Introduction

Skeletal muscle mass is a crucial factor for health, longevity, and maintaining the ability to complete activities of daily living, ambulate, and avoid falls. Muscle quantity and quality also directly impacts individuals in fitness and sport performance. A disuse of skeletal muscle can rapidly lead to atrophy of muscle tissue, resulting in reduced oxidation capacity, sarcomere shortening, and reduced muscle compliance. This in turn reduces exercise capacity, impairs the immune system, and decreases sensitivity to insulin.

Typically, high-intensity resistance training at 70-8% of a 1 repetition maximum (1-RM) is recommended to increase muscle mass and strength. However, this recommendation is often very challenging and even contraindicated for certain individuals such as those with underlying chronic medical conditions, rehabilitation patients, recovering athletes, or a post-operative population. Several studies have proposed the idea that Blood Flow Restricted (BFR) low load exercise (20-30% maximal capacity) may stimulate significant muscular adaptations, through use of an external constriction device. There has been a fast-growing body of literature for BFR training and the aim of this review is to systematically assess studies and identify which BFR training methods have the greatest results in strength and hypertrophy.

Methods

47 studies were identified to fit inclusion criteria of BFR with exercise stimulus compared to non BFR with exercise. Studies were required to include at least one of two outcomes: muscle strength or muscle size. These studies included all healthy participates with a mean age of 34. Studies were categorized into two exercise groups: aerobic and resistance training.

Results

Muscle Strength
The mean improvement in strength grains of experimental group with BFR aerobic exercise was 0.4nM above the strength changes in that of the control group. Training >6 weeks increased this mean difference to 0.6nM, compared to 0.2 nM in training <6 weeks. Typically, muscle strength in the BFR aerobic group was increased by 5-8 nM.

The mean improvement in strength gains of experiment group with BFR resistance exercise and control group was an additional 0.3 kg force. Gains in muscle strength were significantly greater when intensity of exercise was >20%1 RM versus <20% 1 RM. When comparing 20% 1 RM to 30% 1 RM, training at 30% 1 RM resulted in a much greater improvement in muscle strength. The mean difference between the experimental and control group were relatively small. Cuff pressure of >150 mmHG caused a greater increased in strength compared to cuff pressure <150 mmHg., 0.2 kg and 0.1 kg respectively.

Muscle hypertrophy
Aerobic training had a mean increase of post training muscle size of 0.32 cm^2 between control and experimental groups. The increase in size of muscle as a result of BFR Training was 0.41 cm^2 greater than that seen in the control groups.

Studies considering both modalities of exercise combined with BFR showed an increase in muscle size of 2-5 cm. Muscle size differences between the experimental and control group did vary when training took place 3 days per week compared to 2 days per week, 0.34 cm versus 0/29 cm respectively.

Discussion

The current research suggests BFR with low load exercise training is effective improving muscle strength and size. This was true for both aerobic and resistance training. When performing BFR aerobic exercise, training durations >6 weeks produced greater strength increases, which is the generally accepted adaption period for standard resistance training. Greater strength gains with BFR resistance training may be expected at an intensity >20% 1 RM.

Conclusion

This systematic review provides evidence of greater increases in muscle size and strength when exercise is combined with BFR, compared to low load exercise alone. This type of training offers potential benefits for populations recovering from orthopedic or other conditions that require rehabilitative care, for which higher load training is contraindicated. However, this study reveals there is a gap in the evidence in regards to optimal training methods and protocols, which would be important for future research.

Practical PTF Take-Aways

1. Lighter load BFR Training may be effective to increase muscle size and strength when traditional high load training in contraindicated
2. Adaptations and benefits are greater at 30% 1 RM compared to 20% 1 RM
3. Training durations >6 weeks offer greater returns in strength adaptions
4. BFR training can be applied to a range of populations who seek to progress strength while reducing loads on associated muscle, connective, tendinous, and bony tissues

Reference

Slysz. J, Stultz, J., Burr, J (2016). The efficacy of blood flow restricted exercise: A systematic review & meta-analysis. Journal of Science and Medicine in Sport. 19: 669-675.

Introduction

Lateral ankle sprains are one of the most common injuries for physically active individuals, occurring when the ankle rolls or gives out during activity. An ankle sprain can involve tearing of some or much of the ligament fibers of the ankle. Chronic Ankle Instability (CAI) happens when the ankle is repeatedly sprained, occurring around 30-40% of the time. One theory behind the prevalence of CAI is the change in balance and position receptors input and output, altering the ankle’s neuromuscular control. This study examined if balance training on the stable ankle would have any effect on the unstable ankle.

Methods

27 individuals between the age 13-35 volunteered for this study; 13 were in the treatment group, and 14 were in the control group. Both groups participated in pre-training and post-training testing, which consisted of an ankle and foot outcome measure, a dynamic balance test of both legs, and a static balance test of both legs.

