Effect of Compression Garments on the Development of Delayed-Onset Muscle Soreness: A Multimodal Approach Using Contrast-Enhanced Ultrasound and Acoustic Radiation Force Impulse Elastography

Imaging of muscle injuries in soccer

Accurate diagnosis of muscle injuries is a challenge in everyday clinical practice and may have profound impact on the recovery and return-to-play decisions of professional athletes particularly in soccer. Imaging techniques such as ultrasound and magnetic resonance imaging (MRI), in addition to the medical history and clinical examination, make a significant contribution to the timely structural assessment of muscle injuries. The severity of a muscle injury determined by imaging findings has a decisive influence on therapy planning and affects prognosis. Imaging is of high importance when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be needed. This narrative review will discuss ultrasound and MRI for the assessment of sports-related muscle injuries in the context of soccer, including advanced imaging techniques, with the focus on the clinical relevance of imaging findings for the prediction of return to play.

Comparison of In Vivo Stiffness of Tendons Commonly Used for Anterior Cruciate Ligament Reconstruction - A Shear Wave Elastography Study

RATIONALE AND OBJECTIVES

There are currently no studies investigating the in vivo stiffness of the most commonly used autografts for anterior cruciate ligament reconstruction (ACLR) using Shear wave elastography (SWE). We hypothesize that there are differences regarding the elastic properties between the three tendons commonly used for ACLR and that they are influenced by patient-related factors.

MATERIALS AND METHODS

80 healthy subjects (25 females, 55 males, age: 25.33 ± 4.76 years, BMI: 23.76 ± 3.14 kg/m2, 40 semiprofessional athletes, athlete group [AG], age: 25.51 [19-29]; 40 healthy controls, control group [CG], age: 25.50 [20-29]) were recruited as participants. In addition to patient reported outcome scores, every participant underwent a standardized multimodal ultrasound protocol consisting of B-mode-ultrasound (B-US), Color Doppler-ultrasound (CD-US) and a SWE examination of the bilateral quadriceps tendon (QT), patellar tendon (PT) and semitendinosus tendon (ST).

RESULTS

The highest shear wave velocity (SWV) were observed in ST (4.88 (4.35-5.52) m/s, ST vs QT, p = 0.005; ST vs PT, p < 0.001) followed by QT (4.61 (4.13-5.26) m/s, QT vs PT, p < 0.001) and PT (3.73 (3.30-4.68) m/s). Median QT, PT and ST stiffness was significantly higher in AG compared to CG. Male subjects tend to have stiffer QT and PT than female subjects. Positive correlation with SWV was obtained for age and activity level.

CONCLUSION

There are significant differences regarding in vivo tendon stiffness between the most frequently used autograft tendon options for ACLR. The quantitative information obtained by SWE could be of particular interest for graft choice for ACLR.

Early functional and morphological changes of calf muscles in delayed onset muscle soreness (DOMS) assessed with 7T MRI

BACKGROUND

To assess morphological and functional alterations of the skeletal muscle in exercise-induced delayed onset muscle soreness (DOMS) using 7 Tesla (T) magnetic resonance imaging (MRI).

METHODS

DOMS was induced in 16 volunteers performing an eccentric exercise protocol of the calf muscles of one randomized leg. 7 T MRI including T1w- (0.18×0.18×1mm3), T2w-images (0.2×0.2×2mm3), T2-maps (0.5×0.5×5mm3), and susceptibility weighted imaging (SWI, 0.7×0.7×0.7 mm3) were acquired at baseline, directly (t1) and 60 hours (t2) after the exercise. T2 signal intensity (SI), T2 values [ms], T1 SI and SWI were assessed in the medial (MG) and lateral gastrocnemius muscle (LG) and in the soleus muscle (SM). In addition, the serum creatine kinase (CK) activity, range of motion (ROM) of the ankle, calf circumference, and muscle soreness were assessed at each time point.

RESULTS

Directly after exercise (t1), T2 SI (p=0.04) and T2 values (p=0.03) increased significantly in the LG. No changes of SI and T2 values for MG and SM were present at t1. At t2, T2 SI and T2 values of LG (p=0.001, p=0.02) and MG (p=0.04, p=0.03) increased significantly compared to baseline. T1 SI did not change in any muscle at any time point. In SWI, no signs of intramuscular signal drop could be detected. Clinical parameters confirmed the induction of DOMS, with a significant increase of CK (p=0.03), muscle soreness (p<0.001), calf circumference (p=0.001), and respective a decrease of ROM (p=0.04).

