Blood Flow Restriction at High Resistance Loads Increases the Rate of Muscular Fatigue, but Does Not Increase Plasma Markers of Myotrauma or Inflammation.

Winchester, LJ, Morris, CE, Badinger, J, Wiczynski, TL, and VanWye, WR. Blood flow restriction at high resistance loads increases the rate of muscular fatigue, but does not increase plasma markers of myotrauma or inflammation. J Strength Cond Res 34(9): 2419-2426, 2020-High-load resistance training and blood flow restriction (BFR) training at low loads both promote protein synthesis and growth through different cell signaling mechanisms. Therefore, co-activation of these pathways could result in a synergistic effect for additional growth enhancement. The purpose of this study was to evaluate how BFR effects performance and physiological responses after an acute bout of high-load barbell squat training. Twelve resistance-trained, college-aged men and women performed 5 sets of barbell squats at 75% of 1 repetition maximum until failure under traditional (TRAD; control) or intermittent BFR conditions. Perceived limb pain and number of repetitions performed were recorded after each set. Blood samples were collected at baseline and 1-hour postexercise after each trial for analysis of myoglobin and interleukin-6 (IL-6). An alpha level of p < 0.05 was used to determine significance. Blood flow restriction trial performance significantly declined at set 3 and was lower than performance during control, whereas control performance did not decrease until set 5. Perceived limb pain was statistically increased with BFR use for the whole trial and was significantly higher with BFR during set 3 than observed during TRAD. Plasma myoglobin and IL-6 were significantly increased after both trials when compared with baseline, but were not significantly different between trials. Intermittent BFR use during high-load barbell squats increases the rate of muscular fatigue and perceived limb pain, but does not increase muscular damage or inflammatory response. Data obtained from this study can be used by fitness professionals as a means of potentially enhancing the rate of muscular hypertrophy.

Cardiovascular Responses During Light-intensity Aerobic Exercise with Varying Levels of Limb Occlusion Pressures.

The study aimed to assess cardiovascular responses to low-intensity aerobic exercise with varying levels of limb occlusion pressures (LOP) in a healthy population of men and women 30 to 60 years. The study was a single-session repeated measures design. Thirty individuals completed the study. All subjects participated in a single bout of low-intensity cycling (30-39% HRR) with bilateral lower extremity (LE) BFR for four 5-minute stages [0% (No BFR), 40%, 60%, and 80% LOP] with a 2-minute active rest between stages (BFR pressure released). The subjects' systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SpO2), and ratings of perceived exertion (RPE) were measured at rest, peak, immediately post, post-15 minutes, and post-30 minutes. Peak SBP (no BFR 160.7 ±19.1 mmHg; 40% LOP 173.6 ± 18.7 mmHg; 60 % LOP; 182.5 ± 21.1 mmHg; 80% LOP 193.5± 23.3 mmHg ; p<0.001; ηP2=.747), DBP (no BFR 74.9 ± 8.5 mmHg; 40% LOP (83.0 ± 9.0 mmHg;60 % LOP 90.4 ± 8.7 mmHg; 80% LOP 97.7 ± 9.5 mmHg ;p<0.001; ηP2=.924), MAP (no BFR 103.5 ± 10.1 mmHg; 40% LOP 113.2 ± 10.5 mmHg; 60% LOP 121.1 ± 11.7 mmHg; 80% LOP 129.7 ± 12.9 mmHg; p<0.001; ηP2=.960), and RPE (No BFR 10.0 ± 2.0; 40 % LOP 11.5 ± 2.3; 60% LOP 13.2 ± 2.6; 80% LOP 14.5 ± 3.; p<0.001; ηP2=.826) were significantly higher with each progressing stage. The results indicate that low-intensity cycling with bilateral LE BFR for each LOP stage resulted in elevated SBP, DBP, MAP, and RPE despite maintaining a fixed HR.

Acute Changes in Arterial Function Post High-Intensity Lower Extremity Cycling.

