BFR & Muscle Injuries

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Hamstring pulls or strains are one of the most common injuries amongst athletes. They have a reputation for lingering and reoccurring throughout the season.

When a muscle is injured, Myostatin and TGF beta act together to fill in the tear with fibrotic tissue. Unfortunately fibrotic tissue or scar tissue, is not as elastic as muscle and tends to break or rip instead of stretch.

BFR has been proven to produce muscle hypertrophy & protein synthesis at loads far below the traditional 65-85% 1RM without the coinciding muscle breakdown, which makes it a great way to load injured muscle tissue.

Low load BFR exercise takes away oxygen as a fuel source and allows aerobic movement tasks to be carried out by the anaerobic system.  Anaerobic muscle activity creates lactate build-up which initiates Growth Hormone release and subsequent collagen synthesis essential for tissue healing.

BFR has been found to down regulate Myostatin, this means that if we use BFR with our muscle injuries we may have a better chance of obtaining true non-fibrotic healing of the muscle tissue.

Above is a progression of low load exercises that have been working for my athletes.

High vs Low Ankle Sprains

By Grant Uyemura, DPT

High ankle sprains are more common in high impact sports and usually occur when the
foot is forced into external rotation with a planted, dorsiflexed foot. This mechanism of injury will cause the talus to widen the ankle mortise which can injure or tear the syndesmosis. The syndesmosis is made up of the anterior inferior tibiofibular ligament, interosseous ligament, interosseous membrane, posterior inferior tibiofibular ligament, and transverse ligament.

Lateral ankle sprains also known as inversion sprains are the most common orthopedic
injury and account for 85% of all ankle injuries. Lateral ankle sprains usually happen when the foot is point down, plantarflexed and rolls inward. The anterior talofibular, calcaneofibular, and posterior talofibular ligaments are the most common ligaments to get injured during a lateral ankle sprain.

High ankle sprains will take longer to heal and are more likely to create long-term
dysfunction compared to lateral ankle sprains. However, high ankle sprains are less common than lateral ankle sprains. Both injuries can be treated through physical therapy with conservative treatments.

The first phase will be protecting the joint while minimize pain, inflammation, weakness, and loss of motion.

The second phase will focus on normalizing joint mobility, strength, neuromuscular control, and return to activities of daily living.

The last phase will prepare the athlete for return to sport activities.

img_2534Blog post written by Grant Uyemura, DPT Student from University of St. Augustine. At the time of publishing Grant was in a clinical rotation with me at Catz PTI.

References:

1. Williams GN, Allen EJ. Rehabilitation of Syndesmotic (High) Ankle Sprains. Sport Heal A Multidiscip Approach. 2010;2(6):460-470. doi:10.1177/1941738110384573.

2. Hunt K. J, Phisitkul, P Pirolo J, Amendola A. High Ankle Sprains and Syndesmotic Injuries in Athletes. Journal of the American Academy of Orthopaedic Surgeons. .
2015;23(11):661-673. doi:10.5435/jaaos-d- 13-00135

3. Albin, S. Rehabilitation of the Athlete Following Ligamentous Injury. Oral Presentation at: 12 th Annual CU Sports Medicine Fall Symposium. Meeting; September 22. 2017; Boulder,
CO.

Concussion: When Can I Return to Sport?

By Grant Uyemura, DPT Student

A concussion is a mild traumatic brain injury (TBI) that occurs when a head impact jars or shakes the brain inside the skull. This can damage neural pathways, which can lead to neurological disturbances. Symptoms can affect your physical, cognitive, behavioral, and emotional well-being.

Physical signs such as headaches, dizziness, sleep disturbances, nausea, vomiting, noise & light sensitivity, loss of consciousness.

Cognitive signs are confusion, slow reaction time, memory problems, poor judgement, inability to focus.

Behavioral changes may be confrontational demeanor, explosive temper fearfulness, impatient, hypervigilance.

Emotional changes such as depression, agitation, irritability, anxiety, and frequent mood changes man also be experienced. 90% of diagnosed concussions do not involve loss of consciousness, so it is important to understand common signs and symptoms.

Return to Sport Stages

Following a concussion, it is recommended to rest for 24-48 hours before starting stage
1 of the return to sport protocol. If the athlete is able to complete the stage without concussion related symptoms, then they can progress to the next stage. There should be at least 24 hours for each step of the progression. At minimum, it would take athletes 1 week to proceed through the full rehabilitation protocol before returning to play.

img_2534 Blog post written by Grant Uyemura, DPT Student from University of St. Augustine. At the time of publishing Grant was in a clinical rotation with me at Catz PTI.

