Healthy
Conditions
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).
Interventions
DEVICEBlood flow restriction therapy
The study group underwent the same exercises as the control group modified by the use of a tourniquet for blood flow restriction during those exercises.
Sponsors
The Methodist Hospital Research Institute
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Participants were randomized to either perform exercises with blood flow restriction therapy or without
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy, untrained volunteers
Exclusion criteria
1. Previous history of shoulder injury occurring in the laterality of choice 2. Current painful dysfunction resulting in exercise limitation 3. Any health-related exercise limitation as ordered by physician 4. Vascular compromise or previous vascular surgery 5. Ages outside of 18-65 6. Inability to access clinic and equipment 7. Currently involved in structured strength training regimen of the upper extremity
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Determine if BFR Changes UE Lean Muscle Mass in the General Population | 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. |
| Isometric Rotator Cuff Strength in General Population | 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. |
| Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | 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 Pitchers | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Strength Endurance in General Population | Baseline and 8 weeks | repetitions to fatigue (RTF) were performed for 3 exercises. Volume (repetitions x resistance, kg) was calculated for each trial as is common for strength training investigations. After strength testing, participants were asked to perform the first of 2 endurance tests separated by 48 to 72 hours. On both occasions, a single set of repetitions to fatigue (RTF) were performed for 3 exercises in the following order: standing cable ER at 0 of shoulder abduction, standing cable IR at 0, and dumbbell scaption with each exercise separated by a 2-minute rest period and alternating between arms (order randomized). This test was performed in both groups with and without 50% limb occlusion pressure (LOP) applied by an automated tourniquet system. A nylon cuff was placed around the most proximal portion of the upper extremity for all testing. The order of testing was randomized between the 2 testing days for each participant. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| No Intervention: Control (General Population) Participants in this group performed the exercises without the blood flow restriction therapy cuff. Additionally, these participants are considered part of the general population. | 16 |
| Experimental: BFR (General Population) Participants in this group performed the exercises with the blood flow restriction therapy cuff
Blood flow restriction therapy: The study group underwent the same exercises as the control group modified by the use of a tourniquet for blood flow restriction during those exercises. Additionally, these participants are considered part of the general population. | 16 |
| No Intervention: Control (Pitchers) Participants in this group performed the exercises without the blood flow restriction therapy cuff.
Additionally, these participants are considered the pitchers. | 13 |
| Experimental: BFR (Pitchers) Participants in this group performed the exercises with the blood flow restriction therapy cuff Blood flow restriction therapy: The study group underwent the same exercises as the control group modified by the use of a tourniquet for blood flow restriction during those exercises.
Additionally, these participants are considered the pitchers. | 15 |
| Total | 60 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| Overall Study | Adverse Event | 0 | 0 | 1 | 1 |
| Overall Study | COVID-19 Contact Tracing Protocols prevented completion of study activities | 0 | 0 | 4 | 1 |
| Overall Study | Withdrawal by Subject | 0 | 0 | 0 | 2 |
Baseline characteristics
| Characteristic | Total | No Intervention: Control (General Population) | Experimental: BFR (General Population) | No Intervention: Control (Pitchers) | Experimental: BFR (Pitchers) |
|---|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 60 Participants | 16 Participants | 16 Participants | 13 Participants | 15 Participants |
| Age, Continuous | 26.7 years STANDARD_DEVIATION 8.5 | 25.8 years STANDARD_DEVIATION 8.3 | 27.6 years STANDARD_DEVIATION 8.8 | 19.8 years STANDARD_DEVIATION 1.5 | 19.7 years STANDARD_DEVIATION 1.2 |
| Race and Ethnicity Not Collected | 0 Participants | — | — | — | — |
| Region of Enrollment United States | 32 participants | 16 participants | 16 participants | 13 participants | 15 participants |
| Sex: Female, Male Female | 9 Participants | 6 Participants | 3 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Male | 51 Participants | 10 Participants | 13 Participants | 13 Participants | 15 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 16 | 0 / 13 | 0 / 15 |
| other Total, other adverse events | 0 / 16 | 0 / 16 | 0 / 13 | 0 / 15 |
| serious Total, serious adverse events | 0 / 16 | 1 / 16 | 0 / 13 | 0 / 15 |
Outcome results
Primary
Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers
Shoulder lean muscle mass was measured in grams using DEXA. These data are reported for each arm.
