Anatomy and Stretching 101
The posterior compartment of the thigh “Hamstrings” The hamstrings received their name because it is common to tie hams (pork thighs) up for curing and/or smoking with a hook around these muscle tendons. This also explains the expression “hamstringing the enemy” by slashing these tendons lateral and medial to the knees.
The Anatomy • The muscles in the posterior compartment of the thigh are hamstrings. • The hamstrings are separated from the anterior compartment of the thigh by the lateral intermuscular septum. • Deep to the hamstrings on the posterior thigh is the adductor magnus, which is also separated from the posterior compartment by deep fascia. • The hamstring muscles are:1) semitendinosus, 2) semimembranosus and 3) biceps femoris (long head). See Image A.
The hamstring muscles have common features: • Proximal attachment to the ischial tuberosity deep to the gluteus maximus • Distal attachment to the bones of the leg • The hamstrings span and act on two joints, producing extension at the hip joint and flexion at the knee joint. • The short head of the biceps femoris, although a part of the posterior compartment, arises from the lateral lip of the inferior third of the linea aspera and supra condylar ridge of the femur.
IMAGE A
The two actions of the hamstrings cannot be performed maximally at the same time: full flexion of the knee requires so much shortening of the hamstrings that they cannot provide the additional contraction that would be necessary for simultaneous full extension of the thigh; similarly, full extension of the hip shortens the hamstrings so they cannot further contract to act fully on the knee. (Another example of active insufficiency.) When the thighs and legs are fixed, the hamstrings can help extend the trunk at the hip joint. They are active in thigh extension under all situations including maintenance of the relaxed standing posture (standing at ease).
A person with paralysed hamstrings tends to fall forward because the gluteus maximus muscles cannot maintain the necessary muscle tone to stand straight. The hamstrings are the hip extensors involved in walking on flat ground, when the gluteus maximus demonstrates minimal activity. During normal walking, the hamstrings demonstrate most activity when they are eccentrically contracting,resisting (decelerating) hip flexion and knee extension during terminal swing (between mid-swing and heel strike).
Bicep Femoris The fusiform bicep femoris, as its name indicates, has two heads: a long head (Image B) and a short head (see Image C). In the inferior part of the thigh, the long head becomes tendinous and is joined by the short head. The rounded common tendon of these heads attaches to the head of the fibula and can easily be seen and felt as it passes the knee, especially when the knee is flexed against resistance. The short head of the biceps femoris arises from the lateral lip of the inferior third of the linea aspera and supracondylar ridge of the femur (Image C). Whereas the hamstrings have a common nerve supply from the tibial division of the sciatic nerve, the short head of the biceps is innervated by the fibular division. Because each of the two heads of the biceps femoris has a different nerve supply, a wound in the posterior thigh with nerve injury may paralyse one head and not the other.
IMAGE B
Image B. Long head of Biceps femoris
IMAGE C
Image C. Short head of Biceps femoris
When the knee is flexed to 90°, the tendons of the lateral hamstrings (biceps), as well as the iliotibial tract, pass to the lateral side of the tibia. In this position, contraction of the biceps and tensor fasciae latae produces about 40° lateral rotation of the tibia at the knee. Image D. Rotation of the flexed knee is especially important for example in snow skiing and changing directions rapidly during running.
IMAGE D
Image D. The short and long heads of bicpes can externally rotate the tibia with the knee flexed.
IMAGE E
Semitendinosus The semitendinosus, as its name indicated, is half tendinous (Image E). It has a fusiform belly that is usually interrupted by a tendinous intersection and a long, cordlike tendon that begins approximately two thirds of the way down the thigh. Distally, the tendon attaches to the medial surface of the superior part of the tibia as part of the pes anserinus formation in conjunction with the tendinous insertions of the sartorius and gracilis.
Semimembranosus
IMAGE F
The semimembranosus is a broad muscle that is also aptly named because of the flattened membranous form of its proximal attachment to the ischial tuberosity (Image F). The tendon of the semimembranosus forms around the middle of the thigh and descends to the posterior part of the medial condyle of the tibia. When the knee is flexed to 90°, the tendons of the medial hamstrings or “semi-“muscles (semitendinosus and semimembranosus) pass to the medial side of the tibia. In this position, contraction of the medial hamstrings (and of synergists including the gracilis, sartorius, and popliteus) produces a limited amount (about 10-25 degrees) of medial rotation of the tibia at the knee. Image G.
