Continuing with our stretch series from the ground up, we come to the hamstrings stretch.
The hamstrings muscle forms the bulk of the muscle on the back of the thigh. It is made up of 3 muscles, namely the Semitendinosus, the Semimembranosus and the Biceps Femoris.
• The semitendinosus, semimembranosus and biceps femoris long head, all originate from the ischial tuberosity or the “sit bone.”
• Biceps femoris short head originates from the femur (thigh bone) from a prominent line called the linea aspera and the outer femoral condyle.
• As the name implies, the ischial tuberosity is the prominent bony projection of the pelvic bone named ischium (pelvis is formed on each side by the fusion of ilium, ischium and pubis bones).
• The Semitendinosus and Semimembranosus insert into the upper medial (inner side of leg) part of the tibial bone. The Semitendinosus with 2 other muscles (Sartorius and Gracilis) forms 1 of the 3 prongs of the duck/goose foot called the “pes anserinus.”
• The biceps femoris inserts on the fibular head (lateral or outer side of leg).
The hamstring muscle is a two-joint muscle (except the short head of biceps which crosses behind the knee joint only) and crosses behind the hip joint and the knee joint. The contraction of this muscle extends the hip joint and flexes the knee joint, therefore it stretches when the hip flexes with knee extension. It is prone to injury through overuse and strain including sudden athletic injuries playing various sports involving running or jumping.
The various ways to stretch this muscle are: (for ease of understanding let us consider stretching of the right hamstrings in all the one-sided stretch positions)
1) Passive stretch: The patient /client lies in supine (facing up) position. The therapist or trained person lifts the right leg by flexing the hip and knee to 90-90 degrees. Then gently straightens the knee joint till a stretch is felt along the back of the thigh. The left leg should be resting on mat/floor in neutral position with a straight knee.
2) Active static stretch:
i) This is done in supine position with the trunk supported and stable with pelvis resting on the floor/mat/bed. The left leg is in neutral resting on mat. Start by bending the right leg at hip and knee to bring it to 90-90 position as in above stretch. Hold the right thigh with both hands, just below the knee joint. Slowly, extend the right knee and straighten the leg as far as possible making sure the pelvis and hip is stable. A stretch is felt behind the thigh in the hamstrings muscle. Hold the stretch for as long as possible from 5 seconds to 30 seconds. Release the position by bending the knee and rest for 15-30 seconds. Repeat stretch 2-3 times.
ii) Start in the long sitting position and reach for the toes to stretch the hamstrings while keeping the knee stable and resting on the floor while you move forward at the hip, flexing and stretching the muscle proximally at hip joint. Another way is to hold the feet with both hands by flexing the hip and knee, then slowly extending the hip and knee lowering the leg to the floor, while maintaining trunk position. This method keeps the proximal end stable and stretches the muscle/tendon distally, near the knee joint.
3) Active dynamic stretch: Some of the daily activities put this muscle in stretch position as in forward bending. A lot of the yoga asanas such as the mountain pose (parvatasana), triangle pose (Uthitta Trikonasana), forward bending head-to-knee pose (Janu sirshasana) are aimed at stretching the hamstrings.
i) Mountain pose: Here both the hamstring muscles are stretched simultaneously. Begin in the quadruped position on a mat and bring the sole of feet to the floor by straightening knees and lifting the pelvis towards ceiling. Bring the head between the arms while gaze is fixed on knees, forming an inverted “V.” Hold the position while inhaling and exhaling completely, you can build up to multiple breath cycles.
ii) Triangle pose: Stand with a wide stance feet pointing forward and knees straight with an upright, neutral trunk. Turn the right leg out 90 degrees at hip, so that toes are pointing to the right. Bring both arms up at shoulder level, head turned right, elbows straight, fingers straight, palms open and facing floor, gaze fixed on right thumb. Slowly lower trunk to right by bending at right hip joint and bring the right hand to the right shin. Slide the hand down the shin and bring fingers/hand to the ankle and possibly the floor. For final pose, open up at the chest by bringing the left arm up toward ceiling and rotating head to left for gazing at the left hand now. Hold the pose for 5 seconds to 30 seconds. Release by slowly bringing torso upright and rest for 15-30 seconds. Repeat 2-3 times.
iii) Janu sirshasana: Sit up in staff pose or long-sitting position with palms on floor slightly behind the pelvis. Bend the left leg at hip and knee and place sole of left foot along the inner right thigh. Raise both arms up towards ceiling, elongating the spine and reach forward by bending at hip (torso is elongated throughout with minimal rounding of spine at the end of pose). With both hands hold the shin of right leg and slide down during the exhalation in breath cycle to deepen the pose for further stretch of the posterior chain tissue (including hamstrings). Take a deep breath in and hold position and slide hands further down at the next exhalation till you reach end position. You work towards being able to bring the head to right knee, with the knee straight and hands around the sole of right foot. Release pose slowly by raising torso to upright and bending the right knee. Repeat 2-3 times.
4) Stretch using tools or equipment:
i) Sit upright on chair with a neutral spine and right knee extended with the foot supported on a stool in front. The left foot is resting on the floor. Keeping the right knee straight, reach forward by bending at hip joints and sliding hands along the right thigh down towards the shin. Spine/trunk should be elongated throughout. Hold for 5- 30 seconds, release and rest for 15-30 seconds. Repeat 2-3 times.
ii) Lie on mat/floor with one end of a strap or gait belt looped around the right foot. Keeping left leg in neutral on the floor bring the right leg to 90-90 degree hip-knee flexion. Then holding the loose end of the strap in both hands, pull while extending the knee for stretch behind the thigh. Hold for 5 seconds to 30 seconds for as long as possible, release and rest 15-30 seconds. Repeat 2-3 times.
iii) Foam roll stretch: place a firm foam roll on mat or on the floor. Sit with sit bones on the roll with both legs extended at knee joints. Bring both hands with palms on floor behind the foam roll. Bend the left leg bringing the foot to the floor in front of the foam roll. Gently roll the foam roller under body weight back and forth along the back of right thigh from the sit bone to knee joint. This being a long muscle, you can begin from the sit bone (proximally) and roll 2-3 inch segments of the muscle at a time, then move distally.
Let us begin the series on stretching from the ground upwards. One of the most common stretches in the lower extremity is the calf stretch or the Achilles tendon stretch.
The Achilles tendon is made up of the gastrocnemius and soleus muscles, as they form a common tendon that inserts into the heel bone or calcaneus.
• The gastrocnemius originates from the femoral condyles (medial and lateral heads) above the knee joint.
• The soleus originates from below the knee joint, the fibular head and upper quarter of fibula bone, from the medial surface of tibia and parts of anterior muscular septum.
• As the muscles progress to the heel bone, they transition histologically into anterior and posterior aponeurosis, which are whitish, flat broad tendon-like structures.
• Eventually the aponeuroses transform to the tendon which inserts into the heel bone.
The different ways to stretch the muscle are as follows:
1) Passive stretch: here the patient/client is in supine-lying on a mat or is in long sitting position. The physical therapist stabilizes the neutral knee with one arm and the other arm cups the heel with the therapist forearm supporting the sole of the foot. The distal arm is slightly extended at the wrist for ergonomic grip and with the body movement moves the foot upwards with the forearm to dorsiflex the foot. It is important to get an end-feel of the soft tissue stretching and hence a slow, gentle stretch is essential initially to determine the stretch force to be applied for optimal results.
2) Active static stretch- The patient/client is in supine-lying on a mat or in long sitting position with the knee in neutral position and well supported. The patient keeps the knee and leg stable and dorsiflexes the foot with the calf-muscle being stretched by pointing the toes upwards in the direction of the face/nose (“toes to nose” as it is popularly addressed), till a stretch is felt in the back of the lower leg or calf. This position is held for as long as possible from 5 seconds up to 30 seconds. Release stretch and rest the muscle for 15-30 seconds and repeat 2-3 times.
3) Active dynamic stretch- There are several ways to do this. For example to stretch the right calf:
i) The patient/client is in half-kneeling position. The right foot is in front, resting on the floor, with knee and shin of the left leg resting on the floor. With the trunk upright and neutral, stabilize it as you flex the hip and knee of the right leg. The foot should be flat and firmly rooted to the floor as the body weight shifts onto the leg. This brings about dorsiflexion of the right foot, as the tibia/lower leg moves forward over a stationary foot on the floor, stretching the soleus primarily.
ii) In standing position, with the right foot behind and toes pointing forward both feet, lean forward from the ankles, keeping the right knee straight. This can be done while facing a wall. The left leg must allow hip and knee flexion as body weight (body moves as one unit from ankle up) moves forward maintaining a firmly planted right foot behind with the heel on the floor. It is ok to lean forward and rest the open palms on the wall.
iii) Another way to stretch the right calf in standing is to stand facing a wall. Bring the right foot and place the ball of foot on wall with the heel on the floor. Make sure to move the ball of foot as far up as you can by inching it upward along the wall, with the heel still on floor. Lean forward towards the wall deepening the stretch at the calf.
4) Stretching with tools or equipment:
i) Stretch using a strap or thera- band- in the long sitting position, loop a long strap or sturdy thera-band around the sole from mid-foot to ball of foot. Hold the two ends of the strap/band in hands. Gradually pull up the strap, thus dorsiflexing the foot and stretching the calf muscles.
ii) When seated on a chair with hip knee flexion and left foot on floor, you can use rocker board placed on floor with right foot on it and push the right heel to floor, thus tilting the rocker board up and dorsiflexing the right foot.
I will broach the topic of stretching in detail and then eventually take up specific muscle stretches over the upcoming weeks.
In my post on stretches on September 2nd, 2016, I mentioned stretches can be either “informal/ spontaneous” or “deliberate.” In physical therapy, we are concerned with deliberate stretches with a goal in mind. Stretches lead to increased flexibility of soft tissue. Though it is widely thought that it is a muscle being stretched, there are a lot many tissues in addition that are stretching (like fascia, nerves, blood vessels and connective tissue), to allow increase in flexibility or mobility at a given joint. The tensile strength of various tissues varies based on their elastic property, muscles, being the most flexible and elastic amongst these. It is important to realize, just as the tissues have varying properties and abilities, so do we. And while 10 degrees of motion for one allows him to work happily, doing what needs to be done in the course of the day, for another, 20 degrees may be required to achieve smooth execution of daily activities. Whatever is your requirement, with the above in mind, go slow with stretches, do multiple repetitions with holds and enjoy! Yes, you read that right, ENJOY! Stretches do not have to be painful or cause soreness. With the right effort and willingness, they can be an enjoyable activity. As long as you are doing what you need to, happily, no aches and pains associated due to tightness or stiffness, you are doing good.
The mechanism for muscle stretch can be seen from physiological or biomechanical perspective. Some of these are:
• Local stretch reflex acclimatization- The local stretch reflex is a mono-synaptic reflex and is hence a very quick response to muscle being stretched. The muscle spindle in muscle sends signal to spinal cord, which then sends response signal causing the stretched muscle to tighten or contract to prevent overstretch or sudden tear. So it is a primitive, protective mechanism. When the stretch is gradual and prolonged, the muscle spindle gets “acclimatized” to stretch and decreases the firing intensity, thus allowing the muscle to be stretched further.
• Reciprocal inhibition- Muscles around a joint exist in an agonist/antagonist relation. When the agonist muscle contracts, the antagonist muscle relaxes to allow movement to occur at the given joint. This is a primitive spinal cord reflex as well.
• For example the quadriceps (quads) and hamstrings (hams) at the knee are in such a relationship. When the quads contracts, the hamstrings relaxes to allow the knee joint to straighten. While stretching the hamstrings, when quads are engaged at end of stretch, it allows deepening of stretch through reciprocal inhibition of hamstrings.
• Proprioceptive neuro-muscular facilitation (PNF) - this is a technique in which brief contraction of muscle being stretched (at end of stretch) increases tension in muscle tendon junction where Golgi tendon organ is situated. The Golgi tendon organ (senses tension in muscle) sends signal to stretched muscle to relax with resulting slack (like a circuit-breaker) in muscle and thus facilitates voluntary deeper stretch.
Stretches can be done in various ways:
1) Passive: when a muscle stretch is done by your therapist or anyone else trained to do so, and you are doing nothing, such a stretch is passive. This stretch may be used to demonstrate what a muscle being stretched feels like so that you experience the right stretch. Sometimes, it may not be possible for you to stretch, as in after surgery or your doctor may want you to have a passive stretch. During passive stretch, holding gentle prolonged stretch and deepening the stretch gradually over 30 seconds to 2-3 minutes, increases efficacy of stretch by causing the local stretch reflex to decrease intensity due to acclimatization. Think of it as a learning phase, wherein the right experience increases awareness. For example a passive hamstrings stretch.
2) Active stretch: here you are putting in some muscular effort to bring about a stretch. During active stretch, acclimatization of the local stretch reflex as well reciprocal inhibition or PNF can be employed to deepen the stretch. Active stretch can be:
i) Static, wherein most your body is well supported and by holding one end of muscle insertion stable or steady, you are stretching the soft tissue by moving the other end of muscle insertion away. The focus here is on the tissue being stretched. Think of it as a skilled single-task performance. For example, a static hamstrings stretch in supine position.
ii) Dynamic, wherein you are in a posture simulating the lacking activity or any activity which demands the additional flexibility and it involves movement of the joints which the muscle crosses, while maintaining stability in other joints and postural balance. Think of it as a skilled multi-task performance. For example, a forward lunge, hip flexor stretch on floor/mat.
3) Stretching with use of tools: These are self-myofascial release techniques using tools like the foam roller, tennis balls, thera-belt, thera-cane, and so-on. Think of it as a person skilled in the tools of trade with ability to employ tools successfully for desired outcome. For example, IT band stretch on foam roller.
Moving upwards or from ground up in our gait consideration of body segments and their role while walking, this week calls for detailed look of the trunk. The trunk appears very stable with relatively less movement during the gait cycle, and so it appears that the trunk is less active, however this is not the case. The noteworthy activity in the major trunk muscles in harmony with the lower extremity muscles is responsible for the appearance of subtle movement and evident stability.
The last post mentioned that the pelvic bone is made up of three bones which are fused together. Namely the ilium, ischium and pubis bones. In the channel of weight transfer, the spine is closely linked to the pelvis for continuity. The sacrum which is the lower part of the spine is made of five fused vertebrae and it forms a very stable and well supported joint (supported by muscles and ligaments) with the pelvis(ilium) and hence is known as the sacro-iliac joint or SI joint. The weight transfers from the spine to the pelvis via sacrum to ilium and from pelvis to femur (lower extremity) via the hip joint.
Here it is important to mention two regions of the skeletal system-namely the lumbo-pelvic region (lumbar spine is highly mobile) and the pelvic-hip region (femur at hip joint is highly mobile). The strong muscular and ligamentous support in these regions are key to stability during weight transfer in the gait cycle. The former allows the weight transfer from a stable spine to the pelvis and the latter from the pelvis to the stable lower extremities. When you go to the physical therapist and are working on your core, it mainly concerns the stability in these two regions through the integrity of the supporting ligaments and strength of the surrounding musculature. See how it is all connected so immaculately?
We have considered the major muscles of the trunk and hip in earlier posts and I will refresh those briefly:
1) Abdominals- rectus abdominus, internal and external obliques and transversus abdominus
2) Back Extensors- multifidi and semispinalis and extensor spinae
3) The hip extensors- 3 gluteii which extend and rotate the hip and proximal hamstrings
4) Hip flexors- iliacus, psoas, rectus femoris, sartorius, gracilis, pectineus
5) Hip adductors- adductor magnus, adductor longus and adductor brevis
6) Hip abductors- Gluteus maximus, gluteus medius and gluteus minimus and Tensor Fascia Lata
There is motion of the trunk and pelvis in 3 major planes which I have considered in detail in an earlier post. They are:
1) Transverse plane which is parallel to the ground (forward and backward rotation of pelvis happen in this plane along a vertical axis)
2) Sagittal plane which divides the body into left and right halves (anterior and posterior pelvic tilt happens in this plane) and
3) Coronal plane which divides the body into front and back (lateral tilting of pelvis happens in this plane)
Now let us consider the pelvic and trunk movement and muscle work during the gait cycle.
• In the transverse plane: at right heel strike, the ipsilateral (same-sided) pelvis is forward in the transverse plane along a vertical axis in the direction of progression. The trunk, however, in order to conserve energy and for maximal efficiency, must stay facing in direction of progression and not follow the right leg. That is the trunk rotates to the left or swing side during single leg support and then comes to neutral at right leg mid-stance, then it rotates to right side, till the next right single leg support. That is, muscle contraction from right(ipsilateral) back extensors keep the spine upright and in direction of progression while the bilateral obliques co-contract as do the transverse abdominus and multifidi for stability. The passive left arm swing occurs in response to momentum generated and it contributes to keep the upper trunk from rotating towards the right (weight bearing) limb.
• In the sagittal plane: The gluteus maximus and ilio-psoas maintain pelvic stability, as the hip flexes and extends at heel strike and push-off, respectively. The pelvis posteriorly rotates at heel strike, then goes to anterior tilt quickly and slowly returns to posterior tilt again for next heel strike.
• In the Coronal plane: at right heel strike, with impact, there is lateral trunk flexion to the right. The gluteus medius on right contracts as left leg goes into swing phase, thus preventing the pelvis from dropping excessively laterally towards the left side when the left foot is off the ground (swing phase). Although there is a mild list of pelvis to swing leg in order to keep the COG from rising excessively.
As we know, the center of gravity moves in a figure of eight pattern “∞.” This means that it rises and drops vertically as it progresses forward. Gait is efficient with least movement of the COG. At early and late stance, it drops towards the ground and is at the highest during the mid-stance phase of each leg. All this muscle work just ensures, the vertebral column stays stable in as near neutral as possible and gets a ride over the mobile lower extremities, thus conserving energy.
Going back to gait this week, the earlier 2 posts on gait covered 1) the gait cycle and phases and 2) the role of the foot during gait. This week let us look at the role of the hip and knee joints and the rest of the lower limbs.
The lower extremities are made of the thigh which is the femur bone and lower leg which is a syndesmoses (immovable joint connected with connective tissue) of the tibia and fibula along with all the muscles and ligaments and the soft tissue which includes the blood vessels, nervous tissue, and fascia.
The hip joint is formed by the head of femur with the cup shaped acetabulum formed by fusion of the three pelvic bones (namely the ilium, ischium and pubis). The acetabulum is deep and is further deepened by a cartilage called the acetabular rim. This gives the hip joint a great deal of stability as is needed by a weight bearing joint. The lower end of the femur is made up of two condyles (round protuberance of bones) which is received by the shallow concavity of the “tibial plateau.” This is the knee joint. Here again the articular or joint surface of the tibia (tibial plateau) is deepened by articular cartilages. These are the menisci - two in number and called the medial meniscus and lateral meniscus- based on their position. The menisci form the weight bearing surface of the knee joint. When we walk, there is simultaneous mobility and weight bearing at the knee joint, which makes it important for menisci to have some mobility so as not to get trapped within the joint during time of weight transfer or impact (running, jumping), since its major role is to deepen the sockets and provide cushioning effect or shock absorption and even distribution of the weight. Both the hip joint and knee joint function and stability are enhanced due to the presence of muscles and ligaments. The buttock is made of the 3 gluteii muscles (maximus, medius, and minimus). The hip flexors like iliacus, psoas, sartorius, and rectus femoris pass through the groin area. The major muscle that forms the bulk of the anterior thigh is the quadriceps. It ends in a tendon which crosses the knee joint in front and within which is embedded the knee cap or patella. The role of the knee cap is to increase the efficiency of the quadriceps. The main muscle at the back of the thigh is the Hamstrings. Both the quadriceps and hamstrings are made up of a group of muscles. The bulk of muscle in the calf or back of lower leg is Gastrocnemius and soleus. It inserts into the heel bone (calcaneum) of the foot and is responsible for the effective push-off. The front and sides of the lower leg consist of muscles that support the arches in the foot and produce necessary movement for weight transfer on foot.
Now let us consider the gait cycle. During the stance phase, the hip is flexed at heel strike and gradually moves to neutral position as body weight moves over a stable foot, and ends in hip extension (actually 10 degrees of “hyperextension”- this comes from lumbar extension) just prior to push-off, at which point it begins flexion together with knee flexion. The maximal hip flexion (30 degrees) occurs during the swing phase to enable the foot to leave contact with the ground and “sail across” space so that the body translates forward and “covers ground.”
The knee joint is in neutral or about 5 degrees of flexion at heel strike and it flexes slightly (15 degrees) in order to absorb the impact of initial contact with the ground and in preparation for weight bearing as the weight shifts to stance foot. This also brings stability by lowering the center of gravity of the body closer to the ground. The knee then gradually extends for joint stability at mid-stance for weight bearing and beginning of terminal stance when body progresses forward. At push-off (end of terminal stance), the knee flexes with the hip and attains about 60 degrees of flexion at peak swing, then begins relative extension towards heel strike.
At heel strike, the anterior tibial muscles are contracting to keep the foot in dorsiflexion and as they do so, it pulls the proximal end of the tibia forward, bringing the knee into flexion for shock absorption. The hip is stabilized and thrust forward by a strong contraction of the gluteus maximus and adductor magnus. The quadriceps begin to extend the knee and as the body progresses forward over a stable foot, the gluteus maximus contracts as weight bearing occurs at mid- stance and continues into terminal stance phase, progressing the body forwards. The iliacus and hamstrings bring about hip and knee flexion respectively for the push-off phase and swing phase. The limb then goes into deceleration as it prepares to go into the subsequent heel strike and the cycle continues seamlessly.
Ami Gandhi is a licensed physical therapist in the state of California. She is the owner of StableMovement Physical Therapy, a small boutique practice in San Jose that offers patient centered, one-on-one, hands-on physical therapy.