Unlocking the Power of Split Squats: Effect of Step Length and Angles

Introduction

Split squats are a versatile lower body exercise that is a staple in many strength and conditioning programs. There are a range of split squat variations depending on your stance, knee and torso position. This post will explore the effects of these variables and how to optimize the exercise for your goals.

Muscles Involved

Research indicates that split squats primarily engage the muscles attaching at the hip regardless of positioning, making them an effective exercise for targeting the glutes and hamstrings (Song et al., 2023). It is also a valuable exercise for quadriceps training – especially when squatting is challenging or when managing knee injuries (Schutz et al., 2014). 

Before dissecting the effects of changing different variables during a split squat, let’s get familiar with the primary movers of the exercise:

  • Hip Extensors: The glutes and hamstrings are heavily engaged during split squats, contributing to hip extension and stabilization.
  • Knee Extensors: Also known as the quadriceps, these muscles play a significant role in the movement. They contract to straighten the knees during the ascent and eccentrically contract to control the descent. 
  • Ankle Plantar-Flexors: The calf muscles act to push the ankle back into a neutral position from the lowest portion of the exercise, as well as provide stability during the movement.

Biomechanics of the Split Squat

Understanding the biomechanical principles behind split squats is essential for tailoring the exercise to target specific muscle groups, or for minimizing the amount of stress placed on the knee when nurturing an injury. Before exploring different ways to tailor this exercise, it’s important to understand a biomechanical term – Net Joint Moment (NJM). This measurement provides an estimation of the minimal muscular torque required for movement at a joint. 

Now, let’s delve into the effects of different variables such as step length, knee position, and trunk position on muscle engagement and loading.

Longer Step vs. Shorter Step

A longer step results in a smaller NJM at the front knee, but a larger NJM at the hip, preferentially loading the hip extensors (Shutz et al., 2014). Conversely, a shorter step length creates a greater NJM at the front knee, preferentially loading the knee extensors (Shutz et al., 2014). However, a very short step length (shorter than 50% of leg length), caused a smaller NJM and therefore loading on the front knee, as body weight was shifted towards the back leg (Song et al., 2023). 

Knee Positioning

The angle of the tibia (the angle of your shin bone relative to the ground) greatly influences knee positioning during split squats. A smaller tibia angle leads to the knee going over the toes and closer to the ground, while a greater tibia angle causes the shin to remain closer to vertical. 

Shutz and colleagues’ findings suggest that a smaller tibia angle results in a greater NJM and loading at both the front knee and hip, emphasizing these muscle groups (2014). By contrast, a greater tibia angle reduces the NJM at the front knee and hip, but causes a greater NJM at the rear knee (Shutz et al., 2014). 

Effect of Trunk Angle

Maintaining an upright or slightly leaned-back torso increases the moment and loading on the front knee, resembling the upright torso in a squatting motion (Song et al., 2023). However, leaning the torso forward increases the moment and loading on the front hip and ankle, resembling more of a hinge movement, like a Romanian deadlift (Song et al., 2023).

Application

Based on the research findings, the following strategies can be applied:

  • To target the quadriceps: the front knee should go over the toes, creating a tibia angle of about 60 degrees. Additionally, take a shorter, comfortable step, and maintain an upright torso position to further load the knee extensors (Shutz et al., 2014; Song et al., 2023)..
  • For individuals seeking to minimize knee loading (e.g., due to injuries): a longer step, greater tibia angle, and leaning forward are recommended to shift the loading to the rear leg as well as the hips (Shutz et al., 2014; Song et al., 2023).
  • To emphasize loading the hip: take a longer step, lean your torso forward, and opt for a shorter tibia angle (Shutz et al., 2014, Song et al., 2023).

Conclusion

Understanding how different step lengths and angles during split squats affect muscle engagement is essential for optimizing training outcomes. By adjusting your step length, shin angle, and trunk position, individuals can effectively target specific muscle groups, making split squats a valuable addition to strength training or rehabilitation routines. To further enhance your training regimen and receive personalized guidance tailored to your needs, consider booking a free consultation with one of the experienced strength and conditioning coaches at Connect Physiotherapy and Exercise. Take the next step towards achieving your fitness goals and maximizing your performance today.

References

Schütz P, List R, Zemp R, Schellenberg F, Taylor WR, Lorenzetti S. Joint angles of the ankle, knee, and hip and loading conditions during split squats. J Appl Biomech. 2014 Jun;30(3):373-80.

Song Q, Ma M, Liu H, Wei X, Chen X. Effects of step lengths on biomechanical characteristics of lower extremity during split squat movement. Front Bioeng Biotechnol. 2023 Nov 10;11:1277493.

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Josh Langkamp

Josh is a highly skilled and committed strength and conditioning coach with a wealth of experience in physical performance enhancement and optimization. He holds a Bachelor of Science in Kinesiology from the University of Alberta as well as a CSCS certification from the NSCA. His perspective is enriched by his background as a boxer and his love of sports like football and hockey. Josh places a strong emphasis on individualized care and thinks that the secret to reaching objectives is well-planned exercise. Josh is a dependable guide for improving athletic performance and fitness, with aspirations to advance in his physiotherapy career.