IMAGE G
Image G. Semitendinosus, along with sartorius, gracilis and semimembranosus internally rotates the tibia.
Stretching The hamstrings are stretched by reversing their primary actions i.e by flexing the hip and extending the knee. Some stretching can be effective by producing strong hip flexion with a bent knee, but the sensations are more likely from the posterior head of adductor magnus and gluteus maximus. Explore the stretches below for 2 to 3 minutes each. A large muscle group requires considerable time under tension to trigger growth and adaptation.
Straight Leg Versions / Lying HS • Standard: Beginner & Intermediate • Spring Tension: Medium • Muscle Emphasis: HS group, gastrocnemius, adductor magnus, horizontal leg-hip flexors
A
A & B. How to stretch
Place foot in strap. Take straight leg up to POT very slowly. Hold for 5 breaths
How to contract Pull entire leg back down toward floor OR try to bend knee. Hold for 5 seconds.
B
B. How to restretch On a breath out, allow carriage to slide in and hip to flex further.
What to watch out for: • Legs remain parallel. • Hips remain square to leg/ neutral pelvis, no posterior or lateral rotation. • Legs remain straight. • Bottom leg remains horizontal.
The Standing Straight Leg Hamstrings • Standard: Beginner - Intermediate • Spring Tension: Light - Medium • Muscle Emphasis: Hamstrings, gastrocnemius, tibialis anterior, rear leg hip flexors
A
A. How to stretch Keep legs in line with sit bones. Press rear leg back to level hips; i.e. parallel (ensure two ASIS are level). Press carriage away/lean hips back to POT.
B
B. How to contract Press front foot into floor.
C. How to restretch Slide carriage further from resting position.
C
What to watch out for: • Spine or low back flattening/rounding. • Lateral pelvic rotation toward front leg. • Front knee bending. • Pelvis must remain neutral or anterior tilt. • Hips to remain square to line of legs.
Foam Roller Hamstring HOW TO STRETCH: Photo A - Sit as pictured and pull chest towards thighs - Slowly straighten legs keeping chest in contact with thighs HOW TO CONTRACT: Photo A - Press the ankles or feet down into the roller
FOR THE SPINE: Photo C - Allow back to bend/flex, pull chest closer to legs
C
A
HOW TO RESTRETCH: Photo B - Straighten the legs further, keeping chest on legs HOW TO INTENSIFY: Photo B - Bend toes further backwards - Lift chest to straighten spine
B
Major muscles stretched Erector spinae Hamstrings Calves Adductor magnus Gluteus maximus
Hamstring Glute Partner HOW TO STRETCH: Photo A - Lie as pictured, with partner using straight arms to move and support you - Pull one leg back towards your chest or armpit and hook arm around hamstrings - Partner leans towards you, opening out angle at your knee joint - do not allow thigh to creep away from chest HOW TO CONTRACT: Photo B - Press thigh away from chest while simultaneously pressing heel towards bottom
A
HOW TO RESTRETCH: Photo B - Pull thigh as close as possible to chest or armpit and open the ankle further at the knee joint
B
Major muscles stretched Gluteus maximus Hamstrings Adductor magnus Rectus femoris TFL Iliopsoas
The Standing Straight Leg Hamstring • Standard: Any • Muscle Emphasis: Underside of front leg-hamstrings, calves, peroneals
A
B
A. How to stretch Place one foot forward,or in front of the slantboard, ensure hips level horizontally and square. Hold bars for maximum support, anterior pelvic tilt, lower trunk to POT.
B. How to contract Press stretching leg down and backwards in the “bullfighters” contraction.
C
C. How to restretch Lower trunk further, increase anterior tilt of pelvis.
What to watch out for: • Posterior pelvic rotation and spinal flexion.
• Hip losing alignment.
Bar Hamstrings • Standard: Intermediate to advanced • Muscle Emphasis: Entire hamstring group
A
A. How to stretch Place foot onto bar at approx. 90 degrees (lower for less intensity, higher for greater). Rotate pelvis to anterior tilt. Keep spine straight. Minimise dorsiflexion.
A. How to contract Press entire leg down into bar, or ‘Quarter circle'.
B
B. How to restretch Increase hip flexion with spine straight and anterior pelvic tilt.
Conclusion The stretches that require no equipment can be found in my book “StretchFit: Safe Effective Stretches for Every Body,” on Amazon books. The other stretches on the Pilates reformer is from “Stretching on the Pilates Reformer: Essential Cues and Images” on Amazon books.