EFFECT OF BLOOD FLOW RESTRICTION TRAINING ON MUSCULAR PERFORMANCE, PAIN AND VASCULAR FUNCTION

Background:Blood flow restriction (BFR) training enhances muscular strength and hypertrophy in several populations including older adults and injured athletes. However, the efficacy of emerging BFR technologies on muscular adaptations, vascular health, and pain is unclear.Purpose:The purpose of this study was to examine muscular performance, pain and vascular function in response to eight weeks of BFR compared to traditional resistance training and a control group.Study Design:Randomized control trialMethods:Thirty-one overtly healthy participants (age: 23 ± 4y, 65% female) underwent eight weeks of supervised high load resistance training (RES), low load resistance training with BFR (BFR) or no training (control, CON). RES and BFR (with pneumatic bands) performed seven upper and lower body exercises, two to three sessions per week at 60% and 30% of one-repetition maximum (1RM), respectively. Twenty-four hours post-exercise, general muscle soreness was assessed via a visual analog scale (VAS) and present pain intensity (PPI) of the McGill Pain Questionnaire. At baseline and after eight weeks, participants underwent one-repetition maximum (1RM), and flow-mediated dilation (FMD) testing.Results:At baseline all groups exhibited similar muscle strength and endurance and vascular function. At the end of training, RES and BFR groups significantly increased muscle strength (1RM) to a similar magnitude as compared to the CON group (p < 0.0001), but did not alter body composition. FMD significantly increased in RES and BFR groups compared to CON group (p = 0.006). VAS and PPI were similar between RES and BFR groups throughout the exercise sessions until VAS decreased in the BFR group after the last session compared to the RES group (p = 0.02).Conclusion:Compared to RES, BFR resulted in similar muscular performance (strength and endurance) and vascular improvements at a lower exercise intensity, suggesting BFR is an effective alternative to high load resistance training. Further longitudinal studies may gain greater understanding regarding general muscle pain and soreness when using BFR.Level of Evidence:Therapy, Level 2     

A SYSTEMATIC REVIEW OF THE EFFECTS OF BLOOD FLOW RESTRICTION TRAINING ON QUADRICEPS MUSCLE ATROPHY AND CIRCUMFERENCE POST ACL RECONSTRUCTION

Background:ACL reconstruction often results in an extended period of muscle atrophy and weakness. Blood flow restriction (BFR) training is a technique that has been shown to decrease muscle atrophy in a variety of populations.Purpose:The purpose of this systematic review was to analyze the research presented on the effect of blood flow restriction training on quadriceps muscle atrophy and circumference post ACL reconstruction.Study Design:Systematic ReviewMethods:Articles were reviewed using the databases Google Scholar, PubMed, and EBSCO. Keywords included blood flow restriction training, ACL reconstruction, and quadriceps.Inclusion criteria included:English language, peer-reviewed journals; randomized control trials; and articles including blood flow restriction and measurement of quadriceps atrophy and circumference post ACL reconstruction. Exclusion criteria included non-English language publications; studies without a control group; and articles without sufficient data to evaluate the methodology. Four studies met the selection criteria and were assessed using the GRADE scale, which analyzes the strength of a study based on study limitations, precision, consistency, directness, and publication bias. After a GRADE designation was assigned, the following information was extracted from and compared across the studies: participant demographics, cuff used, graft used during ACL reconstruction, tool used to assess muscle atrophy, protocol used, and conclusions.Results:Three out of four studies showed some amount of an increase in femoral muscle cross sectional area after the use of BFR combined with low-intensity resistance training (LIRT). The strength of all four studies was moderate when assessed using the GRADE scale.Conclusion:This review of the available evidence yields promising results regarding the use of BFR and LIRT in the remediation of femoral muscle atrophy after an ACL reconstruction. Further research is necessary before BFR can be recommended for use in clinical settings.Level of evidence:3a     

茶色素对高粘血症患者血液流变性和甲襞微循环的影响

高粘血症患者 ６４例,随机分为２组,治疗组３２例,口服茶色素 ２５０ｍｇ（２粒）,每日３次。对照组３２例,口服复方舟参片３片,每日３次,疗程均为 ３０天。结果：治疗组血液流变学各项指标中除血细胞压积变化不明显外,其它各项 均有显著改善（Ｐ＜０．０１）,而对照组中唯有血小板聚集率改善明显（Ｐ＜０．０５）。治 疗组对甲襞微循环四项积分亦明显改善（Ｐ＜０．０５式Ｐ＜０．０１）,而对照组改善不 显著（Ｐ＞０．０５）,未发现不良反应,故认为茶色素是治疗高粘血症患者的有效药 物。     

银质针治疗腰椎管外软组织损害后局部血流量变化观察

目的：观察银质针针刺疗法对局部病变软组织的血流影响并探讨其治痛机理。方法：本文对50例腰椎管外软组织损害患者,用血流图记录仪描述出银质针刺治疗前后和一个月的局部血流变化情况。结果：病变局部深层组织流量在针刺后增加50％以上,最高达150％,一个月时也较治疗前增加20％－40％。结论：改善局部深层病变组织血液循环是银质针治疗取得显著疗效的一个重要作用机理。     

EFFECTS OF A MOVEMENT TRAINING PROGRAM ON HIP AND KNEE JOINT FRONTAL PLANE RUNNING MECHANICS

Background/Purpose:

Frontal plane running mechanics may contribute to the etiology or exacerbation of common running related injuries. Hip strengthening alone may not change frontal plane hip and knee joint running mechanics. The purpose of the current study was to evaluate whether a training program including visual, verbal, and tactile feedback affects hip and knee joint frontal plane running mechanics among females with evidence of altered weight bearing kinematics.

