Acute effects of stretching on muscle stiffness after a bout of exhaustive eccentric exercise

Oxidative stress involves phenotype modulation of morbid soreness symptoms in fibromyalgia

OBJECTIVES

Muscle soreness occurs after exercise and also in musculoskeletal diseases, such as fibromyalgia (FM). However, the nosography and pathoetiology of morbid soreness in FM remain unknown. This study aimed to investigate the morbid soreness of FM, evaluate its therapeutic responses and probe its pathophysiology with metabolomics profiling.

METHODS

Patients with newly diagnosed FM were prospectively recruited and completed self-report questionnaires pertaining to musculoskeletal symptoms. The phenotypes and metabotypes were assessed with variance, classification and correlation analyses.

RESULTS

Fifty-one patients and 41 healthy controls were included. Soreness symptoms were prevalent in FM individuals (92.2%). In terms of manifestations and metabolomic features, phenotypes diverged between patients with mixed pain and soreness symptoms (FM-PS) and those with pain dominant symptoms. Conventional treatment for FM did not ameliorate soreness severity despite its efficacy on pain. Moreover, despite the salient therapeutic efficacy on pain relief in FM-PS cases, conventional treatment did not improve their general disease severity. Metabolomics analyses suggested oxidative metabolism dysregulation in FM, and high malondialdehyde level indicated excessive oxidative stress in FM individuals as compared with controls (p=0.009). Contrary to exercise-induced soreness, lactate levels were significantly lower in FM individuals than controls, especially in FM-PS. Moreover, FM-PS cases exclusively featured increased malondialdehyde level (p=0.008) and a correlative trend between malondialdehyde expression and soreness intensity (r=0.337, p=0.086).

CONCLUSIONS

Morbid soreness symptoms were prevalent in FM, with the presentation and therapeutic responses different from FM pain conditions. Oxidative stress rather than lactate accumulation involved phenotype modulation of the morbid soreness in FM.

TRIAL REGISTRATION NUMBER

NCT04832100.

Short- and Intermediate-Term Results of Extracorporeal Shockwave Therapy for Noninsertional Achilles Tendinopathy

BACKGROUND

Earlier randomized controlled trials (RCTs) reported only midterm (3-4 months) results of extracorporeal shockwave therapy (ESWT) as a treatment for noninsertional Achilles tendinopathy (NAT). This study compared the effectiveness of an eccentric loading program followed by stretching exercises combined with ESWT (study group) or sham ESWT (control group) for treating chronic NAT in both the short and long term.

METHODS

This double-blind RCT was conducted between 2018 and 2020. Adult patients with unilateral NAT who failed standard conservative treatment were randomly allocated to either group. Function and pain were assessed at baseline, 1 month, and 16 months using the Victorian Institute of Sport Assessment-Achilles questionnaire (VISA-A) and visual analog scale (VAS), respectively. Mixed-design analysis of variance and nonparametric statistics were performed. Twenty-two men and 28 women aged 18 to 40 years were allocated into 2 equally matched groups.

RESULTS

Function and pain scores in the study group were not significantly different from control group scores at baseline (VISA-A: 22.2 ± 6.5 vs 21.0 ± 5.2 and VAS: 8 ± 1 vs 8 ± 1, respectively). Both groups significantly improved posttreatment (VISA-A: 85 ± 6.2 vs 53.4 ± 7.7 and VAS: 1 ± 2 vs 7 ± 2, respectively). At the 16-month follow-up, outcome scores declined slightly but significantly in the study group (VISA-A: 80 ± 5.3; VAS: 3 ± 2) and improved in the control group (VISA-A: 67 ± 5.6; VAS: 5 ± 1). However, both groups were significantly better than baseline. At both time points, the study group had significantly superior scores (statistically and clinically) than the control group (P = .0001).

