By Adam Bisek


The Hamstrings are composed of 3 distinct muscles: Biceps Femoris (short and long heads), Semitendinosus, and Semimembranosus. The long head of the Biceps Femoris, Semitendinosus, and Semimembranosus all share a common origin point at the ischial tuberosity of the pelvis. However, the long head of the biceps (and short head) insert at the fibula while the Semitendinosus and Semimembranosus insert at the tibia. Visually, the Biceps Femoris (the long head laying over the top of the smaller short head that originates on the femur) sits most lateral (outside) of the leg, moving inward (medially) towards the center of the body next is the Semitendinosus, and then closest to the centerline of the body is the Semimembranosus.


While all 3 muscles of the hamstrings group share similar functions there are some distinct differences in their contributions to movement based on their location and boney attachments.

Biceps Femoris: The long head flexes the knee joint as seen in a leg curl, extends the hip/thigh in movements like deadlifts, but also laterally (outwardly) rotates the lower leg. The short head does not extend the hip as it attaches to the femur and only acts on the lower leg, flexing the knee and laterally rotating the lower leg.

Semitendinosus/Semimembranosus: Both of these muscles extend the hip/thigh, flex the knee, and inwardly (medially) rotate the lower leg.

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The Exercises

1) The Shortened Position: Hips Extended Lying Leg Curl

Working Sets: 3

Repetition Range: 10-12

Tempo: 2011

Rest: ~60-90

**RIR: ~1-2

Most gyms will have a lying leg curl, the flatter the pad you lay on the better. If the apparatus as a completely flat lying surface you’re already placed in a decently hips extended position. However, if your apparatus is angled to any large degree putting you into more hip flexion raising yourself off the pad by placing your elbows down may be a good option. If doing so make sure that you keep a really good, braced abdominal wall and do not allow arching (lumbar extension) or your lower back whatsoever.

Start by having your ankles/feet in a plantarflexed position (as if walking on your tiptoes) to shorten your gastrocnemius (calf muscle) and create something called active insufficiency of that muscle. Because the gastrocnemius helps in knee flexion putting it in an already fully shortened position severely lessens the degree to which it can help the hamstrings flex the knee, isolating the hamstrings muscle more in this movement. You will also want to press your hips into the pad, squeezing your glutes and bracing your abdominal wall. This posture is one you want to try and maintain the whole set. Doing so, along with the ankle position, really puts the hamstrings in a position where they are the only ones who can create purposeful movement.

Start the movement smoothly, don’t start with a jerk as many people do. In a controlled fashion drive your heels up imagining you’re curling your hamstrings similar to how you curl your biceps. This cue often helps people make a good connection through association. Hold the top end, shortened contraction for a second voluntarily squeezing as hard as you can to make a good connection with your hamstrings. Lower the weight back down under control and make a smooth transition back into your next repetition.

This movement puts the hamstrings in their shortest position, and while peak tension may not be in the absolute shortest position it's close. We are not trying to kill you on this movement but rather get blood into the target muscle and gain a really good connection to start the session.

2) The Mid-Range Position: Roman Chair Hip Extension (Hamstring Dominant)

Working Sets: 3-4

Repetition Range: 8-12

Tempo: 3010

Rest: ~60-90 seconds

RIR: ~0-1

Most people will have access to a roman chair, and if not Romanian or stiff-legged deadlift variations are decent swaps. The majority of roman chairs will be roughly 45 degrees, but any 10-15 degree variation from that is pretty negligible. With a 45 degree roman chair, this movement will exhibit maximal torques, or the most difficult part of the range of motion when the hamstrings are at about mid-length.

Start with your feet roughly hip-width apart and feet facing straight, not externally rotated. The thigh pad should be low enough to allow for you to fully flex over at the hip and the top of the pad a little lower than the boney protrusion of your hip (Anterior Superior Illiac Spine) to help bias the hamstrings. Before you start the movement create a little tension in your hamstrings by flexing your knee just a bit. Imagine starting a leg curl and the tension that would create. Just create a little bit of tension and flex your knee maybe 5% so your legs are not locked out straight. This will also help bias the hamstrings.

To take your lower back musculature out of the movement tuck your chin to your sternum and flex over your spine almost as if to do a complete crunch. Make sure to hold this position the entirety of the exercise. Now descend, flexing as far over at the hip as you can until you achieve a good stretch in your hamstrings. From the bottom reverse your movement by driving your heels/achilles against their respective pad as well as keeping a good amount of pressure pushing your knees/thighs into their respective pads. Make sure not to extend your back/spine as this will start to bring in extra musculature that we don’t want in this movement.

This movement targets the hamstrings in their function of extending the hip/thigh. This is our “lengthening” movement that compliments the other “shortening” or knee flexion-based movements of the OGS hamstrings model. Knowing this you can use other hamstring movements that accentuate their eccentric, hip extension action such as Romanian/stiff-legged deadlifts, good mornings, or GHD hip extensions.

3) The Lengthened Position: Hips Flexed Nordic Curl

*Alternate: Hips Flexed Seated Leg Curl

Working Sets: 3-4

Repetition Range: 6-8 (8-10)

Tempo: 4010 (3110)

Rest: ~90-120 seconds

RIR: ~0-1

This movement is our lengthened position movement and one that focuses on the knee flexion action of the hamstrings. Because of the availability of equipment and the ability of every individual I have put several options in place here: HF Nordic Curl on seated calf raise apparatus, HF Nordic Curl on GHD, and a HF Seated Leg Curl.

For the Hips Flexed Nordic Curl done on a Glute-Ham Developer (GHD) apparatus simply position yourself such that your ankle and knee will be roughly at the same height. As far as the distance to set between your feet and the knee/thigh pad that will depend on your ability level so you will have to experiment with the distance but you want to ensure you’re still hinging mainly at your knees. Start by getting into the right position, bending/flexing over at your hip such that you’re roughly making a 90-degree angle with your thighs and torso, this will make it so that you reach near full length of your hamstrings at the bottom position. Descend slowly and for the first repetition or two you will need to build into your full range and assess your “point of no return.” The goal is to be able to reach almost full extension of your knee, but I would advise again getting to full lockout extension as this is a massive amount of torque on the knee joint at the bottom range and putting that much torque on the soft tissues of the posterior side of the knee isn’t the best idea. From the bottom come back up by driving your heels/achilles against the top footpad and knees into the knee/thigh pad.

When using the seated calf raise apparatus to complete this movement a lot of the same set-up and movement cues are the same as above. However, because there is just a flat surface the movement will inherently be harder than the GHD variations that will often offer a more forgiving, rounded pad that can shorten the moment arm of the movement (make it easier). With this in mind understand that it’s even more important to abbreviate your initial reps and test out your range of motion capabilities. For many full range of motion will be too difficult and thus simply gaining more range of motion will be a dictator of progression session-to-session. In this case, having a box or something similar in front of you to catch yourself or temper your descent is advised.

The hips flexed seated leg curl is the most practical movement of the three from a logistical and physical capability standpoint. Using a standard seated leg curl apparatus simply sit forward off the seat a bit (flex over at the hip) maintaining good posture. Often holding on to the machine will be needed to keep this position. Also, point your toes into a plantarflexed position as if to be on your tiptoes. From here just make sure you note the tempo change for this variation (3110), a little faster lengthening/eccentric phase and a 1-second pause in the fully stretched position. Because this movement will not create the same high torques at the knee joint like the Nordic Curl will we are in a safer position to accentuate the stretched position. Now smoothly drive your heels back to get to the fully knee flexed position. In regards to a cue think of the one we used for the first leg curl variation of flexing your biceps brachii upper arm muscle, this often helps envision how to feel the shortened position of the hamstrings.


With the lion share of hamstring-based movements being categorized as single-joint, isolation exercises this OGS model will most likely not be a standalone training session. Unless your hamstrings are massively underdeveloped compared to your glutes and/or quads you most likely will be integrating these movements into a training session that has larger, multi-joint lower body exercises. However, that does not mean that you couldn’t do the three movements in sequence as laid out, it just means their implementation most likely, and practically, will be spread out within one or more sessions of the week.

Using the old school Weider Priority Principle, if your hamstrings happen to be your weak point then starting your session with them makes a whole lot of sense. Our OGS shortened position movement, the lying leg curl, makes a great initial movement to any lower body training session. This followed by 1-2 larger, multi-joint movements such as squats, lunges, leg presses, or even deadlift variations would be a pragmatic approach for most trainees. To follow these either one or both of the remaining 2 OGS hamstrings exercises makes sense. Remember, you don’t inherently have to complete the whole OGS model in one training session, but rather over a microcycle (1-week).

The total volume of our OGS hamstrings model is ~9-11 working sets, and thus if you want to make hamstrings a priority for growth and you’re a relatively experienced trainee you may need a bit more total weekly volume, but I wouldn’t go over 20-25 total working sets. It’s also important to consider the role of the hamstrings in other movements as well, especially deadlift variations or any leg press, squat, or lunge-based movement that involves far greater hip movement than knee movement as this will cause some hamstrings involvement. However, I do believe an additional, heavier hip extension-based movement and possibly knee flexion-based (leg curl) movement to bring up your total hamstrings volume if you’re emphasizing hamstrings growth primarily in your current phase of training.

*Tempo is referred to in a 4-digit sequence whereby the first digit and thirst digits are the lowering/lengthening (eccentric) contraction and raising/shortening (concentric) contraction respectively. The second and fourth digits are the times between those two contractions/movements. For example, using the Lying Leg Curl tempo above (2011) you would lower the weight and lengthen your hamstrings for 2 seconds (2011), not pause (2011), flex your legs/knees for 1 second (2011), and then hold that full flexed, shortened contraction for 1 second (2011) before lowering the weight again.

**RIR stands for Repetitions in Reserve and is essentially the assumed amount of repetitions you have left before you technically fail on the exercise. Technical failure is denoted by the last repetition you can complete with technically sounds failure, this is not absolute failure, where simply completing the repetition with breaks in form and compensation most often occurring.

Iso Poofs Link


Muscles in the Posterior Compartment of the Thigh. (n.d.). Retrieved from