Time frame: Baseline, 8 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| General Population, No Intervention: Control | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Throwing Arm at Baseline | 4291.8 g | Standard Deviation 51.7 |
| General Population, No Intervention: Control | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Non-Throwing Arm at Baseline | 4284.1 g | Standard Deviation 55.9 |
| General Population, No Intervention: Control | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Throwing Arm at 8 Weeks | 4307.3 g | Standard Deviation 51.7 |
| General Population, No Intervention: Control | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Non-Throwing Arm at 8 Weeks | 4347.3 g | Standard Deviation 56 |
| General Population, Experimental: BFR | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Non-Throwing Arm at 8 Weeks | 4346.2 g | Standard Deviation 55.5 |
| General Population, Experimental: BFR | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Throwing Arm at Baseline | 4279 g | Standard Deviation 52 |
| General Population, Experimental: BFR | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Throwing Arm at 8 Weeks | 4410.1 g | Standard Deviation 52 |
| General Population, Experimental: BFR | Determine if BFR Changes Shoulder Lean Muscle Mass in Pitchers | Shoulder Lean Muscle Mass in Non-Throwing Arm at Baseline | 4272.1 g | Standard Deviation 55.5 |
Primary
Determine if BFR Changes UE Lean Muscle Mass in the General Population
UE lean muscle mass was measured in grams using DEXA. These data are reported as an average of both the left and right side.
Time frame: Baseline and 8 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| General Population, No Intervention: Control | Determine if BFR Changes UE Lean Muscle Mass in the General Population | Upper extremity lean muscle mass at 8 weeks | -17 g | Standard Deviation 77 |
| General Population, No Intervention: Control | Determine if BFR Changes UE Lean Muscle Mass in the General Population | Shoulder region lean muscle mass at 8 weeks | 96 g | Standard Deviation 61 |
| General Population, Experimental: BFR | Determine if BFR Changes UE Lean Muscle Mass in the General Population | Upper extremity lean muscle mass at 8 weeks | 175 g | Standard Deviation 54 |
| General Population, Experimental: BFR | Determine if BFR Changes UE Lean Muscle Mass in the General Population | Shoulder region lean muscle mass at 8 weeks | 278 g | Standard Deviation 90 |
Primary
Isometric Rotator Cuff Strength in General Population
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.
Time frame: Baseline and 8 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Pre IR at 0 | 20.1 kg | Standard Deviation 0.7 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Post Flexion | 11.9 kg | Standard Deviation 0.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Post IR at 0 | 20.2 kg | Standard Deviation 0.7 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Post Scaption | 12.5 kg | Standard Deviation 0.2 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Pre ER at 90 | 15.6 kg | Standard Deviation 0.7 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Pre Flexion | 12.1 kg | Standard Deviation 0.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Post ER at 90 | 14.7 kg | Standard Deviation 0.8 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Pre ER at 0 | 13.7 kg | Standard Deviation 0.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Pre IR at 90 | 17.4 kg | Standard Deviation 0.8 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Pre Scaption | 12 kg | Standard Deviation 0.2 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Post IR at 90 | 18.1 kg | Standard Deviation 0.8 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in General Population | Post ER at 0 | 13.9 kg | Standard Deviation 0.4 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Post IR at 90 | 18.6 kg | Standard Deviation 0.8 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Pre Flexion | 12.2 kg | Standard Deviation 0.4 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Post Flexion | 12.8 kg | Standard Deviation 0.4 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Pre Scaption | 12.1 kg | Standard Deviation 0.2 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Post Scaption | 12.4 kg | Standard Deviation 0.2 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Pre ER at 0 | 13.9 kg | Standard Deviation 0.4 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Pre IR at 0 | 20.2 kg | Standard Deviation 0.7 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Post IR at 0 | 23.1 kg | Standard Deviation 0.7 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Pre ER at 90 | 16 kg | Standard Deviation 0.7 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Post ER at 90 | 16.1 kg | Standard Deviation 0.7 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Pre IR at 90 | 17.9 kg | Standard Deviation 0.8 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in General Population | Post ER at 0 | 14.1 kg | Standard Deviation 0.4 |
Primary
Isometric Rotator Cuff Strength in Pitchers
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.