References:

1. McCrory P, Meeuwisse W, Dvorak J, et al Consensus statement on concussion in sport—the 5 th  international conference on concussion in sport held in Berlin, October 2016 Br J Sports Med Published Online First: 26 April 2017. doi: 10.1136/bjsports-2017- 097699

2. Parker M, Lecture presented: Mild Traumatic Brain Injury, How to Identify and Treat
Concussions with Compassion at the University of Saint Augustine for Health Sciences, San Marcos, CA.

Why is the Rotator Cuff Important?

By Grant Uyemura, DPT Student

Rotator cuff tendinopathies affect 20-30% of the general population and becomes more prevalent and disabling with age. 1 The rotator cuff is made up of 4 muscles supraspinatus, infraspinatus, teres minor, and subscapularis. These muscles help stabilize the humeral head within the glenoid fossa and prevent superior humeral head migration during overhead movements. 2

Weakness of the rotator cuff can lead to shoulder impingement, tendonitis, bursitis, and labral tears. Looking at Jobe’s instability continuum. 3
1. Rotator cuff weakness generally occurs first
2. Functional instability follows prolonged rotator cuff weakness
3. Capsular laxity, which develops over time
4. Subluxation due to inability of the humeral head to center in the glenoid during motion
5. Rotator cuff/labral tearing (late-stage disease of secondary impingement)

Best Exercises

Reinold et al., 2,4 found that the best supraspinatus exercise was a standing or prone full can. A standing full can was found to have decreased deltoid activation compared to the prone full can. Sidelying external rotation with 0º of abduction was found to be the best exercise to strengthen the infraspinatus and teres minor. Internal rotation at 0º or 90º of abduction was the best exercise to strengthen the subscapularis. Click here or photos for link to videos.

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These isolated exercises are a good starting point and are great for a basic home program.  However, for best results they should be used in conjunction with a more comprehensive and integrated rehab routine.

img_2534Blog post written by Grant Uyemura, DPT Student from University of St. Augustine. At the time of publishing Grant was in a clinical rotation with me at Catz PTI.

References:

1. Wies JT, Humphreys H, Latham M, et al. A randomized placebo-controlled trial of PT for RTC tendinopathies [abstract]. J Orthop Sports Phys Ther. 2005;35:A5.

2. Reinold MM, Escamilla R, Wilk KE. Current Concepts in the Scientific and Clinical
Rationale Behind Exercises for Glenohumeral and Scapulothoracic Musculature. J Orthop
Sport Phys Ther. 2009;39(2):105-117. doi:10.2519/jospt.2009.2835.

3. Page P, Frank C, Lardner R. Assessment And Treatment Of Muscle Imbalance. Champaign [etc.]: Human kinetics; 2010.

4. Reinold MM, Wilk KE, Fleisig GS, et al. Electromyographic Analysis of the Rotator Cuff
andDeltoid Musculature During Common Shoulder External Rotation Exercises. J Orthop
Sport Phys Ther. 2004;34(7):385-394. doi:10.2519/jospt.2004.34.7.385.

Why are Strong Glutes Important?


By Grant Uyemura, DPT Student

What do the glutes do?

The glute is made up of 3 muscles glute maximus, medius, and minimus. The main action of the glute maximus is hip extension and external rotation. The glute medius acts as a hip abductor with anterior fibers assisting internal rotation while the posterior fibers aid in external rotation. The glute minimus is responsible for hip abduction and internal rotation.Why are strong glutes important?

Weak glutes can cause low back/hip pain, iliotibial band syndrome, patellofemoral pain
syndrome, and chronic ankle sprains.

Best exercises for glutes?

According to Distefano et al. they found the best glute medius exercises were side-lying hip abduction and the best glute maximus exercises was the single leg deadlifts and single leg squat. Boren et al. found that a front plank with hip extension was the best glute maximus exercise while a side plank with hip abduction was best for the glute medius. Both studies found that the best overall exercise for glute strengthening was a single leg squat.

img_2534Blog post written by Grant Uyemura, DPT Student from University of St. Augustine. At the time of publishing Grant was in a clinical rotation with me at Catz PTI.