The purpose of this study was to assess the acute arterial blood flow velocity of the lower extremity (LE) immediately after a bout of high-intensity LE cycling exercise. Twenty-eight healthy males (n = 14) and females (n = 14) aged 20.9 ± 1.7 years participated in this study. All subjects performed a single bout of high-intensity cycling (70% of HRR) for 45 min. The subjects' LE blood flow velocity, heart rate (HR), systolic blood pressure (SBP), and oxygen saturation (SpO2) were measured at rest, immediately post-, post-15 min., and post- 30 min. intervention. A repeated-measures ANOVA with a Bonferroni adjustment was used for each measure to compare the responses at each time point. Resting blood flow velocity (37.5 ± 11.3 cm/s) and HR (64.9 ± 11.8 bpm) measures were significantly different (p < 0.05) compared to measures of immediately post cycling (44.8 ± 13.7 cm/s; 118.3 ± 17.2 bpm), post-15 min. (50.1 ± 15.0 cm/s; 80.1 ± 12.0 bpm) and post-30 min. (52.7 ± 18.1 cm/s; 73.9 ± 11.9 bpm). SBP measures were significantly different (p < 0.05) at immediately post (118.2 ±17.0 mmHg) compared to post-15 min. (108.1 ± 13.6 mmHg). Resting SpO2 (98.2 ± 1.3 %) measures were significantly different (p < 0.05) compared to measures immediately post (96.5 ± 1.1 %) and post-15 min. (96.9 ± 1.2 %). This study indicates that LE blood flow velocity was increased, and HR was elevated following a single bout of high-intensity LE cycling up to 30 min.-post. Additionally, SBP was elevated, while SpO2 dropped following a bout of exercise to 15 min.-post activity.

Effects of quadriceps and hamstrings proprioceptive neuromuscular facilitation stretching on knee movement sensation.

Stretching before competition has traditionally been thought to benefit performance; however, recent evidence demonstrating reduced muscle force and power immediately after stretching suggests otherwise. We hypothesized that knee joint position sense would be diminished immediately after proprioceptive neuromuscular facilitation (PNF) stretching to the hamstrings and quadriceps. Eighteen subjects (aged 18-30 years) were seated with their dominant foot attached to a motorized arm with the knee flexed at 135 degrees . To block external cues, the subjects wore a blindfold, earplugs, and headphones providing white noise. The knee was displaced in either the flexion or the extension direction at a velocity of 0.4 degrees .s, and subjects pressed a button when they sensed motion. The knee was returned to 135 degrees , and the test was repeated for a total of 10 trials. The PNF group received PNF stretching to the hamstrings and quadriceps of the dominant leg. The SHAM group had the dominant leg passively moved within each subject's functional range of motion. The ability to detect knee movement was retested in the PNF and SHAM groups. Pre- and posttest latencies between movement onset and subject response were analyzed. Results indicated that the PNF group had significantly increased latencies after stretching (from 2.56 +/- 0.83 to 3.46 +/- 1.90 seconds) compared with the SHAM group (3.93 +/- 2.40 to 3.72 +/- 2.15 seconds). It is concluded that PNF stretching of the hamstrings and quadriceps may acutely diminish sensitivity to knee movement. For coaches and trainers, these findings are consistent with previous reports of loss in muscle force and power immediately after stretching, suggesting that stretching just before competition may diminish performance.

Sport simulation as a form of implicit motor training in a geriatric athlete after stroke: a case report.

Background and Purpose: To describe the use of sport simulation activities as a form of implicit motor learning training with a geriatric former athlete following a stroke.Case Report: An active 76-year-old former professional male softball player presented to outpatient physical therapy with medical history of right stroke with left hemiparesis 2 weeks following onset of symptoms of impaired balance, coordination, gait, and motor planning. Initial physical therapy included gait, balance, and coordination training. Additional sport-related balance and coordination activities were later added to the treatment plan.Outcomes: After approximately 3 weeks of treatment, the patient was able to return to work and had dramatically improved balance, coordination, and gait with sport simulation activities.Discussion: Implicit motor learning techniques were incorporated through sport and job task simulation activities along with task-oriented neuromuscular reeducation. The patient demonstrated improvements with gait, balance, gross motor function, and decreased fall risk.

