Hamstring injuries are the source of much vexation in the exercise field. While the human body and human movement are extraordinarily complex, and a person may possess some unique characteristics that require puzzle solving, I believe the vast majority of hamstring injuries are preventable through simple interventions…

The following posts from IG explain the reasoning behind these simple solutions.

View this post on Instagram

HAMSTRINGS part 5. Hamstring length. Some sport actions like hurdling and following through after a kick should feature hamstring flexibility. Regular sprint mechanics should NOT… BUT all athletes should still have long hamstrings. Why? Greater muscle fascicle length (FL)… •decreases injury risk •increases contraction velocity. ———— If you know your muscle cell anatomy this should make sense, but let’s look at some large scale research. Study titles will be in comments. •SLIDE 1: 152 soccer players did pre-season hamstring testing, and then injuries during the season were recorded. Shout out to @ylmsportscience for the info-graphic. It shows clearly that short hamstring fascicles and weakness increased injury risk. FL under 10.56cm multiplied injury risk by 4.1. •SLIDE 2: Athletic performance is impacted by many variables, so you can’t expect just one to always yield the right correlation. But a few studies show greater FL in the quads and calves actually does correlate to faster 100m times, even within a population of sprinters. •SLIDE 3: The impact of FL is even more clear when comparing sprinters to distance runners or non-athletes. ———— So we definitely want greater FL, but here’s where it gets tricky. FL and flexibility/range of motion are not the same thing. FL measures the contractile protein in the muscle, but there is much more to a muscle-tendon unit than just protein. Data shows that stretching clearly increases ROM dramatically but not necessarily FL. Some training can increase FL, but maybe not ROM. So do we actually need hamstring flexibility? Or can we just train to increase FL? One study (slide 4) did show correlation between flexibility and lower injury rates, but this is not really the overall consensus of the research. Hmm… more to come.

A post shared by @ jump_science on

View this post on Instagram

HAMSTRINGS part 6. Research shows a variety of training can increase strength and fascicle length at a low level when compared to no training. But how do we get to a high level over time? We need to strength train with range of motion. (Swipe for research evidence.) To do that, we need ROM available. ——— Can we simply strength train to get ROM? In my experience, not with the hamstrings. Stretching them with hip hinges for 3-4 sets twice per week does not improve ROM. Perhaps doing it every day would get the job done. But it’s more reasonable to stretch thoroughly every day, which typically improves ROM within days. Stretching is not in vogue in the exercise field, but it remains the best way to improve range of motion. Still more to come on hamstring strength.

A post shared by @ jump_science on

Along with all the research there is plenty of experiential evidence to support this approach as well. A couple examples…

It´s Douglas here again, the Decathlete from Sweden. First of all i just want to say that the last video you send to me about stiff deadlifts have been a real success for me. I have had muscle strains in the hamstring like 10 times in my career before and it sucks but the last year has been No pain at all! So thank you so much for your videos!

That being said we do have to acknowledge the nordic hamstring curl.

View this post on Instagram

HAMSTRINGS part 8. Do we need to train knee flexion strength? Consider separately neurological and structural characteristics. ———— Knee flexion does not drive athletic movement. It controls the lower leg during the swing phase of various activity. It’s low load, high velocity, submaximal effort movement. Slow, heavy knee flexion strength is not relevant neurologically. Training the brain to direct tons of neural drive into knee flexion is not meaningful. (Unless maybe you’re hanging from something by your feet?) ———— Structurally speaking, the nordic curl (the best knee flexion exercise) can feature extremely high targeted hamstring effort and eccentric overload, two factors that create high muscle tension. What nordics lack compared to hip hinges is muscle length, which makes hip hinges a generally superior structural exercise. However two reasons why nordics are probably still worth doing… 1. The short head of the biceps femoris only crosses the knee, so it can only be trained by knee flexion. 2. Variety in loading probably has value structurally. ———— Also nordics have been shown to be highly effective compared to no direct hamstring work, so if you can’t do hip hinges please do these. . . #JumpScience #hamstrings #injuryprevention #strength #football #soccer #track #trackandfield #speed #speedtraining #tracknation #longjump #triplejump #100m #pt

A post shared by @ jump_science on

When discussing hamstring training, another thing that needs to be mentioned is that the hamstrings are a critical muscle for ACL injury risk reduction. All muscles that cross the knee joint help to stabilize it. The hamstrings should be the strongest of these muscles. They are also positioned to prevent forward movement of the tibia relative to the femur. Considering ACL protection, do we need to train the hamstrings in a special way? See below.

Please do your hip hinges!