1. Boren K, Conrey C, Le Coguic J, Paprocki L, Voight M, Robinson TK. Electromyographic
analysis of gluteus medius and gluteus maximus during rehabilitation exercises. Int J
Sports Phys Ther. 2011;6(3):206-223.

2. Distefano LJ, Blackburn JT, Marshall SW, Padua DA. Gluteal Muscle Activation During
Common Therapeutic Exercises. J Orthop Sport Phys Ther. 2009;39(7):532-540.
doi:10.2519/jospt.2009.2796.

3. Macadam P, Cronin J, Contreras B. an Examination of the Gluteal Muscle Activity
Associated With Dynamic Hip Abduction and Hip External Rotation Exercise: a Systematic Review. Int J Sports Phys Ther. 2015;10(5):573-591.

What is Femoroacetabular Impingment?

By Grant Uyemura, DPT Student

Femoroacetabular Impingement (FAI) is abnormal contact between the femoral head and acetabulum, which can cause hip pain, labrum, and/or cartilage damage. There are three different types of FAI’s: Cam, Pincer, and mixed. Cam impingement lesions are more prevalent in younger males than in females. Pincer lesions are more common in middle aged, active women.1 A study by Tannast et al. found that 86% of patients have a combination of both cam and pincer impingement.2

Types of FAI

Cam: Aspherical femoral head tries to fit into a spherical socket. Can cause chondrolabral junction separation due to shearing force.

Pincer: Over coverage of acetabulum socket, can cause labrum crushing and degeneration/ ossification.

Mixed: Combination of cam and pincer deformities.
Clinical Presentation

• Anterior or anterolateral hip/groin pain

• Stiffness

• Painful hip flexion past 90º and internal rotation

• Pain with prolonged sitting

What Physical Therapy can do?

The goal of physical therapy is to increase range of motion, increase strength, and decrease pain in order to maximize function and return to your prior level of function. Surgery should only be considered when conservative treatments do not control symptoms or functional limitations are unacceptable.4

 Blog post written by Grant Uyemura, DPT Student from University of St. Augustine. At the time of publishing Grant was in a clinical rotation with me at Catz PTI.

References:

1. ​Kuhns BD, Weber AE, Levy DM, Wuerz TH. The Natural History of Femoroacetabular Impingement. Front Surg. 2015;2(November):1-7. doi:10.3389/fsurg.2015.00058.

2. ​Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular impingement: Radiographic diagnosis – What the radiologist should know. Am J Roentgenol. 2007;188(6):1540-1552. doi:10.2214/AJR.06.0921.

3. ​Stephanie Pun, MD, Deepak Kumar, PT, PhD, and Nancy E. Lane M. Femoroacetabular Impingement. Nih. 2016;67(1):17-27. doi:10.1002/art.38887.Femoroacetabular.

4. ​Enseki K, Harris-Hayes M, White DM, et al. Nonarthritic Hip Joint Pain. J Orthop Sport Phys Ther. 2014;44(6):A1-A32. doi:10.2519/jospt.2014.0302.

 

 

 

Progressive Overload: A Strength Training Model for The Rehab Professional


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By Teddy Wilsey, DPT, CSCS

It is well known that the body must be broken down in order to build up. This is the fundamental principle of exercise: stress adaptation occurs in order to strengthen our bones, condition our cardiovascular system, maintain our joint range of motion, and optimize our muscular function. If you don’t use it, you will lose it. This idea of invoking stress is an area that rehabilitation professionals often fall short in. The physical therapy curriculum is designed to prepare a generalist who can work with all levels of patients including pediatrics, hospital work, and neurological rehab. These are all very important aspects of healthcare, however, the major downfall of a generalized therapist degree is a lack of knowledge in sports rehab and basic strength and conditioning. This article will touch on the need to stress the system in orthopedic rehabilitation and the idea of progressive overload within a linear periodization rehabilitation model.

Performance is a relative term, as the performance ceiling for a 75 year old recovering from a knee replacement is vastly different than that of a college basketball player recovering from an ACL rupture and patellar tendon autograft. Either way, they are both knee injuries and the principles remain the same. Regaining quadriceps strength will be an integral part of both of their programs, and the exercises might be very similar at the beginning phases. As mentioned in the introduction, physiological adaptation and increases in performance require stress to the system. It’s important to understand that stress is relative. An exercise or weight load that might cause stress and elicit strength and gains for the 75 year old would probably not be of the same benefit for the college basketball player. This same weight could even create negative adaptations over time if it is not sufficient to stimulate the system. For example, if a 400 lb. squater is only doing goblet squats with 25 lb., they will actually get weaker while working with you.