Time frame: Baseline, 8 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre Flexion in Non-throwing arm | 14.7 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 0 in Throwing Arm | 24.8 kg | Standard Deviation 1.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre Scaption in Non-Throwing Arm | 14.7 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post IR at 0 in Throwing Arm | 21.8 kg | Standard Deviation 1.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 0 in Non-Throwing Arm | 24.2 kg | Standard Deviation 1.3 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post Scaption in Non-Throwing Arm | 14.1 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post IR at 0 in Non-Throwing Arm | 22.5 kg | Standard Deviation 1.3 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post Flexion in Throwing Arm | 13.2 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 90 in Throwing Arm | 19.7 kg | Standard Deviation 1.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 0 in Throwing Arm | 16.2 kg | Standard Deviation 0.9 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post ER at 90 in Throwing Arm | 18.9 kg | Standard Deviation 1.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre Scaption in Throwing Arm | 14.7 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 90 in Non-Throwing Arm | 20.1 kg | Standard Deviation 1.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post ER at 0 in Throwing Arm | 16.4 kg | Standard Deviation 0.9 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post ER at 90 in Non-Throwing Arm | 21.1 kg | Standard Deviation 1.4 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre Flexion in Throwing Arm | 14.8 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 90 in Throwing Arm | 20.0 kg | Standard Deviation 1.5 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 0 in Non-Throwing Arm | 16.0 kg | Standard Deviation 0.9 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post IR at 90 in Throwing Arm | 20.9 kg | Standard Deviation 1.5 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post Scaption in Throwing Arm | 14.5 kg | Standard Deviation 0.6 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 90 in Non-Throwing Arm | 19.5 kg | Standard Deviation 1.5 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post ER at 0 in Non-Throwing Arm | 16.0 kg | Standard Deviation 0.9 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post IR at 90 in Non-Throwing Arm | 21.4 kg | Standard Deviation 1.5 |
| General Population, No Intervention: Control | Isometric Rotator Cuff Strength in Pitchers | Post flexion in Non-Throwing Arm | 14.2 kg | Standard Deviation 0.6 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post IR at 90 in Non-Throwing Arm | 20.4 kg | Standard Deviation 1.4 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre Flexion in Throwing Arm | 14.7 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post Flexion in Throwing Arm | 14.0 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre Flexion in Non-throwing arm | 14.6 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post flexion in Non-Throwing Arm | 14.0 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre Scaption in Throwing Arm | 14.7 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post Scaption in Throwing Arm | 14.5 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre Scaption in Non-Throwing Arm | 14.7 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post Scaption in Non-Throwing Arm | 14.3 kg | Standard Deviation 0.5 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 0 in Throwing Arm | 15.9 kg | Standard Deviation 0.8 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post ER at 0 in Throwing Arm | 15.8 kg | Standard Deviation 0.8 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 0 in Non-Throwing Arm | 16.0 kg | Standard Deviation 0.8 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post ER at 0 in Non-Throwing Arm | 15.9 kg | Standard Deviation 0.8 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 0 in Throwing Arm | 24.3 kg | Standard Deviation 1.2 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post IR at 0 in Throwing Arm | 25.4 kg | Standard Deviation 1.2 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 0 in Non-Throwing Arm | 24.1 kg | Standard Deviation 1.2 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post IR at 0 in Non-Throwing Arm | 24.4 kg | Standard Deviation 1.2 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 90 in Throwing Arm | 19.7 kg | Standard Deviation 1.3 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post ER at 90 in Throwing Arm | 17.3 kg | Standard Deviation 1.3 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre ER at 90 in Non-Throwing Arm | 20.0 kg | Standard Deviation 1.3 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post ER at 90 in Non-Throwing Arm | 17.8 kg | Standard Deviation 1.3 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 90 in Throwing Arm | 19.7 kg | Standard Deviation 1.3 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Post IR at 90 in Throwing Arm | 22.1 kg | Standard Deviation 1.3 |