CONCLUSION

Combining calf eccentric loading with stretching exercises resulted in significant improvements in the pain and functional scores in patients with NAT. Adding ESWT to this combined protocol resulted in significantly greater improvements in both the short and long term.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Effects of reactive oxygen species and interplay of antioxidants during physical exercise in skeletal muscles

A large number of researches have led to a substantial growth of knowledge about exercise and oxidative stress. Initial investigations reported that physical exercise generates free radical-mediated damages to cells; however, in recent years, studies have shown that regular exercise can upregulate endogenous antioxidants and reduce oxidative damage. Yet, strenuous exercise perturbs the antioxidant system by increasing the reactive oxygen species (ROS) content. These alterations in the cellular environment seem to occur in an exercise type-dependent manner. The source of ROS generation during exercise is debatable, but now it is well established that both contracting and relaxing skeletal muscles generate reactive oxygen species and reactive nitrogen species. In particular, exercises of higher intensity and longer duration can cause oxidative damage to lipids, proteins, and nucleotides in myocytes. In this review, we summarize the ROS effects and interplay of antioxidants in skeletal muscle during physical exercise. Additionally, we discuss how ROS-mediated signaling influences physical exercise in antioxidant system.

The Efficacy of Dynamic Contract-Relax Stretching on Delayed-Onset Muscle Soreness Among Healthy Individuals: A Randomized Clinical Trial

OBJECTIVE

To evaluate the efficacy of dynamic contract-relax stretching on delayed-onset muscle soreness (DOMS) in the calf muscle of healthy individuals.

DESIGN

Randomized clinical trial.

SETTING

Research laboratory.

PARTICIPANTS

Three groups of 16 healthy participants (n = 48) were recruited by convenience sampling.

INTERVENTIONS

Three sets of resisted bilateral heel-raising exercises until exhaustion were conducted to initiate DOMS. Participants were randomly allocated into control group without any interventions, dynamic contract-relax stretching (DS), or static stretching (SS) groups. Dynamic contract-relax stretching and SS groups performed DS and SS, respectively, on the dominant leg twice a day for 5 consecutive days (before time points of outcome measurements at 24, 48, 72, 96, and 120 hours postexercise, respectively).

MAIN OUTCOME MEASURES

Muscle soreness, lower leg girth, pressure pain threshold (PPT), range of motion (ROM), and muscle strength were measured before exercise, immediately after, and at 24, 48, 72, 96, and 120 hours postexercise.

RESULTS

There was a significant effect of time in all outcome measures including muscle soreness, lower leg girth, PPT, ROM, and muscle strength; however, there were no significant group differences or group by time interactions.

CONCLUSIONS

The effect of DS on relieving DOMS in the calf muscle is insignificant in this study. Further evidence is needed to prove the efficacy of DS on DOMS.

CLINICAL RELEVANCE

Stretching is commonly recommended before and after exercise; however, this study showed no significant impact of DS or SS in treating DOMS.

MR elastography measurement of the effect of passive warmup prior to eccentric exercise on thigh muscle mechanical properties

Purpose

To investigate the effect of warmup by application of the thermal agent Deep Heat (DH) on muscle mechanical properties using magnetic resonance elastography (MRE) at 3T before and after exercise‐induced muscle damage (EIMD).

Materials and Methods

Twenty male participants performed an individualized protocol designed to induce EIMD in the quadriceps. DH was applied to the thigh in 50% of the participants before exercise. MRE, T₂‐weighted MRI, maximal voluntary contraction (MVC), creatine kinase (CK) concentration, and muscle soreness were measured before and after the protocol to assess EIMD effects. Five participants were excluded: four having not experienced EIMD and one due to incidental findings.

Results

Total workload performed during the EIMD protocol was greater in the DH group than the control group (P < 0.03), despite no significant differences in baseline MVC (P = 0.23). Shear stiffness |G*| increased in the rectus femoris (RF) muscle in both groups (P < 0.03); however, DH was not a significant between‐group factor (P =  0.15). MVC values returned to baseline faster in the DH group (5 days) than the control group (7 days). Participants who displayed hyperintensity on T₂‐weighted images had a greater stiffness increase following damage than those without: RF; 0.61 kPa vs. 0.15 kPa, P < 0.006, vastus intermedius; 0.34 kPa vs. 0.03 kPa, P = 0.06.

Conclusion

EIMD produces increased muscle stiffness as measured by MRE, with the change in |G*| significantly increased when T₂ hyperintensity was present. DH did not affect CK concentration or soreness; however, DH participants produced greater workload during the EIMD protocol and exhibited accelerated MVC recovery.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2017;46:1115–1127.

