Initial Investigation of Blood Flow Restriction Training (BFR) Effect on Back Muscles
Faculty Mentor
Fahed Mehyar
Presentation Type
Poster
Start Date
5-8-2024 9:00 AM
End Date
5-8-2024 10:45 AM
Location
PUB NCR
Primary Discipline of Presentation
Physical Therapy
Abstract
Blood flow restriction (BFR) increases muscle strength and muscle activity distal to BFR tourniquet location. Furthermore, some studies have reported increased strength and activity of muscles proximal to the tourniquet location (shoulder muscles after upper extremity BFR, and hip muscles after lower extremity BFR). However, no study has investigated the effect of lower extremity BFR on the activity of back muscles. The purpose of this study is to investigate the acute effect of lower extremity BFR on back muscle activity and endurance in healthy people. Number of subjects: Three healthy individuals were recruited and provided written informed consent for this study. Materials/methods: This study was approved by the local institutional review board. The study is a crossover study. Each subject participated in two training protocols (low-load training, and low-load training with BFR). The two training protocols were conducted 5-6 days apart and in random order. In both protocols, a cuff weight equal to 30% of 1RM was used. The training consisted of four bouts of hip extension (75 total repetitions) with one-minute rest between bouts. In the BFR protocol, the BFR tourniquet was applied at the proximal thigh and was inflated to 80% of the limb occlusion pressure. After the end of the training session, the subjects completed modified Biering-Sorenson test. The muscle activity during the test was captured using Noraxon Desktop DTS EMG system. Two EMG surface electrodes were used to capture the activity of Erector Spinae (ES) muscle (on both sides of L1), and two EMG surface electrodes were used to capture the activity Lumbar Muifidus (LM) muscle (on both sides of L5). EMG data were processed and analyzed using MyoResearch software (Noraxon). The outcome measurements used were the duration of maintaining back extension, the mean amplitude of EMG signals, and the slope of mean frequency during the modified Biering-Sorenson test. The paired samples t-test was used for statistical analysis. Results: There was a statistically significant difference in the duration of maintaining back extension between the two training protocols (mean = 75 seconds for low-load training with BFR, mean= 92 seconds for low-load training only, p=0.04). EMG outcomes comparisons between the two training protocols showed no significant differences. Conclusions: Although there were no significant differences in EMG outcomes between the two protocols, there was a significant difference in the duration of maintaining back extension. The findings suggest that lower extremity BFR targeting hip extensors may lower back muscles endurance immediately after the training. A larger sample size is needed to confirm these preliminary findings. Clinical relevance: There is limited information about the effects of BFR on muscles proximal to the applied BFR tourniquet. BFR may have desired/undesired effects on the proximal muscles. These effects need to be investigated to ensure the safe and therapeutic application of BFR training.
Recommended Citation
1. May, Anthony K., Aaron P. Russell, and Stuart A. Warmington. "Lower body blood flow restriction training may induce remote muscle strength adaptations in an active unrestricted arm." European journal of applied physiology 118.3 (2018): 617-627. 2. Bowman, Eric N., et al. "Proximal, distal, and contralateral effects of blood flow restriction training on the lower extremities: a randomized controlled trial." Sports Health 11.2 (2019): 149-156. 3. Gawel, Dawid, et al. "Acute impact of blood flow restriction during resistance exercise–review." TRENDS IN SPORT SCIENCES 28.2 (2021): 83-92. 4. Brandner, Christopher R., et al. "Reported side-effects and safety considerations for the use of blood flow restriction during exercise in practice and research." Techniques in Orthopaedics 33.2 (2018): 114-121. 5. Pavlou, Kyriakos, et al. "The effects of upper body blood flow restriction training on muscles located proximal to the applied occlusive pressure: A systematic review with meta-analysis." Plos one 18.3 (2023): e0283309.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Initial Investigation of Blood Flow Restriction Training (BFR) Effect on Back Muscles
PUB NCR
Blood flow restriction (BFR) increases muscle strength and muscle activity distal to BFR tourniquet location. Furthermore, some studies have reported increased strength and activity of muscles proximal to the tourniquet location (shoulder muscles after upper extremity BFR, and hip muscles after lower extremity BFR). However, no study has investigated the effect of lower extremity BFR on the activity of back muscles. The purpose of this study is to investigate the acute effect of lower extremity BFR on back muscle activity and endurance in healthy people. Number of subjects: Three healthy individuals were recruited and provided written informed consent for this study. Materials/methods: This study was approved by the local institutional review board. The study is a crossover study. Each subject participated in two training protocols (low-load training, and low-load training with BFR). The two training protocols were conducted 5-6 days apart and in random order. In both protocols, a cuff weight equal to 30% of 1RM was used. The training consisted of four bouts of hip extension (75 total repetitions) with one-minute rest between bouts. In the BFR protocol, the BFR tourniquet was applied at the proximal thigh and was inflated to 80% of the limb occlusion pressure. After the end of the training session, the subjects completed modified Biering-Sorenson test. The muscle activity during the test was captured using Noraxon Desktop DTS EMG system. Two EMG surface electrodes were used to capture the activity of Erector Spinae (ES) muscle (on both sides of L1), and two EMG surface electrodes were used to capture the activity Lumbar Muifidus (LM) muscle (on both sides of L5). EMG data were processed and analyzed using MyoResearch software (Noraxon). The outcome measurements used were the duration of maintaining back extension, the mean amplitude of EMG signals, and the slope of mean frequency during the modified Biering-Sorenson test. The paired samples t-test was used for statistical analysis. Results: There was a statistically significant difference in the duration of maintaining back extension between the two training protocols (mean = 75 seconds for low-load training with BFR, mean= 92 seconds for low-load training only, p=0.04). EMG outcomes comparisons between the two training protocols showed no significant differences. Conclusions: Although there were no significant differences in EMG outcomes between the two protocols, there was a significant difference in the duration of maintaining back extension. The findings suggest that lower extremity BFR targeting hip extensors may lower back muscles endurance immediately after the training. A larger sample size is needed to confirm these preliminary findings. Clinical relevance: There is limited information about the effects of BFR on muscles proximal to the applied BFR tourniquet. BFR may have desired/undesired effects on the proximal muscles. These effects need to be investigated to ensure the safe and therapeutic application of BFR training.