The therapist’s job is help their patients increase function. From an orthopedic recovery standpoint, therapists must cause some amount of stress in order to help their patients improve function. Most therapists typically see their patients for 2-6 months at the most, depending on the injury. Although linear progress is not a long term solution to training, it lends itself well to this shorter time period and rehabilitation type of recovery where exercise selection is constantly being progressed. Strength and conditioning periodization models are helpful to understand from a theoretical standpoint, but are typically more complex than we need for therapy. In the simplest of terms: just make sure your patient is doing more than they were two weeks ago.

To examine progressive overload, stress, and a linear model, let’s look at integrating the squat into rehabilitation for both of these patients. Outside of gait, the squat is arguably the most functional movement that exists. Standing up is an essential skill for nearly everyone. To start with the 75 year old patient s/p total knee, their sit to stand would likely begin with an upper extremity assist and a very short range of motion to a high box. Loading the knee will assist in gradually restoring range of motion and alleviating stiffness. Manual therapy, stretching, and other passive modalities can help with managing pain and improving range of motion as well. This patient’s knee will likely be stiff, and the soft tissue structures surrounding the knee may be weak and shortened as well. The typical arthritic knee experiences months to years of progressive weakening and range of motion loss prior to surgery. Rehabilitation prior to surgery should focus on maintaining and regaining full range of motion and improving strength to tolerance.

The first day or two after surgery for these two patients might look very similar. The college basketball player ACL repair will also start a squat with a TRX. After the second or third PT session, the college athlete will require much more challenge to make progress. They might be more comfortable achieving parallel depth sooner, as their tissue was supple prior to surgery. In this patient, there will also be a need to be emphasize slowly increasing the stretch across the patellar tendon. This is due to the patellar tendon autograft. The squat will start with a vertical tibia, and the therapist will gradually cue the patient and modify exercises to allow more dorsiflexion and knee flexion over time in order to rebuild the surgical site and increase patellar loading.

By 6-8 weeks, both of these patients should be squatting with weight. The total knee might be nothing more than 10-20 lb. goblet squat, or it could be up to a 50 or 60 lb. goblet squat, depending on their prior function. The basketball player might be in that 40-60 lb. range for a goblet, or even back squatting 135 lb. or more. Again, this depends on prior strength levels.  Both of these patients should be exposed to similar relative stressors. They should both feel muscular soreness at times. They might both even feel some increased knee soreness during periods of introducing new movements or taking big steps forward. That’s usually OK. The important distinction here is that the stress for a college athlete’s rehab needs to be significantly higher than that of a knee replacement patient in order to evoke adaptation.

Rehabilitation professionals often fall short in is creating enough stress and adaptation for their higher level athletes. The typical outpatient therapist’s caseload is probably only 10-20% athletes, at the most. Hence, the potential blind spot and need for a greater understanding of how to help challenge athletes. The concepts are the same across the board, but there needs to be a greater understanding of the nuances of higher level and more challenging exercise and movement. Remember, without stress and progressive overload, there is very minimal adaptation.

To learn more about how to challenge athletes and what exercises to use, check out my instagram at @strengthcoachtherapy.

Healthy-Baller-Teddy-300x300Dr. Teddy Willsey, DPT, CSCS, is the director of sports medicine at Healthy Baller, a sports performance gym located in Rockville, MD, a suburb of Washington D.C. In addition to his daily practice, Teddy writes, speaks, and posts on social media regularly with the goal of educating therapists, fitness professionals, and recreational exercises on practical approaches to exercise and rehabilitation with a sports medicine and performance focus. Teddy’s work can be found on Instagram: @strengthcoachtherapy

Meniscal Tears & Consideration of PT Instead of Surgery

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By Greg Louie, DPT

The menisci lie between the tibia and femur. They stabilize the knee into flexion and extension, assist in joint lubrication and nutrition, and distribute compressive forces to reduce stress on the articular cartilage with load-bearing and load transmission.(1) Meniscal tears are quite common,the mean annual incidence of meniscal injuries are 66 for every 100,000 individuals.(2)

