This is Dr. Richard Norris from the National Arts Medicine Center, and I'm going to be speaking today on medical problems and orthopedic considerations of cellists and bass players. First of all, in order to understand and prevent injuries, we have to understand what are the contributing factors. I have divided these somewhat arbitrarily into extrinsic, in other words, things that occur outside the body and intrinsic factors, things which occur within the body, with the understanding that this is a rather artificial distinction. The most common of the extrinsic contributing factors are abrupt changes, with emphasis on the word abrupt, changes in practice time or intensity. These too often occur most commonly during summer chamber music festivals or towards the end of a semester with juries and examinations coming up or for professionals at particularly busy times. Abrupt changes in teachers and instruments also require a decrease in the practice time and intensity in order to avoid overuse injuries. And it's not that one teacher's style is better than another's, but that if a teacher changes the way you bow or finger, you're going to be using your muscles differently and you need to back off a little bit. Also abrupt changes in instruments, if you switch from instruments that are different size or different quality, et cetera. In terms of the repertoire, we're going to go into this a little bit later, but there are some pieces and some styles of music that perhaps have an increased risk of injury with them. Instrument quality and size, particularly as it pertains to body size, is something important to note also. Cellos do come in various sizes and a person must try to make sure that the one that they have is suitable for them and comfortable to play and not just to have a cello because you like the sound or the quality of the instrument, although certainly that's important too. Inadequate rehabilitation of previous injuries is something that's often overlooked. The neck strain or back strain or tendonitis that's rested just until the person can go back to playing but that the pain still lingers on by Murphy's law is likely to flare up at the worst possible time. What constitutes adequate rehabilitation is full restoration of strength, flexibility, range of motion, strength, endurance, and coordination. Once those parameters have been fully reestablished, then rehabilitation can be considered to be complete. Also other hand intensive usage is important. Someone might have great technique and practice habits at the instrument, but develop overuse injury from typing on the computer or gardening or other hobbies that require hand intensive usage. So one must take care with this as well. Among the intrinsic factors, probably the most common is faulty technique. This was a typo on the slide, but I loved it so I left it in. It says faculty technique, which is a whole subject in and of itself. But regarding faulty technique, the most common ones are excessive force and either gripping the bow or pressing down on the strings or holding the instrument in an awkward or stressful posture. Also, psychological states such as stress often manifest themselves as increased muscular tension, which then predisposes towards muscular injuries. And while depression may not directly contribute to injury, if one is drinking too much, smoking, not eating properly, not sleeping well, not generally taking care of oneself, this has an impact on injury healing. General physical conditioning in terms of strength and flexibility certainly have a lot to do as far as posture goes and as far as injury prevention goes. If one has to play in an awkward position, the better general physical condition one is in, the less the risk of injury. Physical variations, especially things such as hand size and length of the arms, can play a relationship to injury as well. And finally, gender can be a factor. A study that was done by the International Conference of Symphony and Opera Musicians in about 1986 showed a higher incidence of overuse injuries in young females, especially the ones that played larger instruments such as cello and bass. And while the implications of this are not entirely clear and certainly shouldn't discourage women or young women from playing these instruments, it may mean that they need to pay more attention to things such as general physical conditioning, posture at the instrument, smart practice habits and the like. Moving on, this is Kato Havash who says a violin should be held tenderly. Don't do to this neck anything you wouldn't do to your own. The point being, use of excessive force in playing the instrument. Often we talk about the grip on the bow and gripping the instrument. The instrument should not be clenched in the hands or the bow shouldn't be squeezed very tightly between the hands because this will lead to strain. We all have a tendency to over grip, whether it's talking on the telephone, driving a car, writing or playing a musical instrument. In my opinion, this has to do with something called the primitive grasp reflex, which we see in all healthy normal infants up until about the age of nine months, whereby if something is placed into their hands, they reflexively grasp onto it. So this is something that's really built into our nervous systems even though this obligatory response disappears about age nine months. We all have this innate tendency that we have to consciously train ourselves to hold the instrument