The Acute Effects of Static Stretching on Speed and Agility Performance Depend on Stretch Duration and Conditioning Level

Avloniti, A, Chatzinikolaou, A, Fatouros, IG, Avloniti, C, Protopapa, M, Draganidis, D, Stampoulis, T, Leontsini, D, Mavropalias, G, Gounelas, G, and Kambas, A. The acute effects of static stretching on speed and agility performance depend on stretch duration and conditioning level. J Strength Cond Res 30(10): 2767-2773, 2016-Although static stretching (SS) is an integral part of physical preparation before training and competition, its usefulness in regards to power performance improvement has been questioned. The aim of this study was to investigate the effect of 6 SS durations on speed and agility performance. According to a cross-over design, 34 trained men (age, 20.5 ± 1.4 years; height, 1.81 ± 0.2 m; weight, 77.2 ± 2.6 kg; body fat, 8.2 ± 2.6%) participated in a control session (no stretch) and 6 experimental conditions (10, 15, 20, 30, 40, and 60 seconds) performed in a randomized order. Performance in speed (10 and 20 m) and agility (T-test) was measured after the control and experimental conditions. Static stretching, consisting of stretches for hip extensors, hip adductors, knee extensors, knee flexors, and ankle sole flexors, was performed after light cardiovascular exercise (8 minutes). A 1-way repeated-measures analysis of variance showed that speed was improved only by SS of short duration (15/20 seconds), whereas agility remained unaffected by all SS trials. When participants' speed and agility level was taken into account, it was revealed that only those of moderate performance demonstrated an improved speed (in 15- and 20-second trials) and agility (in 10- and 15-second trials) performance. These results suggest that short-duration SS protocols induce an acute improvement of speed and agility performance, whereas longer-duration SS protocols have neither positive nor negative effect. Furthermore, it seems that individuals of lower speed and agility performance level are more likely to benefit by a short-duration SS protocol.

Glenohumeral range of motion (ROM) and isometric strength of professional team handball athletes, part III: changes over the playing season

INTRODUCTION

The aim of our study was to investigate the relation of workload on range of motion and isometric strength of team handball athletes' shoulders over a competitive season.

MATERIALS AND METHODS

31 Professional male handball athletes underwent clinical shoulder examinations. Athletes were examined subsequently during the complete playing season (week 0, 6, 22 and 40) to determine bilateral isometric shoulder rotational strength and active range of motion (ROM). In addition, relative (intraclass correlation coefficients (ICC) and absolute (standard error of measurement) reliability were calculated.

RESULTS

Intraobserver reliability was excellent (ICC 0.76-0.98) for isometric strength and flexibility measurements. Internal rotation (IR) and total arc ROM in the throwing shoulder (TS) decreased significantly (p < 0.05) in both sequences (week 22 to week 40, week 0 to week 40). External rotation (ER) ROM and isometric strength in IR and ER did not change significantly. Glenohumeral internal rotation deficit (GIRD) and external rotation gain (ERG) of the TS decreased significantly between week 22 and week 40, but both did not change overall (week 0 to week 40). There was significant influence on IR ROM (week 22 to week 40) and strength in ER (week 0 to week 40) in the non-throwing shoulder.

CONCLUSIONS

Several characteristics of handball players' shoulders changed significantly from the beginning to the end of a season. More specifically, the repetitive forces accumulated during the competitive season resulted in altered GIRD, ERG and isometric strength of the dominant glenohumeral joint.

The relevance of stretch intensity and position-a systematic review

Stretching exercises to increase the range of motion (ROM) of joints have been used by sports coaches and medical professionals for improving performance and rehabilitation. The ability of connective and muscular tissues to change their architecture in response to stretching is important for their proper function, repair, and performance. Given the dearth of relevant data in the literature, this review examined two key elements of stretching: stretch intensity and stretch position; and their significance to ROM, delayed onset muscle soreness (DOMS), and inflammation in different populations. A search of three databases, Pub-Med, Google Scholar, and Cochrane Reviews, identified 152 articles, which were subsequently categorized into four groups: athletes (24), clinical (29), elderly (12), and general population (87). The use of different populations facilitated a wider examination of the stretching components and their effects. All 152 articles incorporated information regarding duration, frequency and stretch position, whereas only 79 referred to the intensity of stretching and 22 of these 79 studies were deemed high quality. It appears that the intensity of stretching is relatively under-researched, and the importance of body position and its influence on stretch intensity, is largely unknown. In conclusion, this review has highlighted areas for future research, including stretch intensity and position and their effect on musculo-tendinous tissue, in relation to the sensation of pain, delayed onset muscle soreness, inflammation, as well as muscle health and performance.

