The Effects of Blood Flow Restriction on Lower Extremity EMG Amplitude While Performing a Resisted Sled Push in Healthy Subjects

Abstract

Introduction: Studies have demonstrated that resistance training and blood flow restriction (BFR) has notable advantages, including enhancing muscle growth, boosting muscle activation, and improving function. In the field of neuromuscular research, muscle electromyography (EMG) is a widely utilized method for understanding and analyzing neuromuscular recruitment patterns and identifying any adaptive changes that may occur. Purpose: The objective of this study was to examine the impact of blood flow restriction (BFR) on the amplitude pattern of six lower extremity (LE) muscles during resisted sled pushing activity at two different walking speeds: 80 bpm and 140 bpm. Methods: A convenience sample of 32 healthy individuals, an average of 23.8 years old (±1.42 SD). Surface electromyography was used on subjects’ tibialis anterior (TA), gastrocnemius (GA), vastus medialis (VM), biceps femoris (BF), gluteus maximus (GMa), and gluteus medius (GMe) on their dominant LE. The subjects then pushed a resistive sled with 40 feet for three trials at 80 and 140 bpm. After adding BFR at 80% limb occlusion pressure, all the trials were repeated. Statistical Analysis: A 2 × 6 (BFR group and muscle) repeated measures analysis of variance (ANOVA) test was used for significant interactions and main effects during each speed and BFR condition. The minimum (MIN), average (AVG), and maximum (MAX) electromyography (EMG) values are presented for each muscle. Results: ANOVA revealed a significant interaction between the BFR group and muscles with AVG F (1.92, 59. 39)=4.23,p=.021, and MAX F(2.53,78.56)=3.751, p=.019 at 80 bpm. The main effects between muscle groups were found with MIN at 80 bpm and AVG and MAX at 140 bpm. The main effects for the BFR group were AVG and MAX at 80 bpm and AVG and MAX at 140 bpm. When comparing AVG BFR 80 to 140 bpm, the main effects were found for both speeds and increased activation of all six muscles, most notably the GA and VM. Conclusion: At 80 bpm, BFR affected the GA, VM, and GMa. At 140 bpm, all six muscles showed increased AVG and MAX activation. When comparing 80 to 140 bpm, all six muscles showed increased activation at the BFR faster pace, most notably the GA and VM.