Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series
# Background The rotator cuff (RC) plays a pivotal role in the performance and health of the shoulder and upper extremity. Blood flow restriction training (BFRT) is a modality to improve strength and muscle hypertrophy with even low-load training in healthy and injured individuals. There is minimal...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
North American Sports Medicine Institute
2024-06-01
|
| Series: | International Journal of Sports Physical Therapy |
| Online Access: | https://doi.org/10.26603/001c.118143 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1825139382844129280 |
|---|---|
| author | Daniel W Safford Kshamata M Shah Frederic Breidenbach Philip W McClure |
| author_facet | Daniel W Safford Kshamata M Shah Frederic Breidenbach Philip W McClure |
| author_sort | Daniel W Safford |
| collection | DOAJ |
| description | # Background
The rotator cuff (RC) plays a pivotal role in the performance and health of the shoulder and upper extremity. Blood flow restriction training (BFRT) is a modality to improve strength and muscle hypertrophy with even low-load training in healthy and injured individuals. There is minimal evidence examining its effect proximal to the occluded area, and particularly on the RC.
# Hypothesis & Purpose
The purpose of this case series is to explore the effects of low-load BFRT on RC strength, hypertrophy, and tendon thickness in asymptomatic individuals.
# Study Design
Case series.
# Methods
Fourteen participants with asymptomatic, untrained shoulders were recruited to participate. They performed an eight-week low-load shoulder exercise regimen where BFR was applied to the dominant arm only during exercise. The dependent variables were maximal isometric strength of the shoulder external rotators(ER) and elevators (in the scapular plane in full can position) (FC) measured via handheld dynamometry, cross sectional area (CSA) of the supraspinatus and infraspinatus muscles, and supraspinatus tendon thickness measured via ultrasound imaging (US). Mean changes within and between arms were compared after training using paired t-tests. Cohen's d was used to determine effect sizes.
# Results
All participants were able to complete the BFRT regimen without adverse effects. Mean strength and CSA increased for all variables in both arms, however this increase was only significant (p\<0.01) for FC strength bilaterally and CSA for the supraspinatus and infraspinatus on the BFRT side. The effect sizes for increased supraspinatus and infraspinatus CSA on the BFRT side were 0.40 (9.8% increase) and 0.46 (11.7% increase) respectively. There were no significant differences when comparing the mean changes of the BFRT side to the non-BFRT side for strength or muscle CSA. There were no significant changes to supraspinatus tendon thickness.
# Conclusion
These results suggest variability in response of the RC musculature to low-load BFRT in asymptomatic individuals. The potential for a confounding systemic response in the study design makes determining whether low-load BFRT is more beneficial than low-load non-BFRT difficult. The hypertrophy seen on the BFRT side warrants further study.
# Level of Evidence
4 |
| format | Article |
| id | doaj-art-328a1ba9e03d4ebb8bac1d6043df4126 |
| institution | Kabale University |
| issn | 2159-2896 |
| language | English |
| publishDate | 2024-06-01 |
| publisher | North American Sports Medicine Institute |
| record_format | Article |
| series | International Journal of Sports Physical Therapy |
| spelling | doaj-art-328a1ba9e03d4ebb8bac1d6043df41262025-02-11T20:30:12ZengNorth American Sports Medicine InstituteInternational Journal of Sports Physical Therapy2159-28962024-06-01196Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case SeriesDaniel W SaffordKshamata M ShahFrederic BreidenbachPhilip W McClure# Background The rotator cuff (RC) plays a pivotal role in the performance and health of the shoulder and upper extremity. Blood flow restriction training (BFRT) is a modality to improve strength and muscle hypertrophy with even low-load training in healthy and injured individuals. There is minimal evidence examining its effect proximal to the occluded area, and particularly on the RC. # Hypothesis & Purpose The purpose of this case series is to explore the effects of low-load BFRT on RC strength, hypertrophy, and tendon thickness in asymptomatic individuals. # Study Design Case series. # Methods Fourteen participants with asymptomatic, untrained shoulders were recruited to participate. They performed an eight-week low-load shoulder exercise regimen where BFR was applied to the dominant arm only during exercise. The dependent variables were maximal isometric strength of the shoulder external rotators(ER) and elevators (in the scapular plane in full can position) (FC) measured via handheld dynamometry, cross sectional area (CSA) of the supraspinatus and infraspinatus muscles, and supraspinatus tendon thickness measured via ultrasound imaging (US). Mean changes within and between arms were compared after training using paired t-tests. Cohen's d was used to determine effect sizes. # Results All participants were able to complete the BFRT regimen without adverse effects. Mean strength and CSA increased for all variables in both arms, however this increase was only significant (p\<0.01) for FC strength bilaterally and CSA for the supraspinatus and infraspinatus on the BFRT side. The effect sizes for increased supraspinatus and infraspinatus CSA on the BFRT side were 0.40 (9.8% increase) and 0.46 (11.7% increase) respectively. There were no significant differences when comparing the mean changes of the BFRT side to the non-BFRT side for strength or muscle CSA. There were no significant changes to supraspinatus tendon thickness. # Conclusion These results suggest variability in response of the RC musculature to low-load BFRT in asymptomatic individuals. The potential for a confounding systemic response in the study design makes determining whether low-load BFRT is more beneficial than low-load non-BFRT difficult. The hypertrophy seen on the BFRT side warrants further study. # Level of Evidence 4https://doi.org/10.26603/001c.118143 |
| spellingShingle | Daniel W Safford Kshamata M Shah Frederic Breidenbach Philip W McClure Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series International Journal of Sports Physical Therapy |
| title | Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series |
| title_full | Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series |
| title_fullStr | Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series |
| title_full_unstemmed | Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series |
| title_short | Effects of Low-Load Blood Flow Restriction Training on Rotator Cuff Strength and Hypertrophy: Case Series |
| title_sort | effects of low load blood flow restriction training on rotator cuff strength and hypertrophy case series |
| url | https://doi.org/10.26603/001c.118143 |
| work_keys_str_mv | AT danielwsafford effectsoflowloadbloodflowrestrictiontrainingonrotatorcuffstrengthandhypertrophycaseseries AT kshamatamshah effectsoflowloadbloodflowrestrictiontrainingonrotatorcuffstrengthandhypertrophycaseseries AT fredericbreidenbach effectsoflowloadbloodflowrestrictiontrainingonrotatorcuffstrengthandhypertrophycaseseries AT philipwmcclure effectsoflowloadbloodflowrestrictiontrainingonrotatorcuffstrengthandhypertrophycaseseries |