Effects of phonophoresis and gold nanoparticles in experimental model of muscle overuse: role of oxidative stress

The aim of the study described here was to investigate the effects of pulsed ultrasound and gold nanoparticles (AuNPs) on behavioral, inflammatory and oxidative stress parameters in an experimental model of overuse. Wistar rats performed 21 d of exercise on a treadmill at different intensities and were exposed to ultrasound in the presence or absence of AuNPs. The overuse model promoted behavioral changes and increased creatine kinase, superoxide dismutase and glutathione peroxidase activity, as well as the levels of superoxide, nitrotyrosine, nitric oxide, thiobarbituric acid reactive substance, carbonyl, tumor necrosis factor α and interleukin-6. These values were significantly decreased by AuNPs and by AuNPs plus ultrasound. Catalase activity remained unchanged and the glutathione level increased significantly after exposure to AuNPs plus ultrasound. These results suggest a susceptibility to anxiety as well as elevated levels of oxidative stress. However, therapeutic interventions with AuNPs plus ultrasound reduced the production of oxidants and oxidative damage and improved the anti-oxidant defense system.

Changes in force and stiffness after static stretching of eccentrically-damaged hamstrings

PURPOSE

This study compared responses to static stretching between eccentrically damaged and non-damaged muscles.

METHODS

Twelve young men performed 60 maximum knee flexor eccentric contractions of one leg, and received a 300-s continuous passive static stretching at tolerable intensity without pain to both knee flexors at 2 and 4 days after the eccentric exercise. Range of motion (ROM) and passive stiffness during knee extension, passive torque at onset of pain (PT), maximum voluntary isometric (MVC-ISO) and isokinetic concentric contraction torque (MVC-CON), and visual analogue scale (VAS) for muscle soreness were measured before, immediately after, 60 min, 2 and 4 days after exercise as well as before, immediately after, 20 and 60 min after the stretching. Changes in these variables after eccentric exercise and stretching were compared between limbs.

RESULTS

The eccentric exercise decreased MVC-ISO, MVC-CON, ROM and PT, and increased passive stiffness and VAS (p < 0.05), suggesting that muscle damage was induced to the knee flexors. ROM and PT increased after stretching for both limbs; however, the magnitude of the increase was greater (p < 0.05) for the damaged than non-damaged limb. Passive stiffness decreased for both limbs similarly (4-7 %) at immediately after stretching (p < 0.05). Significant decreases in MVC-ISO torque (7-11 %) after stretching were observed only for the non-damaged limb (p < 0.05), but MVC-CON torque did not change after stretching for both limbs. VAS decreased for the exercised limb after stretching (p < 0.05).

CONCLUSIONS

These results suggest that the static stretching at tolerable intensity without pain produced greater positive effects on damaged than non-damaged muscles.

An Acute Bout of Quadriceps Muscle Stretching has no Influence on Knee Joint Proprioception

The main objective of this study was to determine if an acute bout of static stretching of the quadriceps muscle affects the sense of joint position, the threshold to detect passive movement, and the sense of force. Thirty young, healthy men (age : 22.1 ± 2.7 years) were randomly divided into two groups. The Stretching Group (n=15) underwent stretching of the dominant quadriceps muscle, which comprised ten passive stretches lasting 30 seconds each, while the Control Group (n=15) remained seated for the same length of time. A repeated-measures analysis of variance was used to establish intragroup differences over time, and an independent sample t-test was used to compare the dependent variables between groups at each moment. None of the measurements revealed any significant change between both groups in each assessment moment or between moments within groups (p>0.05). This study demonstrated that static quadriceps muscle stretching has no effect on the sense of knee joint position, threshold to detect passive movement, and force sense, suggesting that stretching does not have appreciable effect on the spindle firing characteristics and tendon organs activation.

Evidence of the physiotherapeutic interventions used currently after exercise-induced muscle damage: systematic review and meta-analysis

INTRODUCTION

Exhaustive and/or unaccustomed exercise, mainly involving eccentric muscle actions, induces temporary muscle damage, evidenced by delayed onset muscle soreness (DOMS) and decreased muscle function. Different strategies to recover from its signs and symptoms have been studied and, as a result, a significant number of articles on this issue have been published.

OBJECTIVE

To assess whether some modalities currently used in physiotherapy such as massage, cryotherapy, stretching and low-intensity exercise are effective for treating the signs and symptoms of exercise-induced muscle damage.