The Effect of Cuff Width for Determining Limb Occlusion Pressure: A Comparison of Blood Flow Restriction Devices.

The purpose of this study was to compare the standing lower extremity limb occlusion pressure (LOP) between two units. It was hypothesized that the Delfi unit, which utilizes a wider cuff (11.5 cm), would require significantly less LOP as compared to the KAASTU unit, which utilizes a narrow cuff (5 cm). Twenty-nine healthy participants (22 men, 7 women) mean age 24 years old (± 1.7 SD) volunteered. The procedure was identical for each cuff, completed with 5 minutes of rest in between. The cuff was placed on the proximal left thigh in the standing position. The initial pressure was set to 50 mmHg and then increased in 50 mmHg increments until complete arterial occlusion was achieved or the unit went to its maximum pressure. Arterial blood flow was determined by a mobile ultrasound measured at the left popliteal artery. Paired samples t-tests were used to determine differences in LOP (mmHg) between the Delfi and KAATSU unit cuffs. Significant differences were observed between the cuffs (wide: 239.4 mmHg vs. narrow: 500 mmHg; p < 0.001). We were able to achieve complete arterial occlusion with the wide cuff. The KAATSU unit reached maximum pressure with all participants, therefore we were unable to achieve complete arterial occlusion with the narrow cuff. Although achieving complete arterial occlusion is not indicated or safe for BFR training, relative pressures are used and determined as a percentage of LOP. Our study found that the relative pressure of the wide cuff is lower than the narrow cuff.

Differential diagnosis of knee pain following a surgically induced lumbosacral plexus stretch injury. A case report.

Background and Purpose: Knee joint biomechanics requires an understanding of lower extremity (LE) segmental interactions. In some cases, knee pain may arise as a result of altered LE biomechanics; while in other cases, knee pain may stem from other causes, such as a peripheral nerve injury. Case Description: A 33-year-old woman presented via direct access for physical therapist (PT) examination with a chief complaint of left knee pain. The day after undergoing a dilation and curettage (D&C) procedure the patient had an acute onset of gait dysfunction. Over the next few days, the patient developed left anterior knee pain (7/10 at worst) in addition to a significant change in physical functioning (Lower Extremity Functional Scale [LEFS] 38/80). Physical examination revealed left LE weakness, altered sensation, and an absent Achilles deep tendon reflex. Outcomes: The patient's presentation was consistent with a lumbosacral plexus stretch injury, with S1 being most affected. A physiatrist was consulted and recommended initiating PT treatment with bi-weekly re-examination. The 6-week (14 visits) re-examination revealed abolished left knee pain and improved physical functioning (LEFS 66/80). Conclusion: Stretch injuries are a known complication of lithotomy positioning. Knowledge of this and the addition of a thorough examination allowed the PT to identify the possible cause of the patient's abrupt onset of left LE dysfunction. Regardless of mode of patient access, screening for referral is crucial and may include referral or, as in this case, consultation with other professionals.

Factors Affecting PhD Student Success.

Attrition rates for Doctor of Philosophy (PhD) programs in the United States across the fields of engineering, life sciences, social sciences, mathematics and physical sciences, and humanities range from 36 - 51%. A qualitative literature review indicates certain factors may impact the PhD student's success in completing the program and degree. The factors focused on in this review include the student-advisor relationship, mentorship, and the dissertation process. Although kinesiology doctoral programs are evaluated and ranked by the National Academy of Kinesiology, little information is available exploring kinesiology PhD student success. General information on PhD student success may, therefore, be valuable to kinesiology PhD students and programs.

Management of a patient's gait abnormality using smartphone technology in-clinic for improved qualitative analysis: A case report.

