KAATSU Cuff Tightness and Limb Anthropometry: Effect on Blood Flow Restriction

abstractKAATSU resistance training involves low loads (20%1RM) and partial blood flow restriction (BFR). When applying a BFR cuff, the initial cuff tightness (ICT) is important. ICTs can potentially impact the degree of BFR (%BFR) caused by the subsequent inflation to the target training pressures. It’s known that limb anthropometrics can affect the amount of BFR that is produced at specific pressures. Understanding the interaction between limb anthropometrics and ICT is an important first step in standardizing BFR dose between individuals for KAATSU training prescription. Purpose: To determine what limb anthropometrics (circumference, muscle or fat composition) have the greatest effect on %BFR with various ICTs. Methods: Forty-two volunteers (26 men, 16 women) provided informed consent. Caliper skin folds (anterior and posterior), Gulick tape circumferences, and peripheral quantitative computed tomography (pQCT) scans were performed on the randomly assigned ipsilateral arm and leg at the level of the KAATSU cuff. %BFR was measured via pulse-wave Doppler ultrasound at baseline (no cuff) and at 5 ICT pressures (20, 30, 40, 50 and 60mmHg). Variable relationships were assessed using Pearson correlations and stepwise linear regression. Results: The dependent variable for regression analysis was %BFR at each ICT. pQCT-determined muscle (R2= .147, .614, .445, .360, & .232, respectively) and fat composition (R2= .138, .587, .429, .338, & .220, respectively) were significant (p<.05) determinants of BFR at all ICT pressures in the arm. At 30mmHg, circumference was also a determinant (R2=.163). There were no significant correlations between %BFR and any of the ICT pressures for the leg. pQCT fat composition and sum of skin folds correlated significantly (r=.915, p<.05). pQCT circumference and Gulick circumference measures correlated significantly (r=.991, p<.05). Conclusion: Arm anthropometrics impact the %BFR created by 5 ICTs in the arm. Skin fold measures and circumference measures were highly correlated with pQCT data. As a result, skin fold and Gulick circumference measures can be used to predict arm composition at the level of the cuff and may inform prescription of appropriate ICTs that result in more consistent initial %BFR across individuals

Initial KAATSU Cuff Tightness: Effect of Limb Anthropometrics on Blood Flow Restriction

abstractINTRODUCTION KAATSU training involves low load (20%1RM) resistance exercise combined with partial blood flow restriction (BFR). BFR is achieved by positioning a specially designed pneumatic cuff around the proximal aspect of the limb, cinching it to an initial cuff tightness (ICT), then inflating the cuff to a higher restrictive training pressure. ICTs can potentially impact the degree of BFR (%BFR) caused at the higher training pressures, yet many studies use the same ICTs for all subjects (1). Identifying that discrepancies in %BFR exist between subjects with different limb anthropometrics is an important step in moving toward standardization of BFR dose for KAATSU training prescription. The purpose of this study was to identify variation in %BFR between subjects experiencing the same ICT and what limb anthropometrics (circumference, muscle, and fat composition) may be determinants. METHODS Forty-two volunteers (26 men, 16 women) provided informed consent. Caliper skin folds, Gulick tape circumferences, and peripheral quantitative computed tomography (pQCT) scans were performed on the randomly assigned ipsilateral arm and leg at the level of the KAATSU cuff application. %BFR was measured via pulse-wave Doppler ultrasound at baseline (no cuff) and at an ICT of 30 mmHg. Variable relationships were assessed using Pearson correlations and stepwise linear regression. RESULTS The average %BFR (avg±st. dev.) for the arm and leg was 16.01±11.42% and 16.75±9.27% with a range of 46.66% and 36.41%, respectively. The dependent variable for regression analysis was %BFR. In the arm, pQCT-determined muscle (R2=0.614) and fat composition (R2=0.587) were significant (p<0.05) determinants of %BFR. Circumference was also a determinant (R2=0.163). There were no significant correlations between %BFR and the anthropometrics for the leg. pQCT fat composition and sum of skin folds correlated significantly (r=0.915, p<0.05). pQCT circumference and Gulick circumference measures correlated significantly (r=0.991, p<0.05). DISCUSSION Conflicting BFR training results have been reported in the literature. A potential cause could be universal ICT usage causing some individuals to receive an inadequate training stimulus. Individuals using a 30 mmHg ICT will experience different %BFR when limb anthropometrics vary. Thus a method of assigning ICTs specific to individuals’ anthropometric characteristics is needed to ensure equally potent stimuli. Skin fold measures and circumference measures were highly correlated with pQCT data. As a result, skin fold and Gulick circumference measures can be used to predict arm composition at the level of the cuff and may inform prescription of appropriate ICTs that result in more consistent initial %BFR across individuals