There are two classifications of meniscal tears: traumatic and degenerative. For a meniscus tear to classified as traumatic, the meniscus must be healthy and there must be an injury to the knee as a result of a forced movement.(3) These types of tears are higher amongst young adults because of an increased percentage of this population participating in high-level activities and sports.(4) A forced twisting movement with the knee bent is the common mechanism of injury for traumatic lesions. Degenerative tears occur in the absence of trauma and result from deterioration of the meniscus from abnormal loading forces to the knee.(3) Individuals with a body mass index greater than 25, those who are older then 60, and those who work in jobs requiring increased kneeling, squatting, and stair climbing are at a significantly higher risk for degenerative meniscal tears.(4)

Meniscus injures are often accompanied by other ligamentous injuries of the knee.(3) A combination of injury to the meniscus, medial collateral ligament, and the anterior cruciate ligament is known as the unhappy triad of the knee.(5)

In the United States, partial meniscectomies are the most common orthopedic surgical procedure(6) but does this mean everyone with a torn meniscus should opt for surgery? Several studies have found that surgery is not always necessary and that physical therapy should be considered prior to surgery. Sihvonon and associates found no difference in partial menisectomy compared to sham surgery.(7) Katz and colleagues found no difference in outcomes with arthroscopic partial meniscectomy combined with physical therapy compared to physical therapy alone.(8) Surgery should be considered as a last resort when all other interventions (including physical therapy) have failed.

A physical therapist will assess the severity of the tear and provide interventions to control the pain, inflammation, and swelling. As the knee beings to heal, they can help you regain full range of motion, get you back walking pain free, and build strength and coordination to prevent reinjury.

Greg Blog post written by Greg Louie, DPT Student from University of St. Augustine. At the time of publishing Greg was in a clinical rotation at Catz PTI. Follow him on Instagram @sportsperformancerehab

References:

1. Makris EA, Hadidi P, Athanasiou KA. The knee meniscus: structure-function, pathophysiology, current repair techniques, and prospects for regeneration. Biomaterials. 2011;32(30):7411-7431.

2. Hede A, Jensen DB, Blyme P, et al. Epidemiology of meniscal lesions in the knee. Acta Orthop Scand. 1990; 61:435–437.

3. http://www.physio-pedia.com/Meniscal_Lesions

4. Snoeker BA, Bakker EW, Kegel CA, Lucas C Risk factors for meniscal tears: a systematic review including meta-analysis. J Orthop Sports Phys Ther 43: 352–367. 2885

5. Sbourne K, Nitz P. The O’Donoghue triad revisited. Combined knee injuries involving anterior cruciate and medial collateral ligament tears. Am J Sports Med. 19(5):474–7.

6. Englund M, Guermazi A, Gale D, et al. Incidental meniscal findings on knee MRI in middle-aged and elderly persons. N Engl J Med. 2008; 359:1108-1115.

7. Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. N Engl J Med. 2013; 369(26): 2515–24.

8. Katz JN, Brophy RH, Chaisson CE, et al. Surgery versus physical therapy for a meniscal tear and osteoarthritis. N Engl J Med. 2013; 368:1675-1684

Rotator Cuff Rehab Management

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By Garrett Holle, DPT Student

The function of the rotator cuff is colossal in the performance of our athletes and everyday individuals.  So much so, in fact, it has formerly been called the kiss of death for the career of overhead athletes.  Rotator cuff injury in sports is climbing in part due to an increased emphasis on strength in college programs. Moreover, in a study of NCAA college football players, rotator cuff injury was the 3rd most commonly reported shoulder injury (1). This high rate of occurrence holds true in the general public as
this study showed that of a random sample, 20.7% of patients had full-thickness rotator cuff tears (3).

As you can see, the ability to treat rotator cuff injuries and treat them well is going to be a valuable skill in your practice. The rehab is not easy, but we can make a huge difference with our patients if we handle them correctly.

How to Avoid a Common Oversight of Rotator Cuff Rehab

When prescribing exercise for the small intrinsic muscles of the cuff, it can be easy to throw the typical 3 sets of 12 to a patient.  However, I think we should reconsider this.  In addition to the typical explanation that every patient is different, there is also physiological evidence that supports this notion. This study explored the fiber composition of the rotator cuff muscles, indicating a mixed composition of fast and slow twitch (2). Although 44% of rotator cuff fibers labeled positively as slow twitch, the remaining fibers lie somewhere on the fast-twitch continuum.