CONCLUSIONS

7 T MRI has the potential to visualize microstructural muscle damage immediately after an exercise that induces DOMS. No changes in susceptibility which could, for example, reflect micro-hemorrhage, could be detected with SWI immediately after exercise or in DOMS. Ultra-high field MRI may potentially be used in sports medicine to monitor intramuscular structural changes, allowing for modification of training intensity or to implement appropriate therapeutic strategies.

Emerging Quantitative Imaging Techniques in Sports Medicine

This article describes recent advances in quantitative imaging of musculoskeletal extremity sports injuries, citing the existing literature evidence and what additional evidence is needed to make such techniques applicable to clinical practice. Compositional and functional MRI techniques including T2 mapping, diffusion tensor imaging, and sodium imaging as well as contrast-enhanced US have been applied to quantify pathophysiologic processes and biochemical compositions of muscles, tendons, ligaments, and cartilage. Dual-energy and/or spectral CT has shown potential, particularly for the evaluation of osseous and ligamentous injury (eg, creation of quantitative bone marrow edema maps), which is not possible with standard single-energy CT. Recent advances in US technology such as shear-wave elastography or US tissue characterization as well as MR elastography enable the quantification of mechanical, elastic, and physical properties of tissues in muscle and tendon injuries. The future role of novel imaging techniques such as photon-counting CT remains to be established. Eventual prediction of return to play (ie, the time needed for the injury to heal sufficiently so that the athlete can get back to playing their sport) and estimation of risk of repeat injury is desirable to help guide sports physicians in the treatment of their patients. Additional values of quantitative analyses, as opposed to routine qualitative analyses, still must be established using prospective longitudinal studies with larger sample sizes.

Measuring Shear Wave Velocity in Adult Skeletal Muscle with Ultrasound 2-D Shear Wave Elastography: A Scoping Review

Ultrasound 2-D shear wave elastography (US 2D-SWE) is a non-invasive, cost-effective tool for quantifying tissue stiffness. Amidst growing interest in US 2D-SWE for musculoskeletal research, it has been recommended that shear wave velocity (SWV) should be reported instead of elastic moduli to avoid introducing unwanted error into the data. This scoping review examined the evolving use of US 2D-SWE to measure SWV in skeletal muscle and identified strengths and weaknesses to guide future research. We searched electronic databases and key review reference lists to identify articles published between January 2000 and May 2021. Two reviewers assessed the eligibility of records during title/abstract and full-text screening, and one reviewer extracted and coded the data. Sixty-six studies met the eligibility criteria, of which 58 were published in 2017 or later. We found a striking lack of consensus regarding the effects of age and sex on skeletal muscle SWV, and widely variable reliability values. Substantial differences in methodology between studies suggest a pressing need for developing standardized, validated scanning protocols. This scoping review illustrates the breadth of application for US 2D-SWE in musculoskeletal research, and the data synthesis exposed several notable inconsistencies and gaps in current literature that warrant consideration in future studies.

MRI of Potassium and Sodium Enables Comprehensive Analysis of Ion Perturbations in Skeletal Muscle Tissue After Eccentric Exercise

OBJECTIVES

The aims were to investigate if potassium ( 39 K) magnetic resonance imaging (MRI) can be used to analyze changes in the apparent tissue potassium concentration (aTPC) in calf muscle tissue after eccentric exercise and in delayed-onset muscle soreness, and to compare these to corresponding changes in the apparent tissue sodium concentration (aTSC) measured with sodium ( 23 Na) MRI.

MATERIALS AND METHODS

Fourteen healthy subjects (7 female, 7 male; 25.0 ± 2.8 years) underwent 39 K and 23 Na MRI at a 7 T MR system, as well as 1 H MRI at a 3 T MR system. Magnetic resonance imaging data and blood samples were collected at baseline (t0), directly after performing eccentric exercise (t1) and 48 hours after exercise (t2). Self-reported muscle soreness was evaluated using a 10-cm visual analog scale for pain (0, no pain; 10, worst pain) at t0, t1, and t2. Quantification of aTPC/aTSC was performed after correcting the measured 39 K/ 23 Na signal intensities for partial volume and relaxation effects using 5 external reference phantoms. Edema volume and 1 H T 2 relaxation times were determined based on the 1 H MRI data. Participants were divided according to their increase in creatine kinase (CK) level into high (CK t2 ≥ 10·CK t0 ) and low CK (CK t2 < 10·CK t0 ) subjects.