BACKGROUND AND PURPOSE: Qualitative analysis has its limitations as the speed of human movement often occurs more quickly than can be comprehended. Digital video allows for frame-by-frame analysis, and therefore likely more effective interventions for gait dysfunction. Although the use of digital video outside laboratory settings, just a decade ago, was challenging due to cost and time constraints, rapid use of smartphones and software applications has made this technology much more practical for clinical usage. CASE DESCRIPTION: A 35-year-old man presented for evaluation with the chief complaint of knee pain 24 months status-post triple arthrodesis following a work-related crush injury. In-clinic qualitative gait analysis revealed gait dysfunction, which was augmented by using a standard IPhone® 3GS camera. After video capture, an IPhone® application (Speed Up TV®, https://itunes.apple.com/us/app/speeduptv/id386986953?mt=8 ) allowed for frame-by-frame analysis. Corrective techniques were employed using in-clinic equipment to develop and apply a temporary heel-to-toe rocker sole (HTRS) to the patient's shoe. OUTCOMES: Post-intervention video revealed significantly improved gait efficiency with a decrease in pain. The patient was promptly fitted with a permanent HTRS orthosis. This intervention enabled the patient to successfully complete a work conditioning program and progress to job retraining. DISCUSSION: Video allows for multiple views, which can be further enhanced by using applications for frame-by-frame analysis and zoom capabilities. This is especially useful for less experienced observers of human motion, as well as for establishing comparative signs prior to implementation of training and/or permanent devices.

Blood Flow Restriction Training: Implementation into Clinical Practice.

To improve muscular strength and hypertrophy the American College of Sports Medicine recommends moderate to high load resistance training. However, use of moderate to high loads are often not feasible in clinical populations. Therefore, the emergence of low load (LL) blood flow restriction (BFR) training as a rehabilitation tool for clinical populations is becoming popular. Although the majority of research on LL-BFR training has examined healthy populations, clinical applications are emerging. Overall, it appears BFR training is a safe and effective tool for rehabilitation. However, additional research is needed prior to widespread application.

Physical therapist screening and differential diagnosis for traumatic-onset elbow pain: A case report.

BACKGROUND AND PURPOSE: Elbow pain can originate from many sources yet have similar signs and symptoms, thereby presenting differential diagnostic challenges. The elbow is commonly injured, thus requiring all clinicians to possess excellent diagnostic skills. CASE DESCRIPTION: A 24-year-old woman slipped and fell on her outstretched left hand, experiencing immediate elbow pain. The same day radiographs were deemed negative by her orthopedist, who referred her to physical therapy with the diagnoses of elbow sprain and contusion. Immediately after examining the patient, the physical therapist consulted with the referring orthopedist. The decision to consult was based on: the mechanism of injury, pain severity out of proportion to the referred diagnoses, significantly limited ROM, abnormal joint end feels, exquisite pain with tactile and tuning fork bony palpation, and positive elbow extension test. OUTCOMES: The treating physical therapist shared the above-noted findings with the orthopedist, who overruled and recommended continuing the original prescription of non-steroidal anti-inflammatory medication and physical therapist treatment for four weeks. The physical therapist's updated plan of care at four weeks noted the patient's continued reports of pain, functional limitations, and disability. A magnetic resonance image (MRI) was then ordered, revealing a radial head fracture. DISCUSSION: A thorough history and examination by the physical therapist led to clustering of signs and symptoms, allowing for the development of a differential diagnosis list which included occult radial head fracture. All clinicians should be prepared to screen for complex conditions. Timely diagnosis and improved outcomes for clinically complex patients are increasingly necessary in contemporary healthcare reimbursement models.

Periodization and physical therapy: Bridging the gap between training and rehabilitation.

BACKGROUND: Exercise prescription and training progression for competitive athletes has evolved considerably in recent decades, as strength and conditioning coaches increasingly use periodization models to inform the development and implementation of training programs for their athletes. Similarly, exercise prescription and progression is a fundamental skill for sport physical therapists, and is necessary for balancing the physiological stresses of injury with an athlete's capacity for recovery. OBJECTIVE: This article will provide the sport physical therapist with an overview of periodization models and their application to rehabilitation. SUMMARY: In recent decades models for exercise prescription and progression also have evolved in theory and scope, contributing to improved rehabilitation for countless athletes, when compared to care offered to athletes of previous generations. Nonetheless, despite such advances, such models typically fail to fully bridge the gap between such rehabilitation schemes and the corresponding training models that coaches use to help athletes peak for competition. Greater knowledge of periodization models can help sport physical therapists in their evaluation, clinical reasoning skills, exercise progression, and goal setting for the sustained return of athletes to high level competition.