| General Population, Experimental: BFR | Isometric Rotator Cuff Strength in Pitchers | Pre IR at 90 in Non-Throwing Arm | 19.9 kg | Standard Deviation 1.4 |
Secondary
Strength Endurance in General Population
repetitions to fatigue (RTF) were performed for 3 exercises. Volume (repetitions x resistance, kg) was calculated for each trial as is common for strength training investigations. After strength testing, participants were asked to perform the first of 2 endurance tests separated by 48 to 72 hours. On both occasions, a single set of repetitions to fatigue (RTF) were performed for 3 exercises in the following order: standing cable ER at 0 of shoulder abduction, standing cable IR at 0, and dumbbell scaption with each exercise separated by a 2-minute rest period and alternating between arms (order randomized). This test was performed in both groups with and without 50% limb occlusion pressure (LOP) applied by an automated tourniquet system. A nylon cuff was placed around the most proximal portion of the upper extremity for all testing. The order of testing was randomized between the 2 testing days for each participant.
Time frame: Baseline and 8 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable ER - Pre at 50% LOP | 97.3 kg | Standard Deviation 10.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable ER Post at 50% LOP | 155.1 kg | Standard Deviation 10.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable IR - Pre at 50% LOP | 230.7 kg | Standard Deviation 19.5 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable IR - Post at 50% LOP | 305.9 kg | Standard Deviation 19.5 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Scaption - Pre at 50% LOP | 134.8 kg | Standard Deviation 18.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Scaption - Post at 50% LOP | 211.2 kg | Standard Deviation 18.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable ER - Pre without LOP | 99.5 kg | Standard Deviation 12.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable ER Post without LOP | 157.2 kg | Standard Deviation 10.7 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable IR - Pre at without LOP | 249.1 kg | Standard Deviation 17.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Cable IR - Post at without LOP | 342.2 kg | Standard Deviation 17.8 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Scaption - Pre at without LOP | 138.6 kg | Standard Deviation 18.3 |
| General Population, No Intervention: Control | Strength Endurance in General Population | Scaption - Post without LOP | 222.7 kg | Standard Deviation 18.4 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Scaption - Pre at without LOP | 140.2 kg | Standard Deviation 18.4 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable ER - Pre at 50% LOP | 94.1 kg | Standard Deviation 10.9 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable ER - Pre without LOP | 96.2 kg | Standard Deviation 10.8 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable ER Post at 50% LOP | 155.1 kg | Standard Deviation 10.9 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable IR - Post at without LOP | 407 kg | Standard Deviation 17.9 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable IR - Pre at 50% LOP | 230.9 kg | Standard Deviation 19.5 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable ER Post without LOP | 155.9 kg | Standard Deviation 10.8 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable IR - Post at 50% LOP | 389.5 kg | Standard Deviation 19.6 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Scaption - Post without LOP | 231.7 kg | Standard Deviation 18.4 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Scaption - Pre at 50% LOP | 137 kg | Standard Deviation 18.9 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Cable IR - Pre at without LOP | 249.3 kg | Standard Deviation 17.9 |
| General Population, Experimental: BFR | Strength Endurance in General Population | Scaption - Post at 50% LOP | 240.3 kg | Standard Deviation 18.8 |