Posts tagged hamstring strengthening
Nordic Hamstring Exercise Shown to More Evenly Recruit Hamstring Muscles
Photo Credit: Jospt.org

Photo Credit: Jospt.org

Hamstring injuries are a common sports medicine injury treated in our Boulder Physical Therapy practice.  These injuries can be placed in two categories: acute trauma often related to sprinting and cutting movements or repetitive stress and overload to the hamstring often found in athletes with weak gluteus muscles.  In our previous blog posts, we have described the importance of gradual loading of the injured hamstring to promote an optimal healing (remodeling) response, as well as, utilizing a hamstring strengthening program to reduce the risk of future hamstring injury.  A recent article sheds light on common exercises used to strengthen the hamstring and how these different exercises target the 3 muscles which make up the hamstring.

Messer and colleagues studied the hamstrings of active women without a history of lower limb injury (JOSPT. 2018).  All participants underwent a MRI both before and after performing eccentric (lengthening) contractions of the hamstrings on both of the exercises pictured above.  Muscle activation levels were calculated based on changes between the two MRI images.  The authors reported both exercises targeted the inner (medial) hamstring muscle, but the commonly utilized nordic hamstring exercise more evenly recruited all 3 hamstring muscles.    

Contact the experts at MEND to learn more on which exercises are best for your sports or orthopedic injury

 

Hamstring Training for Sprinters
hamstring-injury-strain-pain-sprinting

Sprinting either in track or sport requires rapid, high force muscle contractions across the lower body.  If the forces utilized during the acceleration phase of running are greater than the capacity of the muscle to absorb these forces injuries can occur.  Hamstring strains in this population of runners are common due to the rapid shortening and lengthening of the contracting muscles.  We have previously written on our Physical Therapy blog on the diagnosis and treatment of these injuries, but off season and in season strengthening remains the standard of care.  Specifically, nordic hamstring curls are often prescribed for sprinting athletes but a recent research article highlights other exercises which be used for hamstring strengthening among sprinters.

photo credit: International Journal of Sports Physical Therapy

photo credit: International Journal of Sports Physical Therapy

In the International Journal of Sports Physical Therapy authors studied healthy male participants as they sprinted and performed a variety of hamstring strengthening exercises (van den Tillaar et al. 2017).  The authors measured hamstring muscle recruitment and lower body biomechanics during each of these tasks to determine which Physical Therapy exercises best represent the muscular and biomechanical demands of sprinting.  The authors report the nordic hamstring curl, as well as, the laying kick activate the hamstring muscles at a high enough level and similar joint angle to benefit sprinters' strength training programs. 

To learn more on which exercises are best for your activity contact your local Physical Therapist. 

Reducing Hamstring Strains in Sprinters
hamstring-injury-pull-strain-sprinting

Hamstring strains or pulls are a common injury among acceleration sports including rugby, soccer, and sprinting.  Our previous blogs have written about the causes and treatments of these muscle injuries.  One of the common causes of injury involves a lengthening contraction (eccentric) of the muscle during these explosive sports movements.  If the muscle is unable to handle the forces placed upon it an injury occurs.  To reduce this injury risk, researchers and clinicians have focused on improved the strength and tissue capacity of the hamstring through training.  

A long term study was reported in the Orthopedic Journal of Sports Medicine describing 3 different interventions utilized to reduce the risk of hamstring injury (Sugiura et al. 2017).  Authors assessed 3 different prevention methods in a group of top ranked collegiate and national level sprinters over a 24 year period.  The first training program utilized over a 4 year period consisted of strengthening on a leg curl machine.  During this period 16 strain injuries occurred in a group of 116 sprinters.  The staff then included hip strengthening, agility and hurdle work in addition to the leg curl.  The authors reported a 56% reduction in hamstring strains over this 9 year period.  Finally, the authors included exercises from the first two interventions as well as dynamic stretches and nordic curl training for the hamstring.  This group of close to 300 sprinters sustained only 2 strain injuries over a 12 year period, almost a 90% reduction in strain rates.  

Courtesy: bretcontreras.com

Courtesy: bretcontreras.com

This study adds to our existing evidence on the importance of of hamstring strengthening for both performance and injury prevention among sprinting athletes 

Maximizing Hamstring Recruitment During Exercise

The hamstrings are an essential component of the posterior chain of muscles stabilizing our back and legs.  Despite the hamstring's importance, length, and strength production they remain a commonly injured muscle seen in our Boulder Physical Therapy practice.  Our previous post described the importance of using different exercises to target the top and bottom portions of the muscle but additional research shows the impact of machine vs. free weight exercises. 

Zebis and colleagues studied healthy volunteers to determine the relative contribution of the 3 hamstring muscles during commonly utilized strengthening exercises (Br J Sp Med. 2012).  Many exercises recruited the inside and outside hamstring muscles evenly including nordic hamstring curls, hamstring curls on a ball, and seated machine leg curls.  Two exercises targeted the 2 inside hamstring muscles more than the outside including a kettlebell swing and the romanian deadlift.  Conversely, horizontal back extensions against gravity and horizontal machine leg curls recruited the outside more than the inside hamstrings.