Treatment

The treatment group participated in a 30-minute physical therapy session twice per week for four weeks. Each individual’s program consisted of the same 8 balance activities, which were modified and progressed in difficulty as appropriate by a Physical Therapist. Activities included: single leg standing on different surfaces, single leg hopping in different directions, tossing and catching a ball while on one leg, and hip hikes. The individuals were training their stable ankle only; if their left ankle had CAI, all of these activities were performed on their right ankle. The control group were instructed to continue their normal activities, and to not work on any ankle or balance specific exercises.

Results and PTF Implications

Following the 4 weeks of balance training on the stable ankle, the rehabilitation group showed statistically significant improvements in all three testing measures compared to the control group, including static and dynamic balance. This study showed that training the stable ankle increased the neuromuscular control of the unstable ankle, which in turn could decrease the risk of future ankle sprains. Here at Physical Therapy First, we will use this information to help an individual who may be experiencing CAI and balance limitations. We can apply the results of this study to improve your balance and stability in your affected ankle using both lower extremities. Our licensed Physical Therapists have the knowledge and expertise to get you safely back on both feet, even if that means training only one foot at a time.

Reference

Hale SA, Fergus A, Axmacher R, Kiser K. Bilateral improvements in lower extremity function after unilateral balance training in individuals with chronic ankle instability. Journal of Athletic Training. Volume 49, Number 2, pages 181-191.

Introduction

For athletes, post-exercise cold therapy is a widely accepted recovery modality to decrease muscle soreness and muscle swelling, and facilitate a speedier recovery. Cold-water immersion (CWI) and partial-body cryotherapy (PBC) are two forms of cold therapy intended to improve muscle recovery in athletes. The authors in the study, Cold-water or partial-body cryotherapy? Comparison of physiological responses and recovery following muscle damage, compare physiological markers including muscle oxygen saturation (SmO2), cutaneous vascular conductance (CVC), mean arterial pressure (MAP), and skin temperature in participants following CWI or PBC to compare the effectiveness of both modalities.

 Materials and Methods

Twenty male participants regularly involved in moderate physical endurance exercise volunteered for the study. The experiment followed a parallel group design and the participants were randomly assigned to either the CWI or PBC group. Both groups performed a muscle-damaging exercise which included five sets of 20 box jumps. Following the exercise, the participants received either CWI or PBC. The CWI involved immersing in cold water (+10 degrees Celsius) up to sternum level for ten minutes. The PBC participants entered a cryocabin  for two and a half minutes (-60 degrees Celsius for 30 seconds and -135 degrees Celsius for two minutes).

Physiological parameters which include SmO2, CVC, MAP, and skin temperature were measured before and immediately following exercise as well as in ten-minute intervals up to 60 minutes post-exercise. Indirect markers of muscle damage including rating of delayed onset of muscle soreness (DOMS), anterior thigh muscle swelling, 2-leg vertical jump performance (VJP), and maximal voluntary contraction (MVC) of the knee extensors, were assessed pre-exercise and 24, 48, and 72 hours post-exercise.

Results

Physiological Parameters

SmO2: There was a greater reduction in SmO2 following CWI compared to PBC at ten minutes and 40     minutes after exposure.

CVC: CWI decreased CVC significantly 10 minutes after the treatment compared to baseline values.

MAP: A significant increase was observed in both groups only directly after the treatments compared to baseline.

Mean Skin Temperature: The mean skin temperature was significantly lower in the PBC group only immediately after the treatment compared to the CWI group. Ten minutes following treatment, the CWI group had significantly lower temperature than the PBC group.

Recovery Parameters

Anterior Muscle Swelling: Compared to baseline, swelling was significantly increased in only the CWI group.

VJP: The CWI group had lower performances at 60 minutes after the treatment compared to baseline values.

MVC: MVC significantly decreased compared to baseline values at 60 minutes post-treatment in both groups. Both groups recovered their MVC within 24 hours.

DOMS: DOMS peaked at 24 hours in the PBC group and after 48 hours in the CWI group compared to baseline. Neither the PBC group nor the CWI group recovered from DOMS 72 hours after the damaging protocol and there was no significant difference for DOMS between groups.

Conclusions

The primary findings of the study are that the physiological impact of CWI was significantly greater than PBC. There was decreased oxygen saturation, decreased vascular conductance, increased arterial pressure, and reduced skin temperature in the CWI group as compared to the PBC group. This restriction of blood flow to the muscle helps to wash out waste products like lactic acid which cause muscle soreness, decrease metabolic activity, and reduce swelling and tissue breakdown.