RESULTS

Blood serum CK and edema volume were significantly increased 48 hours after exercise compared with baseline ( P < 0.001). Six participants showed a high increase in blood serum CK level at t2 relative to baseline, whereas 8 participants had only a low to moderate increase in blood serum CK. All participants reported increased muscle soreness both at rest and when climbing stairs at t1 (0.4 ± 0.7; 1.4 ± 1.2) and t2 (1.6 ± 1.4; 4.8 ± 1.9) compared with baseline (0 ± 0; 0 ± 0). Moreover, aTSC was increased at t1 in exercised muscles of all participants (increase by 57% ± 24% in high CK, 73% ± 33% in low CK subjects). Forty-eight hours after training, subjects with high increase in blood serum CK still showed highly increased aTSC (increase by 79% ± 57% compared with t0). In contrast, aTPC at t2 was elevated in exercised muscles of low CK subjects (increase by 19% ± 11% compared with t0), in which aTSC had returned to baseline or below. Overall, aTSC and aTPC showed inverse evolution, with changes in aTSC being approximately twice as high as in aTPC.

CONCLUSIONS

Our results showed that 39 K MRI is able to detect changes in muscular potassium concentrations caused by eccentric exercise. In combination with 23 Na MRI, this enables a more holistic analysis of tissue ion concentration changes.

Update of Contrast-enhanced Ultrasound in Musculoskeletal Medicine: Clinical Perspectives - A Review

Contrast-enhanced ultrasound (CEUS) uses an intravascular contrast agent to enhance blood flow signals and assess microcirculation in different parts of the human body. Over the past decade, CEUS has become more widely applied in musculoskeletal (MSK) medicine, and the current review aims to systematically summarize current research on the application of CEUS in the MSK field, focusing on 67 articles published between January 2001 and June 2021 in online databases including PubMed, Scopus, and Embase. CEUS has been widely used for the clinical assessment of muscle microcirculation, tendinopathy, fracture nonunions, sports-related injuries, arthritis, peripheral nerves, and tumors, and can serve as an objective and quantitative evaluation tool for prognosis and outcome prediction. Optimal CEUS parameters and diagnostic cut off values for each disease category remain to be confirmed.

[Imaging of muscle injuries in sports medicine]

BACKGROUND

Early diagnosis of muscle injuries is indispensable in order to initiate appropriate treatment and to facilitate optimal healing.

PURPOSE

The aim of this review is to provide an update on imaging of muscle injuries in sports medicine with a focus on ultrasound and magnetic resonance imaging (MRI) and to present experimental approaches in addition to routine diagnostic procedures.

MATERIALS AND METHODS

A PubMed literature search for the years 2012-2022 using the following keywords was performed: muscle, muscle injury, muscle imaging, muscle injury classification, delayed onset muscle soreness, ultrasound, MRI, sodium MRI, potassium MRI, ultra-high-field MRI, injuries of athletes.

RESULTS

Imaging is crucial to confirm and assess the extent of sports-related muscle injuries and may help establishing treatment decisions, which directly affect the prognosis. This is of importance when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be necessary. In addition to established methods such as B‑mode ultrasound and ¹H‑MRI, individual studies show promising approaches to further improve the imaging of muscle injuries in the future. Prior to the integration of contrast-enhanced ultrasound and X‑nuclei into clinical routine, additional studies are needed to validate these techniques further.

CONCLUSION

B‑mode ultrasound represents an easily available, cost-effective modality for the initial diagnosis of muscle injuries. MRI is still considered the reference standard and enables an accurate morphological assessment of the extent of the injury. There are still no imaging approaches available for the objective determination of the optimal point of return to play.

Sodium and quantitative hydrogen parameter changes in muscle tissue after eccentric exercise and in delayed-onset muscle soreness assessed with magnetic resonance imaging

The objective of the current study was to assess sodium (²³ Na) and quantitative proton (¹ H) parameter changes in muscle tissue with magnetic resonance imaging (MRI) after eccentric exercise and in delayed-onset muscle soreness (DOMS). Fourteen participants (mean age: 25 ± 4 years) underwent ²³ Na/¹ H MRI of the calf muscle on a 3-T MRI system before exercise (t0), directly after eccentric exercise (t1), and 48 h postintervention (t2). In addition to tissue sodium concentration (TSC), intracellular-weighted sodium (ICwS) signal was acquired using a three-dimensional density-adapted radial projection readout with an additional inversion recovery preparation module. Phantoms containing saline solution served as references to quantify sodium concentrations. The ¹ H MRI protocol consisted of a T₁ -weighted turbo spin echo sequence, a T₂ -weighted turbo inversion recovery, as well as water T₂ mapping and water T₁ mapping. Additionally, blood serum creatine kinase (CK) levels were assessed at baseline and 48 h after exercise. The TSC and ICwS of exercised muscles increased significantly from t0 to t1 and decreased significantly from t1 to t2. In the soleus muscle (SM), ICwS decreased below baseline values at t2. In the tibialis anterior muscle (TA), TSC and ICwS remained at baseline levels at each measurement point. However, high-CK participants (i.e., participants with a more than 10-fold CK increase, n = 3) displayed different behavior, with 2- to 4-fold increases in TSC values in the medial gastrocnemius muscle (MGM) at t2. ¹ H water T₁ relaxation times increased significantly after 48 h in the MGM and SM. ¹ H water T₂ relaxation times and muscle volume increased in the MGM at t2. Sodium MRI parameters and water relaxation times peaked at different points. Whereas water relaxation times were highest at t2, sodium MRI parameters had already returned to baseline values (or even below baseline values, for low-CK participants) by this point. The observed changes in ion concentrations and water relaxation time parameters could enable a better understanding of the physiological processes during DOMS and muscle regeneration. In the future, this might help to optimize training and to reduce associated sports injuries.

Using Shear-Wave Elastography to Assess Exercise-Induced Muscle Damage: A Review

Shear-wave elastography is a method that is increasingly used to assess muscle stiffness in clinical practice and human health research. Recently, shear-wave elastography has been suggested and used to assess exercise-induced muscle damage. This review aimed to summarize the current knowledge of the utility of shear-wave elastography for assessment of muscle damage. In general, the literature supports the shear-wave elastography as a promising method for assessment of muscle damage. Increases in shear modulus are reported immediately and up to several days after eccentric exercise, while studies using shear-wave elastography during and after endurance events are showing mixed results. Moreover, it seems that shear modulus increases are related to the decline in voluntary strength loss. We recommend that shear modulus is measured at multiple muscles within a muscle group and preferably at longer muscle lengths. While further studies are needed to confirm this, the disruption of calcium homeostasis seems to be the primary candidate for the underlying mechanism explaining the increases in shear modulus observed after eccentric exercise. It remains to be investigated how well the changes in shear modulus correlate with directly assessed amount of muscle damage (biopsy).

Acute Effects of Percussive Therapy on the Posterior Shoulder Muscles Differ Based on the Athlete's Soreness Response

Background

Percussive therapy is hypothesized to speed recovery by delivering gentle, rhythmic pulses to soft tissue. However, patients often present with a differential soreness response after percussive therapy, which may lead to altered clinical outcomes.

Purpose

To compare the acute effects of percussion therapy on passive range of motion (ROM) and tissue-specific ultrasound measures (pennation angle [PA] and muscle thickness [MT]) between healthy individuals responding positively vs. negatively to percussive therapy performed on the dominant arm posterior rotator cuff.

Study Design

Cross-sectional laboratory study.

Methods

Fifty-five healthy individuals were assessed on a subjective soreness scale before and after a five-minute percussive therapy session on the dominant arm posterior rotator cuff muscles. Participants with no change or a decrease in muscle soreness were assigned to the positive response group and participants who reported an increase in muscle soreness were assigned to the negative response group. Passive internal rotation (IR) and external rotation (ER) ROM and strength, and muscle architecture of the infraspinatus and teres minor were measured via ultrasound on the dominant shoulder. All dependent variables were collected before percussive therapy, and 20 minutes following percussive therapy.

Results

The positive response group had greater improvements than the negative response group in dominant arm IR ROM (2.3° positive vs. -1.3° negative, p=0.021) and IR strength (1.1 lbs vs. -1.2 lbs, p=0.011) after percussive therapy. No differences in ER strength or ROM were observed between groups. Regarding muscle architecture, the positive group had a lesser change in teres minor MT (0.00 mm vs. 0.11 mm, p=0.019) after percussive therapy. All other muscle architecture changes were not statistically different between groups.

Conclusion

Participants with a positive response to percussive therapy had increased dominant arm IR ROM and IR strength, and decreased teres minor MT, after percussive therapy compared to the negative response participants.

Level of Evidence

III.

Effects of an external pneumatic compression device vs static compression garment on peripheral circulation and markers of sports performance and recovery

PURPOSE

To identify the effects of a single 30 min partial lower leg external pneumatic compression (EPC) treatment compared to a static compression (SC) garment or a no treatment control (CTL) on markers of recovery and performance following a muscle damaging protocol.

METHODS

Thirty healthy, active males (23 ± 3 years; 180.2 ± 9.0 cm; 81.6 ± 11.3 kg) performed 100 drop jumps from a 0.6 m box followed by a randomized, single 30 min treatment of either a partial lower leg EPC device worn below the knee and above the ankle (110 mmHg), SC garment (20-30 mmHg) covering the foot and calf just below the knee, or no treatment CTL, and then returned 24 and 48 h later. Participants were assessed for measures of muscle soreness, fatigue, hemodynamics, blood lactate, muscle thickness, circumferences, and performance assessments.

RESULTS

The drop jump protocol significantly increased muscle soreness (p < 0.001), fatigue (p < 0.001), blood flow (p < 0.001), hemoglobin (p < 0.001), and muscle oxygen saturation (SMO₂; p < 0.001). Countermovement jump and squat jump testing completed after treatment with either EPC, SC, or CTL revealed no differences for jump height between any condition. However, EPC treatment maintained consistent braking force and propulsive power measures across all timepoints for countermovement jump testing. EPC and SC treatment also led to better maintenance of squat jump performance for average relative propulsive force and power variables at 24 and 48 h compared to CTL.

CONCLUSIONS

A single 30 min partial leg EPC treatment may lead to more consistent jump performance following a damaging bout of exercise.

Effect of Resonant Frequency Vibration on Delayed Onset Muscle Soreness and Resulting Stiffness as Measured by Shear-Wave Elastography

This study utilized resonant frequency vibration to the upper body to determine changes in pain, stiffness and isometric strength of the biceps brachii after eccentric damage. Thirty-one participants without recent resistance training were randomized into three groups: a Control (C) group and two eccentric exercise groups (No vibration (NV) and Vibration (V)). After muscle damage, participants in the V group received upper body vibration (UBV) therapy for 5 min on days 1-4. All participants completed a visual analog scale (VAS), maximum voluntary isometric contraction (MVIC), and shear wave elastography (SWE) of the bicep at baseline (pre-exercise), 24 h, 48 h, and 1-week post exercise. There was a significant difference between V and NV at 24 h for VAS (p = 0.0051), at 24 h and 1-week for MVIC (p = 0.0017 and p = 0.0016, respectively). There was a significant decrease in SWE for the V group from 24-48 h (p = 0.0003), while there was no significant change in the NV group (p = 0.9341). The use of UBV resonant vibration decreased MVIC decrement and reduced VAS pain ratings at 24 h post eccentric damage. SWE was strongly negatively correlated with MVIC and may function as a predictor of intrinsic muscle state in the time course of recovery of the biceps brachii.

Effect of compression garments on muscle perfusion in delayed-onset muscle soreness: A quantitative analysis using intravoxel incoherent motion MR perfusion imaging

The aim of this prospective cohort study was to evaluate the effect of compression garments under resting conditions and after the induction of delayed-onset muscle soreness (DOMS) by MR perfusion imaging using intravoxel incoherent motion (IVIM). Magnetic resonance imaging of both lower legs of 16 volunteers was performed before and after standardized eccentric exercises that induced DOMS. A compression garment (21-22 mmHg) was worn during and for 6 h after exercise on one randomly selected leg. IVIM MR imaging, represented as total muscle perfusion D*f, perfusion fraction f and tissue diffusivity D, were compared between baseline and directly, 30 min, 6 h and 48 h after exhausting exercise with and without compression. Creatine kinase levels and T2-weighted images were acquired at baseline and after 48 h. DOMS was induced in the medial head of the gastrocnemius muscle (MGM) in all volunteers. Compression garments did not show any significant effect on IVIM perfusion parameters at any time point in the MGM or the tibialis anterior muscle (p > 0.05). Microvascular perfusion in the MGM increased significantly in both the compressed and noncompressed leg between baseline measurements and those taken directly after and 30 min after the exercise: the relative median f increased by 31.5% and 24.7% in the compressed and noncompressed leg, respectively, directly after the exercise compared with the baseline value. No significant change in tissue perfusion occurred 48 h after the induction of DOMS compared with baseline. It was concluded that compression garments (21-22 mmHg) do not alter microvascular muscle perfusion at rest, nor do they have any significant effect during the regeneration phase of DOMS. In DOMS, only a short-term effect of increased muscle perfusion (30 min after exercise) was observed, with normalization occurring during regeneration after 6-48 h. The normalization of perfusion independently of compression after 6 h may have implications for diagnostic and therapeutic strategies and for the better understanding of pathophysiological pathways in DOMS.

Quantifiable Contrast-Enhanced Ultrasound Explores the Role of Protection, Rest, Ice (Cryotherapy), Compression and Elevation (PRICE) Therapy on Microvascular Blood Flow

The aim of this randomized controlled laboratory study was to evaluate the role of standardized protection, rest, ice (cryotherapy), compression and elevation (PRICE) therapy on microvascular blood flow in human skeletal muscle. Quantifiable contrast-enhanced ultrasound was used to analyze intramuscular tissue perfusion (ITP) of the rectus femoris (RF) and vastus intermedius (VI) muscles in 20 healthy athletes who were randomly assigned to PRICE or control groups. Baseline perfusion measurements (resting conditions, T₀) were compared with cycling exercise (T₁), intervention (PRICE or control, T₂) and follow-up at 60 min post-intervention (T₃). The 20 min PRICE intervention included rest, cryotherapy (3°C), compression (35 mm Hg) and elevation. After intervention, PRICE demonstrated a decrease of ITP in VI (-47%, p = 0.01) and RF (-50%, p = 0.037) muscles. At T_3, an ongoing decreased ITP for the RF (p = 0.003) and no significant changes for the VI were observed. In contrast, the control group showed an increased ITP at T₂ and no significant differences at T₃. PRICE applied after exercise led to a down-regulation of ITP, and the termination of PRICE does not appear to be associated with a reactive hyperemia for at least 60 min after treatment.

Multi-Parametric Analysis of Below-Knee Compression Garments on Delayed-Onset Muscle Soreness

To investigate below-knee compression garments during exercise and a post-exercise period of 6 h on clinical, functional, and morphological outcomes in delayed-onset muscle soreness (DOMS). Eighteen volunteers (age: 24.1 ± 3.6, BMI 22.7 ± 2.7 kg/m²) were enrolled. Measures were acquired at baseline, 6 h, and 48 h after eccentric and plyometric exercise, with wearing a compression garment (21-22 mmHg) on a calf during and for the first 6 h after exercise. 3T MRI was performed for quantification of intramuscular edema (T2 signal intensity (SI), T2 time, and manual volume segmentation); jump height, calf circumference, ankle dorsiflexion (DF), creatine kinase (CK), and muscle soreness were assessed. DOMS was confirmed in all participants after 48 h, with an increase in soreness (p < 0.001) and CK (p = 0.001), decrease in jump height (p < 0.01), and the presence of intramuscular edema (p < 0.01) in both the compressed and non-compressed limbs. No differences between the compressed and non-compressed limbs were observed for muscle soreness and jump height. MRI T2 SI, T2 time, soreness, and manual segmentation revealed no effect of the compression treatment. The assessment of calf circumference and DF showed no changes in either the compression or non-compression limb (p = 1.0). Wearing compression garments during combined eccentric and plyometric exercise and for 6 h post-exercise has no effect on clinical signs of DOMS, jump performance, or the development of intramuscular edema.

Ankle flossing alters periarticular stiffness and arterial blood flow in asymptomatic athletes

BACKGROUND

Tissue flossing has been introduced to increase impaired range of motion (ROM) and flexibility, to enhance prevention and rehabilitation, as well as to improve athletic performance; however, limited evidence exists for its efficacy. The aim of the present study was to evaluate the effects of ankle flossing on periarticular stiffness and perfusion via Acoustic Radiation Force Impulse (ARFI) elastography and Power Doppler Sonography (PDS).

METHODS

Twenty-one healthy students (age: 24±2 years, BMI: 22±3 kg/m²) were recruited as participants. ARFI was performed to evaluate periarticular ankle stiffness involving the anterior ankle capsule (AC), the anterior talofibular ligament (ATFL) and the peroneus brevis muscle (PBM). Arterial blood flow was assessed in the dorsal pedal artery. Measurements were taken under resting conditions (T<inf>0</inf>) and twice after standardized ankle flossing (T<inf>1</inf>: 0 min., T<inf>2</inf>: 60 min. postintervention).

RESULTS

The connective tissue stiffness decreased significantly after ankle flossing compared to baseline (T<inf>1</inf>, AC: -12%, P=0.009, ATFL: -12%, P=0.003; T<inf>2</inf>, AC: -8%, P=0.002, ATFL: -9%, P=0.015). The PBM stiffness decreased by 3% (T<inf>1</inf>, P=0.304) and 4% (T<inf>2</inf>, P=0.029). The perfusion measures significantly increased by 30% at T<inf>1</inf> compared to baseline (P=0.001); no significant changes were observed at T<inf>2</inf> (P=0.492).

CONCLUSIONS

This is the first study demonstrating decreased AC and ATFL stiffness and reactive hyperemia to be key mechanisms of ankle flossing. Additional studies must be conducted to determine whether changes in biomechanical properties influence dynamic ankle stability.

Different Effects of Foam Rolling on Passive Tissue Stiffness in Experienced and Nonexperienced Athletes

CONTEXT

Foam rolling (FR) has been developed into a popular intervention and has been established in various sports disciplines. However, its effects on target tissue, including changes in stiffness properties, are still poorly understood.

OBJECTIVE

To investigate muscle-specific and connective tissue-specific responses after FR in recreational athletes with different FR experience.

DESIGN

Case series.

SETTING

Laboratory environment.

PARTICIPANTS

The study was conducted with 40 participants, consisting of 20 experienced (EA) and 20 nonexperienced athletes (NEA).

INTERVENTION

The FR intervention included 5 trials per 45 seconds of FR of the lateral thigh in the sagittal plane with 20 seconds of rest between each trial.

MAIN OUTCOME MEASURES

Acoustic radiation force impulse elastosonography values, represented as shear wave velocity, were obtained under resting conditions (t0) and several times after FR exercise (0 min [t1], 30 min [t2], 6 h [t3], and 24 h [t4]). Data were assessed in superficial and deep muscle (vastus lateralis muscle; vastus intermedius muscle) and in connective tissue (iliotibial band).

RESULTS

In EA, tissue stiffness of the iliotibial band revealed a significant decrease of 13.2% at t1 (P ≤ .01) and 12.1% at t3 (P = .02). In NEA, a 6.2% increase of stiffness was found at t1, which was not significantly different to baseline (P = .16). For both groups, no significant iliotibial band stiffness changes were found at further time points. Also, regarding muscle stiffness, no significant changes were detected at any time for EA and NEA (P > .05).

CONCLUSIONS

This study demonstrates a significant short-term decrease of connective tissue stiffness in EA, which may have an impact on the biomechanical output of the connective tissue. Thus, FR effects on tissue stiffness depend on the athletes' experience in FR, and existing studies have to be interpreted cautiously in the context of the enrolled participants.

Accelerating Recovery from Exercise-Induced Muscle Injuries in Triathletes: Considerations for Olympic Distance Races

The triathlon is one of the fastest developing sports in the world due to expanding participation and media attention. The fundamental change in Olympic triathlon races from a single to a multistart event is highly demanding in terms of recovery from and prevention of exercise-induced muscle injures. In elite and competitive sports, ultrastructural muscle injuries, including delayed onset muscle soreness (DOMS), are responsible for impaired muscle performance capacities. Prevention and treatment of these conditions have become key in regaining muscular performance levels and to guarantee performance and economy of motion in swimming, cycling and running. The aim of this review is to provide an overview of the current findings on the pathophysiology, as well as treatment and prevention of, these conditions in compliance with clinical implications for elite triathletes. In the context of DOMS, the majority of recovery interventions have focused on different protocols of compression, cold or heat therapy, active regeneration, nutritional interventions, or sleep. The authors agree that there is a compelling need for further studies, including high-quality randomized trials, to completely evaluate the effectiveness of existing therapeutic approaches, particularly in triathletes. The given recommendations must be updated and adjusted, as further evidence emerges.