | DOI: 10.1519/JSC.0000000000003378