There was no differences in objective and subjective recovery between CWI and PBC up to 72 hours post-exercise. This is the first study to compare the physiological responses and muscle recovery effects between CWI and PBC. The results suggest that either modality could be used for muscle recovery after exercise. The largest limitation in this study is the lack of a control group. It is important that additional studies include a control group to compare these two interventions to passive recovery.

PT First Implications

Cryotherapy in the form of CWI or PBC could be effective in promoting quicker, less painful muscle recovery after exercise. PT First’s therapists are capable of evaluating and screening athletes for exercise induced injuries and recommending various forms of cryotherapy treatment as an adjunct to skilled physical therapy.

Reference

Hohenauer, E., Costello, J., Stoop, R., Kung, U., Deliens, T., Clijsen, R (2017). Cold‐water or partial‐body cryotherapy? Comparison of physiological responses and recovery following muscle damage. Scandinavian Journal of Medicine &Science in Sports. Volume 28, Issue 3.

In the days following unaccustomed or intense training or competition, athletes often experience dull, aching pain, stiffness, and loss of muscle strength that can last for up to 5-7 days. This phenomenon is termed exercise-induced muscle damage (EIMD). Muscle damage is characterized by a sustained reduction in optimal force production, the delayed onset of muscle soreness (DOMS), and an acute inflammatory response. It has been proposed that cold therapies aid recovery following EIMD through a dampening of the inflammatory response, edema reduction, and through an analgesic effect.

A novel form of cold therapy, Whole Body Cryotherapy (WBC) has gained popularity in athletes as an anti-inflammatory treatment. A typical session of WBC involves standing in a chamber that fills with a safe, but extremely cold gas, maintained at temperatures of -110 degrees Celsius to -190 degrees Celsius (-166 to -220 degrees Fahrenheit) for at least two minutes and a maximum of five minutes. The authors in the study, Whole-body Cryotherapy as a Recovery Technique after Exercise: A Review of the Literature, present an overview of the current research on the topic and provide recommendations for its use by athletes.

Discussion

Four key outcome measures for EIMD utilized in this review include pain, muscle function and performance, inflammatory marker levels, and creatine kinase (CK) levels as a marker of muscle damage.

Pain

The visual analog scale was utilized in the five articles that used pain as an outcome measure. Four studies found a significant decrease in pain by at least 18% when compared to a control at 48 hours post WBC treatment. In one study, there was also decreased pain compared to the control group when performing a body weight squat post-WBC treatment, suggesting WBC treatment may reduce pain during subsequent muscle contractions.

Muscle Function and Performance

Patients received an average of 15 WBC treatment exposures across the six studies that measured muscle function. In one study, a group of tennis players were exposed to WBC every day over a five-day training program. In this study, the WBC group reached fatigue significantly later during a progressively more difficult tennis drill than a control group. The WBC group also experienced a 7.3% increase in stroke effectiveness during a tennis skill game that became progressively more difficult where the control group only increased by 2.6%. In another study, synchronized swimmers were exposed to WBC each day during a period of intensified training and found that a 400 m time trial swim speed was only 0.5% slower after WBC compared to a 1.1% time reduction in the group that did not receive WBC treatment.

Inflammation

The authors who focused on inflammatory marker levels used concentrations of interleukins, tumor necrosis factor (TNF), and C-reactive protein (CRP) to show the amount of inflammation present in the muscle. One study looked at the inflammatory response in runners following a 48-minute simulated trail run. Concentrations of the acute inflammatory marker, CRP, were increased by 515% from baseline in the control group and 123% in a WBC group. The increase of inflammatory interleukin cells that naturally occurs after damaging exercise was limited when participants were exposed to WBC compared to the control.

In another study which observed the effects of WBC prior to exercise, the concentration of the pro-inflammatory interleukin increased more than six times in the control group compared to athletes who were treated with WBC. In addition, interleukin concentration dropped by 11%, indicating that treatment blunted the inflammatory response and possibly reduced muscle damage. Yet another study found WBC increased the concentration of an anti-inflammatory cytokine to twice that of baseline compared to no change relative to baseline in the control group. Further, the interleukin concentrations dropped by 80 % in the WBC group compared to a drop of only 50% in the control subjects . The final study found that a five-day training protocol combined with WBC induced a 60% decrease in the inflammatory cell, TNF-α.

Muscle Damage

Muscle damage focused studies used a measure of CK to determine the amount of breakdown in muscles. One study showed a 30% decline in CK after ten exposures to WBC over a five-day period as compared to a control group. A second study reported that CK concentrations were 34% lower with the inclusion of WBC treatment six days into a training protocol compared to a training protocol without WBC treatment. These results were supported by a separate study that reported daily exposure to WBC over a five-day training program with elite rugby players reduced CK by 40%. Another study found WBC treatment significantly reduced CK in tennis players where concentrations of this muscle enzyme in the control group remained virtually the same after five days of training. A final study found no significant changes in CK relative to a control group with protocols using either three or six exposures to WBC. The results from this study suggest that there may be a dose response to WBC when assessing CK concentration, where a reduction in circulating CK is in proportion to the number of exposures to WBC during the recovery process.