Methods:

The knee frontal plane projection angle of 69 apparently healthy females was determined during a single leg squat. The twenty females from this larger sample who exhibited the most acute frontal plane projection angle (medial knee position) during this activity were chosen to participate in this study (age = 20 ± 1.6 years, height = 167.9 ± 6.0 cm, mass = 63.2 ± 8.3 kg, Tegner Activity Rating mode = 7.0). Participants engaged in a 4‐week movement training program using guided practice during weight bearing exercises with visual, verbal, and tactile feedback regarding lower extremity alignment. Paired t‐tests were used to compare frontal plane knee and hip joint angles and moments before and after the training program.

Results:

After training, internal hip and knee abduction moments during running decreased by 23% (P=0.007) and 29% (P=0.033) respectively. Knee adduction and abduction excursion decreased by 2.1° (P = 0.050) and 2.7° (P=0.008) respectively, suggesting that less frontal plane movement of the knee occurred during running after training. Peak knee abduction angle decreased 1.8° after training (P=0.051) although this was not statistically significant. Contralateral peak pelvic drop, pelvic drop excursion, peak hip adduction angle, hip adduction excursion, and peak knee adduction angle were unchanged following training.

Conclusions:

A four week movement training program may reduce frontal plane hip and knee joint mechanics thought to contribute to the etiology and exacerbation of some running related injuries.

Level of Evidence:

Level 4     

EFFECTS OF FOUR ANGIOTENSIN I CONVERTING ENZYME INHIBITORS ON REGIONAL MYOCARDIAL BLOOD FLOW AND ISCHEMIC INJURY DURING CORONARY ARTERY OCCLUSION IN DOGS

The effects of 4 angiotensin I converting enzyme inhibitors (ACEI), captopril, enalapril, ramipril, and trandolapril, were investigated on regional myocardial blood flow (RMBF, radioactive microspheres) distribution in ischemic and nonischemic zones and on ST-segment elevation in ischemic zones during intermittent coronary artery occlusion in anesthetized dogs. The 4 ACEI inhibited plasma ACE activity to an almost similar extent. All similarly reduced systemic blood pressure, an effect related to a decrease in systemic vascular resistance. Heart rate and myocardial contractility were not affected, but myocardial oxygen consumption presumably decreased because of the reduction in afterload. RMBF and their distribution (between epicardial and endocardial layers and between nonischemic and ischemic zones) were not modified by ACEI. Coronary vascular resistance was slightly decreased in nonischemic zones. ACEI had no effect on ST-segment elevation in ischemic zones. Thus, in this experimental model, all ACEI exhibited the same profile, including no change in RMBF and affording no protection against ischemic injury.     

EFFECTS OF PROPRANOLOL AND SWIM-TRAINING ON BLOOD PRESSURE, PLASMA ELECTROLYTES, AND VASOPRESSIN IN SPONTANEOUSLY HYPERTENSIVE AND NORMOTENSIVE RATS

The aim of this work was to study the influence of beta-adrenoreceptor blockade on the adaptation to exercise of one of the hormonal systems (arginine vasopressin) involved in the regulation of blood volume and pressure in spontaneously hypertensive rats (SHR). Systolic blood pressure (SBP) was measured in SHR and WKY rats during 11 wk of swim training. At the end of the training program we determined post-exercise values of plasma arginine-vasopressin (pAVP), osmolality (pOsm), K+ (pK+), Na+ (pNa+), hemoglobin (Hgb), and hematocrit (Hct) in SHR and WKY rats. The following groups were studied: control (C), propranolol treated (PC), swim trained (S), and propranolol-treated and swim-treated (PS). SBP was significantly reduced by swim training or propranolol, bu these beneficial effects on SBP were attenuated when propranolol and swim training were combined. pNa+ and pOsm were significantly reduced by training alone in SHR. This reduction of pNa+ and, consequently, of pOsmol without any modification of other parameters could suggest an Na+ loss. In contrast, the SHR group treated with propranolol alone showed a significant reduction in Hct, suggesting an increased plasma volume without Na+ loss. PS SHR showed a significant reduction of Hgb, Hct, proteins, pNa+, and pOsmol, probably as a consequence of the additive effects of swimming- and propranolol-induced hypervolemia with Na+ loss. The slight and nonsignificant reduction in pAVP observed with either training or propranolol treatment alone became much more pronounced and statistically significant when the 2 treatments were combined. WKY rats showed a much smaller response to exercise and beta-adrenoreceptor blockade than SHR. We conclude that the hypervolemia suggested in PS SHR could be a possible cause of attenuation of the beneficial effects of either swimming or propranolol on SBP.