SCREENING FOR REFERRAL BY A SPORTS PHYSICAL THERAPIST REVEALS AN EFFORT THROMBOSIS IN A COLLEGIATE PITCHER: A CASE REPORT.

BACKGROUND AND PURPOSE: Screening for referral, regardless of setting, is the responsibility of all physical therapists. A serious condition that sports physical therapists may encounter is upper extremity (UE) deep venous thrombosis (DVT), which can result in the important and sometimes fatal complication of pulmonary embolism. CASE DESCRIPTION: A 22 year-old male right-hand dominant collegiate pitcher was referred for physical therapist evaluation and treatment secondary to acute right UE pain and swelling. The athlete described the onset of these symptoms as insidious, denying any form of trauma. The athlete had undergone testing, which included UE Doppler ultrasound of the bilateral UE veins and a computed tomography (CT) scan of the chest without contrast; both of which were deemed negative. He was subsequently diagnosed with thoracic outlet syndrome and referred to the team physical therapist. After examination, the physical therapist hypothesized the athlete was presenting with a possible vascular compromise. Findings leading to this decision were: 1) insidious onset, 2) inability to account for the athlete's pain with ROM, strength, neurological, or provocation testing, 3) significant swelling of the right UE (arm and forearm), 4) increased discomfort with palpation in the supraclavicular region, and 5) history of strenuous UE use. OUTCOMES: The athlete was referred back to the orthopedist. A venogram CT was ordered, which revealed an axillary and subclavian DVT and the presence of venous collaterals. The athlete was referred to a vascular surgeon who performed a right first rib removal. The athlete was able to complete post-operative rehabilitation and successfully return to competitive throwing the following spring. DISCUSSION: The delay in the initial diagnosis may have been due to the vague symptomology associated with venous complications and negative findings upon initial diagnostic testing. CONCLUSION: This case report highlights the importance of subjective and physical examination findings and use of diagnostic testing for timely identification of an UE DVT. Ultimately, the physical therapist in this case was able to screen for referral, which led to the correct diagnosis and allowed the athlete to safely and successfully return to sport. Physical therapists should include effort thrombosis in their upper quarter differential diagnosis list for athletes who perform strenuous UE activity. LEVEL OF EVIDENCE: 4.

Nonspecific low back pain: evaluation and treatment tips.

Avoid imaging in cases of uncomplicated low back pain (unless there are specific clinical indications). Use acetaminophen, nonsteroidal anti-inflammatory drugs, or muscle relaxants for short-term relief of acute nonspecific low back pain. Consider matching specific physical therapy options to the patient's history and exam findings.

Patient screening by a physical therapist for nonmusculoskeletal hip pain.

BACKGROUND AND PURPOSE: Mechanical hip pain and disease-based hip pain can have similar signs and symptoms, thereby presenting a differential diagnostic challenge for clinicians. Hip pain is a common complaint addressed by physical therapists; therefore, it would be advantageous for them to be knowledgeable about differential diagnosis for hip pain, so that they can screen for possible serious conditions outside the realm of physical therapist practice and make the appropriate referral. CASE DESCRIPTION: A 77-year-old man was referred for physical therapy by his primary care physician (PCP) with diagnoses of lumbar spine and left hip osteoarthritis and possible trochanteric bursitis. After the examination, the physical therapist determined that the patient should return to his PCP for further testing. Findings leading to this conclusion were pain severity out of proportion to the reported injury, the presence of night pain, a positive "sign of the buttock," and empty end feels of all hip joint motions, which represented a noncapsular pattern of joint restriction. OUTCOMES: The patient was diagnosed later with primary lung adenocarcinoma with widespread metastases. A computerized tomography scan of the left hip revealed a metastatic lesion at the left proximal femur. DISCUSSION: Physical therapists' ability to adequately screen for conditions requiring examination by a physician can lead to a more timely diagnosis of serious medical conditions. Investigators have found published descriptions of end feels, capsular versus noncapsular patterns of restriction, and the sign of the buttock to be beneficial screening tools for use in people with hip, pelvis, or lumbar spine pain.