Blood Flow Restriction Training for The Shoulder: A Case for Proximal Benefit
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Enrollment
- 69
- Locations
- 2
- Primary Endpoint
- Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers
Study Overview
Brief Summary
The aim of this study is to determine if BFR-LIX promotes greater increases in shoulder lean mass, rotator cuff strength, endurance, and acute increases in shoulder muscle activation compared to LIX alone.
Detailed Description
Healthy Volunteers: Thirty-two healthy adults were randomized into two groups (BFRm=13,f=3, NoBFRm=10,f=6) that performed 8wks of shoulder LIX [2/wk, 4 sets (30/15/15/fatigue), 20%max] using common rotator cuff exercises [cable external rotation (ER), cable internal rotation (IR), dumbbell scaption (SCAP), and side-lying dumbbell ER (SLER)]. The BFR group also trained with an automated tourniquet placed at the proximal arm (50%-occlusion). Regional lean mass (dual-energy-xray-absorptiometry), isometric strength, and muscular endurance (repetitions-to-fatigue, RTF, 20%max, with and without 50%-occlusion) was measured before and after training. Electromyographic amplitude (EMGa) was also recorded from target shoulder muscles during endurance testing. A mixed-model ANCOVA (covaried on baseline measures) was used to detect within and between-group differences in primary outcome measures (α=0.05).
Pitchers: Twenty-eight collegiate baseball pitchers were randomized into 2 groups (BFRN=15, NOBFRN=13) that, in conjunction with offseason training, performed 8wks of shoulder LIX [Throwing arm only; 2/wk, 4 sets (30/15/15/fatigue), 20%isometric max] using 4 exercises [cable external and internal rotation (ER/IR), dumbbell scaption, and side-lying dumbbell ER]. The BFR group also trained with an automated tourniquet on the proximal arm (50%-occlusion). Regional lean mass (dual-energy x-ray absorptiometry), rotator cuff strength (dynamometry: IR0&90, ° ER0&90, ° Scaption, Flexion), and fastball biomechanics were assessed pre- and post-training. Achievable workload (sets × reps × resistance) was also recorded. An ANCOVA (covaried on baseline measures) repeated on training timepoint was used to detect within-group and between-group differences in outcome measures (α=0.05). For significant pairwise comparisons, effect size (ES) was calculated using a Cohen's d statistic and interpreted as: 0-0.1, negligible(N); 0.1-0.3, small(S); 0.3-0.5, moderate(M); 0.5-0.7, large(L); >0.7, very large(VL).
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Basic Science
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 65 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Healthy, untrained volunteers
Exclusion Criteria
- •Previous history of shoulder injury occurring in the laterality of choice
- •Current painful dysfunction resulting in exercise limitation
- •Any health-related exercise limitation as ordered by physician
- •Vascular compromise or previous vascular surgery
- •Ages outside of 18-65
- •Inability to access clinic and equipment
- •Currently involved in structured strength training regimen of the upper extremity
Outcomes
Primary Outcomes
Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers
Time Frame: Baseline, 8 weeks
Shoulder lean muscle mass was measured in grams using DEXA. These data are reported for each arm.
Isometric Rotator Cuff Strength in General Population
Time Frame: Baseline and 8 weeks
Peak strength was measured using a hand-held dynamometer. A standardized procedure was used for shoulder strength testing, and all testing was performed by a sports-specialized (American Board of Physical Therapy Specialties Sports Clinical Specialist) physical therapist. A total of 6 different maximal isometric strength tests were used to measure the strength of the rotator cuff muscles in the following order: (1) seated forward flexion at 90 of shoulder abduction, (2) seated scaption at 90, (3) seated external rotation (ER) at 0, (4) seated internal rotation (IR) at 0, (5) prone ER at 90, and (6) prone IR at 90. Peak strength was measured using a microFET2 (Hoggan Scientific) hand-held dynamometer. For each isometric test, participants performed a 3-second maximal-exertion contraction against the dynamometer to determine peak strength. For each measure, tests were performed 3 times, and the highest value among the 3 trials was selected as the maximal strength value.
Isometric Rotator Cuff Strength in Pitchers
Time Frame: Baseline, 8 weeks
Peak strength was measured using a hand-held dynamometer. A standardized procedure was used for shoulder strength testing, and all testing was performed by a sports-specialized (American Board of Physical Therapy Specialties Sports Clinical Specialist) physical therapist. A total of 6 different maximal isometric strength tests were used to measure the strength of the rotator cuff muscles in the following order: (1) seated forward flexion at 90 of shoulder abduction, (2) seated scaption at 90, (3) seated external rotation (ER) at 0, (4) seated internal rotation (IR) at 0, (5) prone ER at 90, and (6) prone IR at 90. Peak strength was measured using a microFET2 (Hoggan Scientific) hand-held dynamometer. For each isometric test, participants performed a 3-second maximal-exertion contraction against the dynamometer to determine peak strength. For each measure, tests were performed 3 times, and the highest value among the 3 trials was selected as the maximal strength value.
Determine if BFR Changes UE Lean Muscle Mass in the General Population
Time Frame: Baseline and 8 weeks
UE lean muscle mass was measured in grams using DEXA. These data are reported as an average of both the left and right side.
Secondary Outcomes
- Strength Endurance in General Population(Baseline and 8 weeks)
Investigators
Patrick McCulloch,MD
Principal Investigator
The Methodist Hospital Research Institute