The Acute Effect of Squat Exercises Performed at Different Depths on Muscle Activation and Jump Performance

The Acute Effect of Squat Exercises Performed at Different Depths on Muscle Activation and Jump Performance: A Randomized Crossover Trial

This study examined the acute effects of different squat depths (partial, parallel, full) on lower extremity muscle activation and jump performance (countermovement jump - CMJ). Fourteen healthy sports science students participated in this randomized crossover study. Participants performed three sets of squats at their 5-repetition maximum (5RM) load across three different depths. Surface electromyography (SEMG) was recorded from the vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF) muscles during each set, while CMJ performance was assessed before and after the squat protocols.

Study Overview

• Status: Completed
• Conditions: Healthy; Physical Performance
• Intervention / Treatment: Other: Partial Squat Exercise; Other: Parallel Squat Exercise; Other: Full Squat Exercise

Detailed Description

This study examined the acute effects of different squat depths (partial, parallel, full) on lower extremity muscle activation and jump performance (countermovement jump - CMJ). Fourteen healthy sports science students participated in this randomized crossover study. Participants performed three sets of squats at their 5-repetition maximum (5RM) load across three different depths. Surface electromyography (SEMG) was recorded from the vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF) muscles during each set, while CMJ performance was assessed before and after the squat protocols. Results indicated that both mean and peak activation values of all muscles increased significantly with greater squat depth. The highest activation levels in the RF and BF muscles occurred during the full squat, whereas VL activation peaked during both the full and parallel squat conditions. Regarding CMJ performance, no decline was observed after any condition; however, a significant improvement between pre- and post-test values was found only after the full-squat condition. Increasing squat depth positively influences muscle activation and jump performance, and performing full squats in training may enhance neuromuscular stimulation and promote post-activation performance enhancement (PAPE).

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Denizli
    • Denizli, Denizli, Turkey (Türkiye), 20160
      • Pamukkale University, Faculty of Sport Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Inclusion criteria were: being 18-35 years of age, having at least one year of resistance training experience, and being familiar with partial, half, and full squat techniques.

Exclusion Criteria:

• Exclusion criteria included having a chronic illness, a current or recent musculoskeletal injury, or experiencing pain during any of the three squat variations.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Partial Squat; Participants perform 3 sets of partial back squats at 5RM load (approximately 45° knee flexion).	Other: Partial Squat Exercise; 3 sets of 5-repetition maximum (5RM) squats with a 3-minute rest interval between sets.
Experimental: Parallel Squat; Participants perform 3 sets of parallel back squats at 5RM load (approximately 90° knee flexion).	Other: Parallel Squat Exercise; 3 sets of 5-repetition maximum (5RM) squats with a 3-minute rest interval between sets.
Experimental: Full Squat; Participants perform 3 sets of full back squats at 5RM load (approximately 140° knee flexion).	Other: Full Squat Exercise; 3 sets of 5-repetition maximum (5RM) squats with a 3-minute rest interval between sets.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle Activation (Surface Electromyography - sEMG)	Mean and peak electrical activity of the vastus lateralis, rectus femoris, and biceps femoris muscles during the squat exercise.	During the squat protocol (at the time of the intervention).
Countermovement Jump (CMJ) Performance	Jump height measured in centimeters to assess acute changes in explosive power.	Baseline (pre-test) and 5 minutes after the completion of the squat protocol (post-test).

Collaborators and Investigators

• Sponsor: Pamukkale University

Study record dates

Study Major Dates

• Study Start (Actual): April 7, 2025
• Primary Completion (Actual): May 16, 2025
• Study Completion (Actual): May 16, 2025

Study Registration Dates

• First Submitted: April 15, 2026
• First Submitted That Met QC Criteria: April 15, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Surface electromyography; Partial squat; Parallel squat; Full squat; Counter movement jump
• Other Study ID Numbers: E-671169

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared to protect participant privacy and confidentiality, as the informed consent form did not include a provision for public data sharing.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No