METHODS

Randomized controlled trials (RCTs), written in English or Portuguese, that included physiotherapeutic interventions [i.e., massage, cryotherapy, stretching and low-intensity exercise, on adult human subjects (18-60 years old) of both gender] were searched on electronic databases including MEDLINE, CINHAL, EMBASE, PEDro and SPORTDiscus.

MAIN OUTCOME MEASURES

"Muscle soreness" and "muscle strength" were the outcome measures included in the meta-analysis.

RESULTS

Thirty-five studies were included; nine analysed the effects of massage, 10 examined the effects of cryotherapy, nine investigated the effects of stretching and seven focused on low-intensity exercise intervention. Massage was the only intervention with positive effects, reducing soreness at 24 h, on average, 0.33 on 10 cm visual analog scale (95 percent CI: -0.59, -0.07) and increasing muscle recovery by 1.87 percent (95 percent CI: 0.30, 3.44). Additionally, there is inconclusive evidence to support the use of cryotherapy, while there is little evidence to prove the efficacy of stretching and low-intensity exercise.

CONCLUSION

Massage proved slightly effective in the relief of symptoms and signs of exercise-induced muscle damage. Therefore, its mean effect was too small to be of clinical relevance. There is a lack of evidence to support the use of cryotherapy, stretching and low-intensity exercise.

A review of the acute effects of static and dynamic stretching on performance

An objective of a warm-up prior to an athletic event is to optimize performance. Warm-ups are typically composed of a submaximal aerobic activity, stretching and a sport-specific activity. The stretching portion traditionally incorporated static stretching. However, there are a myriad of studies demonstrating static stretch-induced performance impairments. More recently, there are a substantial number of articles with no detrimental effects associated with prior static stretching. The lack of impairment may be related to a number of factors. These include static stretching that is of short duration (<90 s total) with a stretch intensity less than the point of discomfort. Other factors include the type of performance test measured and implemented on an elite athletic or trained middle aged population. Static stretching may actually provide benefits in some cases such as slower velocity eccentric contractions, and contractions of a more prolonged duration or stretch-shortening cycle. Dynamic stretching has been shown to either have no effect or may augment subsequent performance, especially if the duration of the dynamic stretching is prolonged. Static stretching used in a separate training session can provide health related range of motion benefits. Generally, a warm-up to minimize impairments and enhance performance should be composed of a submaximal intensity aerobic activity followed by large amplitude dynamic stretching and then completed with sport-specific dynamic activities. Sports that necessitate a high degree of static flexibility should use short duration static stretches with lower intensity stretches in a trained population to minimize the possibilities of impairments.

Changes in shoulder and elbow passive range of motion after pitching in professional baseball players

BACKGROUND

The overhead throwing athlete has unique range of motion characteristics of the shoulder and elbow. Numerous theories exist to explain these characteristics; however, the precise cause is not known. Although it is accepted that range of motion is altered, the acute effect of baseball pitching on shoulder and elbow range of motion has not been established.

HYPOTHESIS

There will be a reduction in passive range of motion immediately after baseball pitching.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixty-seven asymptomatic male professional baseball pitchers participated in the study. Passive range of motion measurements were recorded using a customized bubble goniometer for shoulder external rotation, shoulder internal rotation, total shoulder rotational motion, elbow flexion, and elbow extension on the dominant and nondominant arms. Testing was performed on the first day of spring training. Measurements were taken before, immediately after, and 24 hours after pitching.

RESULTS

A significant decrease in shoulder internal rotation (-9.5 degrees), total motion (-10.7 degrees), and elbow extension (-3.2 degrees) occurred immediately after baseball pitching in the dominant shoulder (P<.001). These changes continued to exist 24 hours after pitching. No differences were noted on the nondominant side.

CONCLUSION

Passive range of motion is significantly decreased immediately after baseball pitching. This decrease in range of motion continues to be present 24 hours after throwing. High levels of eccentric muscle activity have previously been observed in the shoulder external rotators and elbow flexors during pitching. These eccentric muscle contractions may contribute to acute musculotendinous adaptations and altered range of motion. The results of this study may suggest a newly defined mechanism to range of motion adaptations in the overhead throwing athlete resulting from acute musculoskeletal adaptations, in addition to potential osseous and capsular adaptations.