in a relaxed fashion. One of the ways that we can help have a more relaxed grip on the instrument is by improving the interface between the bow and the hand. The frog of the bow is not optimally designed to fit the hand as we would think of when we're studying ergonomics, for example, which is the science of making the tools fit the worker rather than vice versa. The end of the bow is smooth, it's slippery, it's hard and it doesn't really fit the hand. This can be improved, as you can see here, by slipping some rubber tubing over the end of the bow and that improves the grasp. I like to go one better than this and use something called coban, which stands for cohesive bandage. It's kind of like a stretchy paper ace bandage that's self-adhesive. It will not stick to the bow, but it sticks to itself. And by wrapping this around the end of the bow, when one holds the bow, it will actually mold to the hand and also give improved traction, absorb perspiration, etc. It should be changed fairly frequently because it can get tacky after a while, but it's very inexpensive and available through almost all surgical supply stores or one can contact 3M directly through toll-free information. Here it shows the tail end of the bow being built up to give support for the pinky. This person's pinky kept sliding off the bow and they had problems stabilizing. Notice also that it's wrapped under the index finger and can cushion this area and prevent numbness and nerve entrapment from pressure against the bow. One also has to be careful not to use excessive force with the left hand in pressing down on the strings, but only use as much force as is necessary to get a clear sound. In this regard, it's important to have the proper height bridge because if the bridge is too high, the strings will be higher off the fingerboard and it will require more pressure to press down on them. And one has to be cognizant of using a summer bridge in the summer and a winter bridge in the winter. In terms of muscle strain when one is using excessive tension, it's very common to have strain in the trapezius muscles. This is the muscle seen in the top left corner between the neck and the shoulder. This is a view from the back. The right half is a deeper dissection, the left is the more superficial muscles. And between the point of the shoulder and the base of the neck is the upper part of the trapezius muscle. Regardless of the instrument, this muscle is often tensed and raised and people develop chronic muscle pain in this area. I've often thought why this muscle, why do people tend to hold tension in this muscle and I think that I have some answers. Back in cave person days when beasties used to leap out of the trees onto our necks, it had survival value to hike up your shoulders and tense up your shoulders to protect your neck in the face of danger because your neck is a very vulnerable structure. Well, the thing is that even though these beasts are now extinct, we still have the same tendency to tense up in the face of imagined threats. One of the ways we treat this in the clinic is by the use of biofeedback. One can see in the upper left hand corner on the right trapezius muscle is a surface electrode and this is hooked up to the biofeedback machine and the cellist is watching the level of muscle tension on the screen while she's playing. And this is pretty much what she sees. The two lines, one for each trapezius muscle, are constantly moving and as she tenses up the spikes go up and as she relaxes the line comes down. The goal of this training is to use the least amount of muscle tension compatible with a good musical result and a good musical sound. This strain can also be from a head forward or a forward head posture or position. This sometimes is just simply due to poor posture but it can also be due to the fact that the lighting may be poor or the parts may be poorly copied or the person may need glasses and they're not wearing their glasses and so they're kind of squinting and thrusting their head forward. Thrusting the head in a forward position has the effect of increasing the strain on the muscles in the back of the neck. For example, if the head weighs approximately 10 pounds, thrusting it forward three inches increases the effect of the weight up to 30 pounds so there's three times as much stress on the muscles in the back of the neck and the upper shoulders. So it's no wonder that at the end of the day that these muscles are strained. Another consideration here that we'll get into later when we talk about sitting has to do with the tuning pegs often not permitting the head to be brought back into a neutral position. We'll discuss this in more depth later. We're going to go on and talk now about nerve entrapment at the elbow which while not a common problem is a serious one and one that chelus may be particularly prone to especially in the left arm. The ulnar nerve which is seen here running along the pinky side of the forearm passes in the groove in the funny bone groove behind the elbow on the inner side of the elbow. This nerve runs all the way down into the hand and is extremely critical because it innervates all the small muscles of the hand which are responsible for fine motor coordination. It also gives sensation to the hand as you can see in the top left hand corner in the pinky and half of the ring finger which is indicated. So numbness in the pinky and ring finger often has to do with entrapment of the ulnar nerve at the elbow, the so-called cubital tunnel syndrome. Now this is a cross section of the elbow and in the upper left hand corner you can see the ulnar nerve represented by a black dot within the cubital tunnel which is a fibro-osseous tunnel. In other words it has a fibrous roof and a bony floor. In the top picture the elbow is held out straight what we call an extension and there is ample room for the nerve in the tunnel. In the bottom half in the illustration B the elbow is flexed and there is a passive mechanical narrowing or closing down of the cubital tunnel resulting in compression of the ulnar nerve. This forms the basis for the so-called elbow flexion test that we do in the office. When the elbow is held in a flexed position if the test is positive it provokes pain and numbness and pins and needles radiating into the fifth finger and sometimes part of the fourth finger. This is because the nerve is being stretched and squeezed at the elbow in the funny bone groove also known as the intercondylar groove. In fact pressure measurements that were done within the cubital tunnel in 10 patients with documented cubital tunnel syndrome revealed that the pressure when the elbow was bent or flexed was 63 millimeters of mercury and when the elbow was out straight was only nine millimeters of mercury. This illustrates the dramatic increase in pressure on the ulnar nerve at the elbow when the elbow is flexed. Now this is critical for the cellist because in the left arm when playing in the first, second and third position the elbow is nearly maximally flexed and for much of cello playing these are the commonest positions. Note that even up in thumb position the elbow barely opens up to 90 degrees and this is not to say that all cellists develop cubital tunnel syndrome but certainly if one starts to feel numbness or pins and needles in the pinky or pain at the elbow one should be aware that this may very well represent cubital tunnel syndrome and this is a fairly serious condition again because the ulnar nerve innervates the muscles that coordinate the movement of the fingers. If it's severe enough the way that I treat this is with a hinged splint. The problem is that you just can't remember to not bend your elbow and people bend their elbow hundreds of times a day so repeated elbow flexion or sustained elbow flexion is particularly problematic. This splint has a hinge that's adjustable so that you can allow full extension but it blocks flexion at whatever degree you want to set it at. Usually I'll start off only allowing the person a few degrees of extension and then as the symptoms decrease gradually dial in more and more flexion at the hinge. Once they're up to 90 or 100 degrees of flexion as shown here and they're still asymptomatic then we start to wean them off the brace and hopefully the nerve will quiet down and this won't resume. Notice also the person is leaning on their elbow. This is something that has to be strictly avoided as well because the nerve is very superficial at the elbow and susceptible to compression so one has to be careful not to lean the elbows on hard surfaces. Another nerve entrapment which is not uncommon in cellus is entrapment of the radial nerve at the wrist. This is often confused with tendonitis because there is a common type of tendonitis called de Quervain's tendonitis that occurs in the very same area. In fact in this illustration where you see the arrow labeled radial nerve directly underneath that are two tendons which run through a sheath and the very same thing which aggravates the nerve aggravates those tendons. When those tendons are inflamed it's called de Quervain's tendonitis. When the nerve is irritated it's called sensory radial neuropathy or radial neuropathy. They have similar findings except with the radial nerve problem there is numbness in the distribution of the nerve as indicated in the picture and there may also be a sensation of tingling or pins and needles felt. Now the provocative position for both the tendonitis and the nerve as illustrated here in the top when the hand is supinated in other words when the palm is facing you as you can see in the very top most illustration the nerve is not compressed by the two tendons in the forearm whereas when the palm is face down as in the bottom part of that top illustration the two tendons scissor over the origin of the nerve. In fact at the bottom of that illustration is a circle which represents an enlargement of the area where the nerve emerges from between those two tendons showing how those tendons scissor around the nerve when the hand is palm down. Also on the bottom half of the illustration when the wrist is extended or cocked back the nerve is relaxed when the wrist is flexed the nerve is stretched and bringing the thumb into the palm of the hand which is not shown further stretches it. Now where do we see this okay at the up bow especially as the bow nears the frog the wrist is pronated or even slightly hyper pronated it's flexed and the thumb is adducted into the palm opposite the middle finger and so if one experiences a numbness in the area of the radial nerve or pain at the base of the thumb then what one could simply do at least during practice is to avoid coming too close to the frog say for example avoid the last 25% of the bow to avoid placing the wrist in this position. It's also important not to compress the nerve externally with watches or bracelets etc. Okay nerve entrapment can also occur in the neck or in the cervical spine this is a cross section of the spine at the neck and the nerves are indicated in yellow coming off the spinal cord and emerging through a little canal that's called the foramen which means window in Latin. The nature of these foramen are that when the head is tilted to the side as seen in the leftmost illustration where it says lateral bending the foramen on the concave side become narrowed. When the head is rotated as seen in the far right illustration the foramen on the concave side also become narrowed compared to the neutral position seen in the middle. This shows the nerves this is a side view of the neck and it shows the nerves emerging from the canal there's a little enlargement that circle represents an enlargement so you can see the nerves coming from between each pair of cervical vertebrae. Now if you have arthritic changes there's a narrowing of the openings so the nerves may already be compromised without turning or rotating the neck. This can have an effect in cello playing particularly if as you can see in this illustration from the Kennedy Center this is their principal cellist John Martin if the music stand is to the right so that your head is turned to the right in other words if you're sitting outside stand and you're bowing on your A string towards the frog of the bow so that your arm is way across your body there is a twisting that happens at the neck and this can cause radiating pain down the arm especially if those foramen are already narrowed by arthritic changes. This is a condition that's known as thoracic outlet syndrome and it's a different type of entrapment. As you can see the right arm is extended over the head in the illustration and this causes a stretching of the nerve and blood vessels and potential site of entrapment in three different places. The first one is between the neck muscles which you can see in the illustration. The second one is underneath the collar bone actually between the collar bone and the first rib and the third site is underneath the head of the pectoralis minor which is the muscular insertion where the nerve and blood vessels kind of take a U turn just before they go up the arm and enter the arm. The pectoralis muscles are often tight in cellists because they play with their arms in front of the body and so these muscles can become shortened unless they're specifically stretched. The neck muscles should be stretched as well. I should say that the thoracic outlet syndrome presents with sensations of fatigue or heaviness in the arm. One can get numbness although it's more often the whole hand as opposed to numbness just in the pinkies like the cubital tunnel syndrome or numbness just in the thumb index and middle finger as in carpal tunnel syndrome. Coldness of the hand is another sign of this. This is an illustration that shows what's called an arteriogram, an injection of dye into the blood vessels and then an x-ray taken. This was actually from a cellist that was having severe signs of coldness in the hand and pain and there was strong suspicion that there was significant compression of the blood vessels going down the arm. The top photograph is normal and the bottom one you can see there's a break in the column of dye within the blood vessel where the compression is occurring and this person eventually needed surgery to correct this condition. Again one shouldn't be frightened by this because this is rather rare that one needs surgery. However, the condition itself is fairly common and most often responds to a conservative program of stretching the neck muscles, stretching the pectoral muscles and strengthening the postural muscles. This is a good stretch for the pectoral muscles, sort of the stick them up position bringing the arms back behind the plane of the body and it helps if you take a deep breath when you do this and hold the stretch for about 10 or 15 seconds. One can do this at frequent intervals. I had said we would talk about repertoire as it pertains to injuries. Some composers music tends to be a lot more difficult to play than others. Philip Glass for example, even though I love his music, is reported by many of my patients to be very difficult in terms of its repetitiveness and rapidity and can actually predispose to injury. Some other composers should probably carry a warning from the surgeon general. I'm told by my patients that the Rosenkavalier is particularly a long, difficult opera with lots and lots of playing for the strings and very little place to rest and we've seen a number of Rosenkavalier injuries in our opera patients. Temperature can also play a deleterious effect, especially working in the cold. The polar string quartet seen playing here for a black tie audience may be a sight gag, but playing in cold in general can result in impairment of manual performance. This is due to a loss of cutaneous sensitivity. In other words, you can't feel for example, or you can't feel as well, how hard you're pressing down on the strings or perhaps for intonation. There are changes in the characteristics of the synovial fluid in the joints, which is the fluid that lubricates the joints. Cold causes a thickening of the joint fluid so that it's harder to move the joints. There's a loss of muscle strength and there's also a slowing of nerve conduction in the cold so that the hands don't respond as quickly to the motor impulses from the brain. In terms of technique and posture, one of the things I would like to point out, especially in terms of shoulder problems, has to do with the risks of bowing all the way out to the tip of the bow, particularly on the A string. This puts the shoulder in a position of abduction, which means brought away from the body or held away from the body, and internal rotation, which means somewhat turned in. This can cause a pinching or compression of the rotator cuff in the shoulder. The rotator cuff and the bursa are the two structures that get impinged. On the left-hand side, the long arrow points to the rotator cuff, which is a tendon, and the short arrow points to the bursa, which is like a collapsed sack whose purpose is to help the tendons to glide more smoothly over the bony areas. In illustration B on the right-hand side, you can see when the arm is abducted or brought away from the body, the head of the humerus or arm bone, which is the bottom arrow, pinches the tendon and the bursa up against the acromial arch, which is the upper arrow. That's the bony arch that forms the very top of the shoulder. What can we do to avoid this from happening when bowing out to the tip of the bow on the A string is that one can rotate the cello slightly in towards the bowing arm so that one doesn't have to internally rotate quite as much. In fact, if you watch many cellos, especially people like Yo-Yo Ma as they play, the cello is constantly slightly in motion, being brought in towards the bowing arm when playing on the treble strings and brought back to a more neutral position when bowing on the bass strings. This really helps a lot to decrease the strain on the right shoulder. Notice the smile on the cello's face in this picture because she's rotating the instrument in towards the bowing arm. In terms of the bass, the shape of the instrument is important as well, particularly if the player is of short stature. Here this student is playing up in thumb position, but she's having to lift her elbow way up in the air in order to avoid impinging the underside of the wrist against the front edge of the bass. If she didn't do this, if she didn't lift her elbow and arm up, then she would impinge as seen here. Now, partly this could be avoided by having a more sloped shape to the upper part of the bass as opposed to somewhat more squared off configuration as seen here. And this fellow is taller and so he doesn't have the same kind of problems. Also, the bass has much more sloping shoulders providing easier access to thumb position. Let's talk a little bit about the angled end pin and what it does and sort of the physics behind it. This of course was popularized by Rostropovich, although I don't believe he was the inventor of it. In any event, what it does is it allows the cello to be held at a much more steeply inclined angle without having the end pin have to be excessively long or stick out excessively far in the front. A lot of people like to have the cello at more of an angle because then gravity assists the arms and one doesn't have to use as much muscular force in either bowing or pressing down with the left hand. The drawback however is that the bowing arm is brought up higher and so there's more risk of shoulder impingement as we saw in the earlier slides. Another thing that it does by the way is it brings the end pin more directly underneath the instrument so there's not as much weight thrown back against the shoulder and so it makes it easier to sit up straight when one plays. And of course in terms of strain it's not just playing the instrument but getting it home after the concert and if one is a small player as seen here then one has to be strong first of all and second of all maybe be clever in getting the instrument around. It always seems to be unfair, you can see on the left the big guys play the little instruments and the little guys play the big instruments. So carrying the cello for example hanging it from the end of the arm and we've weighed the cello in the case can weigh up to about 35 pounds. This can actually be a source of shoulder strain as well. You see one of the things that happens in the bottom illustration which represents the rotator cuff, the sort of darkened area is the muscle and then there's the rotator cuff tendon and then showing it inserting into the bone and what this illustration is showing is the blood supply to the rotator cuff. Part of it comes from the muscle and part of it comes from the bone but there's an area where they meet that has a relatively poor blood supply which is called the critical zone. Now on the right hand side of the lower illustration the downward arrow which says traction under is what happens when you hold a weight in your arm. There's traction that happens on the rotator cuff and the two large white arrows at the critical zone show the cuff becoming relatively avascular, in other words the blood flow being shut off to this area of the tendon when you hang a weight in your arm. So it's not quite like the impingement that we saw before but you can get rotator cuff problems from carrying your cello in your hand especially for long periods of time. Okay, regarding back disorders we already mentioned carrying the instrument. There are a number of instrumentalists that have a relatively high incidence of back disorder. The first one or the highest is cello, then harp, piano and double bass. Cellists have a particular problem in that the instrument is more or less constraining. If you sit and watch a violinist during a string quartet they're often moving around quite a bit in their seat whereas the cellist is more or less kind of stuck there by the instrument. Also as we mentioned sometimes the tuning peg makes it difficult to sit up straight and then there are the back problems from carrying the instrument around. For example here with the bass it's an awkward instrument to get around and so the back is often not in an ideal posture here leaning to the right in order to accommodate the instrument. Wheels can be very helpful in this regard. Some cello cases have built in wheels as seen here. Wheels can be added onto the case or onto the instrument. Cellists are also carrying the stool around many times as well. This patient of mine actually had a backpack arrangement affixed right to her case. She went to a mountaineering store and had waist straps and shoulder straps put right on her cello case. Now she's able to carry it around like this which is putting most of the weight on the hips not even on the shoulders and this was very satisfactory. There are lightweight practice instruments that are available. This one is called the Traveiello and for people that do a lot of traveling and want to take their instrument along to practice this may be a good alternative. This is Ernest Nussbaum from Bethesda Maryland. You can't quite make out his address in the lower left hand corner but he is in the phone book and if anyone is interested in a Traveiello give him a call. This is a sculpture I came across of a lightweight Traveielist playing his Traveiello. I thought that was pretty funny. Let's talk a little bit about chairs and how it relates to back pain in playing the cello. The chair was really devised as a device for ruling not really for working. The King Tut's head is cut off here in this slide but it's an ancient Egyptian sculpture showing the chair as a throne not really designed for working. The mechanics of sitting are such that the spine on the left hand side is in the ideal or neutral position with the normal lumbar, lumbar meaning the low back, normal lumbar curvature or lordosis. In the middle picture when one is sitting on a flat chair there is a backwards tilting of the pelvis, notice the white arrow within the black of the pelvis or hip bones that causes a flattening of the lumbar spine and a loss of the lordosis. This isn't so bad if you're leaning back against the back rest of the chair but as most of you know most cellists do not use the back rest of the chair they sit forward in the chair so they can get the cello between their legs and so there's a slumping of the low back or a flattening out of the low back that causes strain of the back and causes the head to be relatively thrust forward. In the rightmost illustration we see the effects of using a forward sloping seat once again placing the pelvis in the upright or neutral position and restoring the lumbar lordosis in an effortless manner, in other words you don't have to use a lot of back muscles to sit up straight when the seat slopes forward, you do have to use a lot of back muscles to sit up straight on a flat seat and this causes fatigue and strain. This shows the effect on the pelvis and low back of various seat angles. On the left side if the seat slopes backwards there is even more of a reversal of the lumbar lordosis and backwards tilting of the pelvis, this really causes a lot of back strain. Now what seats slope backwards? Very common for folding chairs to slope backwards, the idea I suppose being to encourage you to sit back into the back rest but if you're trying to play a cello in a backward sloping chair this can cause an enormous amount of back strain. In the middle and rightmost illustrations we see the effects of a very slightly forward sloped seat or a more radically sloped seat, on the right hand side it nearly completely straightens out the spine using the forward wedge. This is just an illustration of the slumping of the low back that occurs with sitting on a flat chair with the hips and knees at 90 degrees, total reversal of the lumbar lordosis and a curvature of the spine. Here is a cellist sitting on a chair that slopes backwards causing a lot of back strain. If you tip the seat forward, kids know this instinctively and they'll tip the chairs onto the front legs, makes it much easier to sit up straight. Now the idea of a wedge cushion to alleviate back pain has been around for a long time. This is an illustration of a horse cab from the turn of the century and the drivers since there was no back rest found very quickly that if they sat on a flat cushion they would get back pain but if they used a forward slope then they would have no back pain. In fact if you think about riding a horse the reason you don't need a back rest when you ride horseback is that your thighs slope downwards which in effect brings the weight of your torso directly over your sit bones so you're balanced and there's no force acting on you to kind of force your back backwards. So here is the foam wedge cushion. This is called the Ergo Kush and it's available from Alimed, A-L-I-M-E-D which again you can find through toll free information, 800 information. They're up in Dedham, D-E-D-H-A-M, Dedham, Massachusetts and the cushion is dual layer. The top one inch is a soft open cell foam and the bottom two inches is firm closed cell foam. The soft foam gives comfort, the closed cell foam gives firmness and support so the whole cushion doesn't squash down and flatten down. And basically I'll back up here, you can see that it converts a backward sloping seat into a forward sloping seat. It's very lightweight and easy to carry around and many professional cellists around the country use them including Jules Eskin at the Boston Symphony and many members of the National Symphony. And here are cellists. It doesn't quite make it into a forward sloping seat here because the seat is so radically sloped backwards but at least it turns it into a more or less level seat. Here's another example of just a plain foam wedge being used to create a forward sloping position and again making it very easy to sit up with a nice straight back with very little muscular effort. Regarding posture and sitting in back pain, one of the common mistakes particularly that beginners at the cello make are having the instrument be straight up and down as you can see here and the torso leaned to the, in this case to the viewer's left, to the player's right so the spine is crooked, the instrument's straight but the spine is crooked. So one needs to make sure by checking in the mirror that you first set yourself straight and then place the instrument and the instrument will by necessity be sloping slightly to your left. Now one of the new inventions that I think is really interesting and maybe very helpful in terms of posture is called the posture peg but this is a removable tuning peg so that after you finish tuning the instrument you just simply pull the peg out. It's got kind of a square rod that fits into a square hole and this has the effect of leaving a flat profile on the side of the instrument that faces the left side of the head and neck. This would allow in effect the person to sit with the head in a much more upright position as you can see in the bottom compared to the top illustration with the tuning peg in and the head forward. Again, the forward head posture causes a lot more neck and upper back strain. Now we all talk about playing a musical instrument but we should be aware that it really is work to play an instrument. The sign says in Finnish musicians working is taken at the Kumo Chamber Music Festival in Finland where I was a number of years ago. It's a gorgeous place if anybody has the interest to go there, it's sort of like the Tanglewood of Finland where players from all over Europe come for the summer. In any event, therapeutic exercises are very, very important for musicians and since cellists are particularly prone to back pain I'm going to quickly go through a series of back exercises that one can do. First of all, abdominal strengthening by doing sit ups and remember these are just crunches in other words you're not coming all the way up which can strain the back but you're just coming part way up. This is really adequate to strengthen the abdominal muscles. Stretching the low back in this position, this could be held for about 30 seconds. This is called the cat of the camel position, the next one will be the cat and they're done in sequence so you go from this one to the next one which is called the cat, in other words arching your back. This gives flexibility to the spine and strengthens the spine. The cobra pose from yoga which also is for flexibility of the low back. The so called boat pose where one is just kind of resting on the hips with the upper torso and both legs lifted off the floor of the table. This is an excellent exercise for strengthening everything from the back of the neck muscles all the way down to the buttocks and the hamstring muscles. Again you would hold this posture for about five seconds then let it down. If hyperextending the back is uncomfortable then you can roll up a pillow and put it under the hips so that you start off in a flexed position and then when you arch up you'll only come to a neutral position of the spine and it won't cause hyperextension of the low back. Of course prevention is the best treatment of all and prevention really has to do with general physical conditioning for strength and flexibility and a good general physical conditioning program should contain elements of cardiovascular conditioning such as aerobics, jogging, biking, nordic track, what have you. Something for strength such as light weight training and flexibility such as yoga or stretching. Then specific exercises for strength and flexibility because each instrument has their own specific demands. So as we mentioned cellists need to focus in on a back program and also make sure they stretch the pectoral muscles which tend to get tight from the typical posture of playing the cello. Then body awareness regarding posture and tension, in other words proper posture can only be brought about through awareness of the body. Things like Alexander technique and Feldenkrais technique are excellent in this regard as is yoga and meditation. And then smart practice habits and by this we mean taking frequent breaks perhaps a five minute break every half hour or every hour. Not practicing very difficult or awkward passages over and over and over again but limiting the practice time of a difficult passage to two or three minutes perhaps and then going to something easier and then coming back. And just generally being aware of one's health and having good healthy habits. I'd like to leave you with a paraphrase and a thought from St. Francis who said life or in this case a musical career is a long hard road. Be kind to your ass for it bears you. Thank you. Thank you for your presentation.