EFFECTS OF KAATSU TRAINING ON UPPER EXTREMITY SIZE AND STRENGTH

poster abstractConventional resistance training involves lifting heavy loads (~70% max-imal strength), which can be poorly tolerated or contraindicated in many clinical populations. KAATSU training is a novel training mode from Japan that combines muscle blood flow restriction with low load lifting (~20% max-imal strength). The purpose of this study was to investigate the effects of a KAATSU training program on upper extremity size and strength. Forty healthy subjects ages 18 to 30 were divided into exercise (EX) or control (CON) groups. Subjects reported to the laboratory three times per week for eight weeks. The EX group performed 3 sets of 15 repetitions of unilateral bicep curls and triceps extensions lifting loads equivalent to 20% of their predetermined maximal strength while wearing a pneumatic cuff to restrict blood flow on one arm (CUFF) and nothing on the other (NCUFF). The CON group did not perform any exercises but wore the cuff on one arm for a time comparable to the EX group. CUFF and NCUFF arms were randomly as-signed. Strength, girth, skin folds and tomography scans were taken pre-, during, and post-eight weeks. In the EX group, bicep curl (17.4% +4.1% and 18.7% +4.9%) and triceps extension (15.8% +3.4% and 10.7% +2.7%) strength increased significantly over the 8-week period for both the CUFF and NCUFF arms, respectively. No significant differences in strength occurred between the CUFF and NCUFF arms within the group. No strength changes were noted in the CON group for the CUFF and NCUFF arms. Arm girth and muscle cross-sectional area (mCSA) increased significantly in the EX subjects compared to the CON subjects, however no significant differ-ences were found when within group comparisons were made between the CUFF and NCUFF arms. This study indicates that KAATSU training can in-crease muscle strength and mCSA

KAATSU TRAINING: PERCEPTIONS AND COMPLIANCE TO AN UPPER ARM EXERCISE PROGRAM

poster abstractKAATSU training is a novel Japanese training mode involving low load (~20% maximal strength) weightlifting combined with blood flow restriction to the muscles. Little is known about the sensations experienced during KAATSU training and whether clients will tolerate it. The purpose of this study was to assess perceived sensations, exertion rates, and compliance to an upper arm KAATSU training program. Forty healthy subjects ages 18 to 30 were divided into exercise (EX) or control (CON) groups. Subjects report-ed to the laboratory three times per week for eight weeks. The EX group performed 3 sets of 15 repetitions of unilateral bicep curls and triceps exten-sions lifting loads equivalent to 20% of their predetermined maximal strength while wearing a pneumatic cuff on one arm (CUFF) and nothing on the other (NCUFF). The CON group did not perform any exercises but wore the cuff on one arm for a time comparable to the EX group. CUFF and NCUFF arms were randomly assigned. Sensations (burning, aching, pressure, pins & needles) and perceived exertion were assessed using visual analog scales that included emotions and verbal cues. Compliance (percentage of subjects completing the pre- and post-testing) and adherence (percentage of ses-sions completed) were tracked to provide an indication of training tolerance. Compliance was 85.4% and 97% for the EX and CON groups, respectively. EX subjects completed 85.4% of their workouts while controls attended 90.4% of their sessions. The prominent sensation reported in the CUFF arm was pressure (moderate; 3.2 +0.6) followed by aching (weak; 1.7 +0.4). Ratings of perceived exertion were higher for the CUFF (3.2 +1.0, 5.1 +1.8, and 7.0 +2.5) versus NCUFF (1.5 +0.3, 2.4 +0.3, and 3.3 +0.4) arm for sets 1, 2, and 3, respectively. KAATSU training is well tolerated by those performing it and a viable alternative to conventional resistance exercise

The effects of hip muscle strengthening on knee load, pain, and function in people with knee osteoarthritis: a protocol for a randomised, single-blind controlled trial