Limitations and Future Research

The lack of ability to blind for recovery treatment in the research makes it impossible to eliminate the potential placebo effect. Further investigation into the effects of multiple WBC exposures during extended periods of athletic training is warranted to determine potential effects on recovery, performance and processes of muscle adaptation. Future studies will require larger sample sizes to determine the significance of immunological changes and stringent methodological control to identify the exact influence of WBC on these pathways.

Conclusion

In conclusion, the studies referenced in this article suggest that WBC may be successful in decreasing pain, inflammation, and muscle damage and increasing muscle function. With WBC treatment groups recording pain scores an average of 31% lower than control groups, evidence tends to favor WBC as an analgesic treatment after damaging exercise. Data from inflammatory markers and CK suggest that WBC may dampen the inflammatory cytokine response which means less tissue damage and a faster recovery. Multiple exposures of three or more sessions of three minutes conducted immediately after and in the two to three days post-exercise have presented the most consistent results. There are contraindications to this modality including hypertension, circulatory disorder, and history of a stroke, to name a few. The athlete or patient needs to be properly screened and perform a thorough healthy history prior to treatment.

PT First Implications

As the research on WBC continues to evolve, this treatment could be a good adjunct to skilled physical therapy during an athlete’s training. Localized cryotherapy is a common modality seen in a physical therapy setting to treat pain and inflammation. WBC provides an avenue to treat more widespread muscle pain in multiple area of the body and could be beneficial for athletes during their training season.

Reference:

Rose, C., Edwards, K., Siegler, J., Graham, K., Caillaud, C (2017). Whole-body Cryotherapy as a Recovery Technique after Exercise: A Review of the Literature. International Journal of Sports Medicine. 38: 1049-1060.

Arnica montana is a plant native to the Siberian mountains and Central Europe. This plant has homeopathic uses to treat symptoms caused by many inflammatory conditions. Evidence suggest that Arnica montana could be an alternative to non-steroidal anti-inflammatory drugs. Arnica montana has been sold as tincture, ointment, cream, and gel. Arnica montana may be more easily recognized under the different names that it has been sold under; leopard’s bane, wolf’s bane, mountain tobacco, and mountain snuff. This plant has been used for pathological conditions, including pain, stiffness, and swelling.

Arnica montana is able to treat some inflammatory conditions as it contains a high concentration of sesquiterpenes which is responsible for anti-inflammatory activity. In vitro studies have shown that the most active components in Arnica is helenalin, which is a type of sesquiterpene lactone that has anti-inflammatory properties. This article reviews several uses of Arnica which include acute ankle sprains, post-surgical pain, muscle soreness after exercise, and osteoarthritis. Arnica’s affect on muscle soreness post-exercise was measured in a study involving 82 marathon runners. The study showed that 5 pills of Arnica 30D, given 2 times a day from the evening before until 3 days after the marathon improved muscle soreness in marathon runners immediately after the competition, however it did not protect from cell damage. Another study involving 204 patients with osteoarthritis of the interphalangeal joints of the hands showed that topical application of a 4-cm gel strip of Arnica (50 g tincture/100 g) 3 times a day showed similar effectiveness as ibuprofen in reducing pain, functional hand capacity, number of painful joints in both hands and intensity of morning stiffness in the worst affected hand.

As mentioned before, Arnica can be administered in a variety of forms such as orally or topically. When applied topically, studies show that Arnica may be an alternative to ibuprofen due to the high levels of sesquiterpenes. The amount of sesquiterpene is dependent on which portion of the plant used. Due to various parts of the Arnica plant that can be extracted, the clinical effectiveness will vary. The safe use of Arnica is guaranteed by the European Pharmacopoeia and by specific Arnica monographs which provide guidelines for pharmaceutical companies to abide by. The article concluded that Arnica is a potential therapeutic alternative to non-steroidal anti-inflammatory drugs, especially for patients undergoing pharmacological polytherapy. Further research with larger cohorts of patients are needed to support the effect of Arnica on various inflammatory conditions.

Physical Therapy First Recommendation:

For patients seeking a homeopathic treatment for symptoms from inflammatory conditions, discuss with your physician the appropriateness of Arnica montana.

Reference:

Iannitti, T., Morales-Medina, J., Bellavite, P., Rottigni, V., Palmieri, B. 2016. Effectiveness and Safety of Arnica montana in Post-Surgical Setting, Pain and Inflammation, The American Journal of Therapeutics, 23, e184-e197.