Now if that study is a little too far into the physiology for you, let me make this applicable.

This knowledge of fiber type composition allows us to better determine and prescribe exercise volumes and intensities that satisfy the demands for muscle development. This concept aligns with the strength and conditioning principle of specificity. In the training realm, if you’re working with a sprinter, you’re going to utilize high intensity, low volume and if you’re training an endurance runner, you will use lower intensity with higher volumes. This example applies to training of the rotator cuff as well.

This concept is no nuance in the strength and conditioning realm, and it is a great illustration of how we can successfully begin to close the chasm between our two professions.

Garrett 2 Garrett Holle is a DPT student at the University of Kansas Medical Center. You can find him on all social media platforms @Holle_Per4mance 

References

1. Kaplan, L. D., Flanigan, D. C., Norwig, J., Jost, P., & Bradley, J. (2005). Prevalence and Variance of Shoulder Injuries in Elite Collegiate Football Players. The American Journal of Sports Medicine, 33(8), 1142–1146. https://doi.org/10.1177/0363546505274718

2. Lovering, R. M., & Russ, D. W. (2008). Fiber Type Composition of Cadaveric Human Rotator Cuff Muscles. Journal of Orthopaedic & Sports Physical Therapy, 38(11), 674–680. https://doi.org/10.2519/jospt.2008.2878

3. Yamamoto, A., Takagishi, K., Osawa, T., Yanagawa, T., Nakajima, D., Shitara, H., & Kobayashi, T. (2010). Prevalence and risk factors of a rotator cuff tear in the general population. Journal of Shoulder and Elbow Surgery, 19(1), 116–120. https://doi.org/10.1016/j.jse.2009.04.006

4. Rotator Cuff Image: Henry Vandyke Carter [Public domain], via Wikimedia Commons

 

Groin Strains

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By Ashley Pena, DPT

Groin strains make up 8- 18% of all soccer injuries and also occur in many other high intensity sports such as Ice Hockey, Football, Basketball, and more. They are typically found to occur during kicking, cutting, pivoting, changing directions, or when planting the lead foot. In a prospective research study looking at the athletic population, Serner et. al. found that in soccer players, kicking was the most common mechanism of injury at 40%. In other sports, changing directions was the most frequent mechanism at 31%. In addition, Serner found that 66% of these groin strains resulted in injuries to the Adductors (primarily Adductor Longus). Iliopsoas and Proximal Rectus Femoris were also found to be frequently injured with 15-25% of the groin strain participants sustaining these injuries.

Some factors which have been found in past research to be related to an increased risk of groin strains include older age, level of competition or experience, decreased range of hip abduction and rotation, isometric adductor muscle weakness or high abductor/adductor strength ratio, and poor performance in vertical jump tests. Specifically, in a cohort study done by Moreno-Perez et. al. it was found that players with groin injuries showed weaker isometric hip adductor strength and smaller Adductor/Abductor strength ratios than those without groin injuries giving evidence that screening for adductor strength deficits or Add/ Abd. muscle imbalances may be helpful in avoiding groin injuries.

ashleyBlog Post written by Ashley Pena, DPT Student from Cal State Northridge. At the time of publishing, Ashley was in her final clinical rotation with me at Catz PTI.

References:

  1. Elattar O, Choi H-R, Dills VD, Busconi B. Groin Injuries (Athletic Pubalgia) and Return to Play. Sports Health: A Multidisciplinary Approach. 2016;8(4):313-323. doi:10.1177/1941738116653711.
  2. Moreno-Pérez V, Lopez-Valenciano A, Barbado D, Moreside J, Elvira J, Vera-Garcia F. Comparisons of hip strength and countermovement jump height in elite tennis players with and without acute history of groin injuries. Musculoskeletal Science and Practice. 2017;29:144-149. doi:10.1016/j.msksp.2017.04.006.
  3. Serner A, Tol JL, Jomaah N, et al. Diagnosis of Acute Groin Injuries. The American Journal of Sports Medicine. 2015;43(8):1857-1864. doi:10.1177/0363546515585123.
  4. Tyler TF, Silvers HJ, Gerhardt MB, Nicholas SJ. Groin Injuries in Sports Medicine. Sports Health. 2010;2(3):231-236. doi:10.1177/1941738110366820.