2.17. The Role of the muscles when playing percussion

2.1. Bones


   The bones of our body make up the skeletal system which can be divided into three categories. The axial skeleton includes the bones of our head, neck trunk and spine, the lower appendicular skeleton involves our hips and feet and the upper appendicular skeleton which we are most interested in, covers our shoulders, arms and hands.

   The bones of our bodies are made from highly specialized hard form of connective tissue which enables the to provide protection to the vital organs and withstand extensive load. The time it takes for the bones in our bodies to develop varies greatly but for example, the humerus (bone of the upper arm) starts forming when we are an eight-week-old embryo and will not be fully developed until we have reached the age of 20 (Moore and Dalley, 2006, p. 18-19).

2.6. Upper appendicular skeleton

   

   Let's examine the upper appendicular skeleton starting with the shoulder. The shoulder is made up of the shoulder blade, the clavicle and the humerus of the arm resting in the glenoid socket of the shoulder blade. The shoulder is the most mobile joint in the body and is able to move 360°. 

   The range of the movement of the arm is dependent on the position of the shoulder, so a mobile shoulder frees up the arm. There are four muscle groups which are attached to the shoulder blade or the humerus and affect the shoulder: the anterior (chest) muscles, the posterior (back) muscles, the rotator cuff and the deltoid.(Moore and Dalley, 2006, p. 848).

2.3. