Electromyographic activity of quadriceps muscles during eccentric squat exercises: implications for exercise selection in patellar tendinopathy

Background: Tendon injuries are commonly seen in sports medicine practice. Many elite players involved in high-impact activities develop patellar tendinopathy (PT) symptoms. Of them, a small percentage will develop refractory PT and need to undergo surgery. In some of these patients, surgery does not resolve these symptoms. Purpose: To report the clinical results in a cohort of athletes who underwent further surgery after failure of primary surgery for PT. Study Design: Case series; Level of evidence, 4. Methods: A total of 22 athletes who had undergone revision surgery for failed surgical management of PT were enrolled in the present study. Symptom severity was assessed through the Victorian Institute of Sport Assessment Scale for Patellar Tendinopathy (VISA-P) upon admission and at the final follow-up. Time to return to training, time to return to competition, and complications were also recorded. Results: The mean age of the athletes was 25.4 years, and the mean symptom duration from the index intervention was 15.3 months. At a mean follow-up of 30.0 ± 4.9 months, the VISA-P score improved 27.8 points ( P < .0001). The patients returned to training within a mean of 9.2 months. Fifteen patients (68.2%) returned to competition within a mean of 11.6 months. Of these 15 patients, a further 2 had decreased their performance, and 2 more had abandoned sports participation by the final follow-up. The overall rate of complications was 18.2%. One patient (4.5%) had a further revision procedure. Conclusion: Revision surgery was feasible and effective in patients in whom PT symptoms persisted after previous surgery for PT, achieving a statistically significant and clinically relevant improvement of the VISA-P score as well as an acceptable rate of return to sport at a follow-up of 30 months.

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Changes in electromyographic activity, mechanical power, and relaxation rates following inspiratory ribcage muscle fatigue

Scientific Reports ◽

10.1038/s41598-021-92060-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Antonio Sarmento ◽

Guilherme Fregonezi ◽

Maria Lira ◽

Layana Marques ◽

Francesca Pennati ◽

...

Keyword(s):

Muscle Fatigue ◽

Low Frequency ◽

Mechanical Power ◽

Electromyographic Activity ◽

Median Frequency ◽

Relaxation Rates ◽

Shortening Velocity ◽

Inspiratory Muscles ◽

Underlying Mechanisms

AbstractMuscle fatigue is a complex phenomenon enclosing various mechanisms. Despite technological advances, these mechanisms are still not fully understood in vivo. Here, simultaneous measurements of pressure, volume, and ribcage inspiratory muscle activity were performed non-invasively during fatigue (inspiratory threshold valve set at 70% of maximal inspiratory pressure) and recovery to verify if inspiratory ribcage muscle fatigue (1) leads to slowing of contraction and relaxation properties of ribcage muscles and (2) alters median frequency and high-to-low frequency ratio (H/L). During the fatigue protocol, sternocleidomastoid showed the fastest decrease in median frequency and slowest decrease in H/L. Fatigue was also characterized by a reduction in the relative power of the high-frequency and increase of the low-frequency. During recovery, changes in mechanical power were due to changes in shortening velocity with long-lasting reduction in pressure generation, and slowing of relaxation [i.e., tau (τ), half-relaxation time (½RT), and maximum relaxation rate (MRR)] was observed with no significant changes in contractile properties. Recovery of median frequency was faster than H/L, and relaxation rates correlated with shortening velocity and mechanical power of inspiratory ribcage muscles; however, with different time courses. Time constant of the inspiratory ribcage muscles during fatigue and recovery is not uniform (i.e., different inspiratory muscles may have different underlying mechanisms of fatigue), and MRR, ½RT, and τ are not only useful predictors of inspiratory ribcage muscle recovery but may also share common underlying mechanisms with shortening velocity.

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Focused Extracorporeal Shockwave Therapy in Physical Medicine and Rehabilitation

Current Physical Medicine and Rehabilitation Reports ◽

10.1007/s40141-020-00306-z ◽

2020 ◽

Author(s):

Richard Crevenna ◽

Michael Mickel ◽

Othmar Schuhfried ◽

Christina Gesslbauer ◽

Andrej Zdravkovic ◽

...

Keyword(s):

Pain Syndrome ◽

Surrounding Tissue ◽

Patellar Tendinopathy ◽

Physical Medicine ◽

Physical Treatment ◽

Extracorporeal Shockwave Therapy ◽

Non Union ◽

Extracorporeal Shockwave ◽

Shockwave Therapy ◽

Physical Medicine And Rehabilitation

Abstract Purpose of Review Focused extracorporeal shockwave therapy (fESWT) is a physical treatment modality developed over the last 25 years for musculoskeletal indications. It has many indications in the field of physical medicine and rehabilitation (PM&R) and is effective, time-efficient, and cost-efficient. This review focuses on basics and on clinical indications as well as on significant trends in fESWT. Recent Findings In PM&R, stimulation of healing processes in tendons, surrounding tissue, and bones via mechanotransduction seems to be a relevant biological effect. The International Society for Medical Shockwave Treatment (ISMST) describes different types of indications (such as approved standard indications—in accordance with most scientific evidence—like calcifying tendinopathy of the shoulder, plantar fasciitis lateral epicondylopathy of the elbow, greater trochanter pain syndrome, patellar tendinopathy, Achilles tendinopathy and bone non-union, common empirically tested clinical uses, exceptional or expert indications, and experimental indications). Summary fESWT is a relevant treatment option in PM&R and regenerative medicine. In recent years, historical paradigms (for example, application in cancer patients) have changed and new indications (such as nerve regeneration, myofascial trapezius syndrome, low back pain, dermatosclerosis, and lymphedema) are supported. Future translational research should focus on establishing actual exceptional indications and experimental indications for clinical routine.

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