BACKGROUND: Lower limb strengthening exercises are an important component of the treatment for knee osteoarthritis (OA). Strengthening the hip abductor and adductor muscles may influence joint loading and/or OA-related symptoms, but no study has evaluated these hypotheses directly. The aim of this randomised, single-blind controlled trial is to determine whether hip abductor and adductor muscle strengthening can reduce knee load and improve pain and physical function in people with medial compartment knee OA. METHODS/DESIGN: 88 participants with painful, radiographically confirmed medial compartment knee OA and varus alignment will be recruited from the community and randomly allocated to a hip strengthening or control group using concealed allocation stratified by disease severity. The hip strengthening group will perform 6 exercises to strengthen the hip abductor and adductor muscles at home 5 times per week for 12 weeks. They will consult with a physiotherapist on 7 occasions to be taught the exercises and progress exercise resistance. The control group will be requested to continue with their usual care. Blinded follow up assessment will be conducted at 12 weeks after randomisation. The primary outcome measure is the change in the peak external knee adduction moment measured during walking. Questionnaires will assess changes in pain and physical function as well as overall perceived rating of change. An intention-to-treat analysis will be performed using linear regression modelling and adjusting for baseline outcome values and other demographic characteristics. DISCUSSION: Results from this trial will contribute to the evidence regarding the effect of hip strengthening on knee loads and symptoms in people with medial compartment knee OA. If shown to reduce the knee adduction moment, hip strengthening has the potential to slow disease progression. TRIAL REGISTRATION: Australia New Zealand Clinical Trials Registry ACTR12607000001493

Strength Training for Arthritis Trial (START): design and rationale

Background Muscle loss and fat gain contribute to the disability, pain, and morbidity associated with knee osteoarthritis (OA), and thigh muscle weakness is an independent and modifiable risk factor for it. However, while all published treatment guidelines recommend muscle strengthening exercise to combat loss of muscle mass and strength in knee OA patients, previous strength training studies either used intensities or loads below recommended levels for healthy adults or were generally short, lasting only 6 to 24 weeks. The efficacy of high-intensity strength training in improving OA symptoms, slowing progression, and affecting the underlying mechanisms has not been examined due to the unsubstantiated belief that it might exacerbate symptoms. We hypothesize that in addition to short-term clinical benefits, combining greater duration with high-intensity strength training will alter thigh composition sufficiently to attain long-term reductions in knee-joint forces, lower pain levels, decrease inflammatory cytokines, and slow OA progression. Methods/Design This is an assessor-blind, randomized controlled trial. The study population consists of 372 older (age ≥ 55 yrs) ambulatory, community-dwelling persons with: (1) mild-to-moderate medial tibiofemoral OA (Kellgren-Lawrence (KL) = 2 or 3); (2) knee neutral or varus aligned knee ( -2° valgus ≤ angle ≤ 10° varus); (3) 20 kg.m-2 ≥ BMI ≤ 45 kg.m-2; and (3) no participation in a formal strength-training program for more than 30 minutes per week within the past 6 months. Participants are randomized to one of 3 groups: high-intensity strength training (75-90% 1Repetition Maximum (1RM)); low-intensity strength training (30-40%1RM); or healthy living education. The primary clinical aim is to compare the interventions’ effects on knee pain, and the primary mechanistic aim is to compare their effects on knee-joint compressive forces during walking, a mechanism that affects the OA disease pathway. Secondary aims will compare the interventions’ effects on additional clinical measures of disease severity (e.g., function, mobility); disease progression measured by x-ray; thigh muscle and fat volume, measured by computed tomography (CT); components of thigh muscle function, including hip abductor strength and quadriceps strength, and power; additional measures of knee-joint loading; inflammatory and OA biomarkers; and health-related quality of life. Discussion Test-retest reliability for the thigh CT scan was: total thigh volume, intra-class correlation coefficients (ICC) = 0.99; total fat volume, ICC = 0.99, and total muscle volume, ICC = 0.99. ICC for both isokinetic concentric knee flexion and extension strength was 0.93, and for hip-abductor concentric strength was 0.99. The reliability of our 1RM testing was: leg press, ICC = 0.95; leg curl, ICC = 0.99; and leg extension, ICC = 0.98. Results of this trial will provide critically needed guidance for clinicians in a variety of health professions who prescribe and oversee treatment and prevention of OA-related complications. Given the prevalence and impact of OA and the widespread availability of this intervention, assessing the efficacy of optimal strength training has the potential for immediate and vital clinical impact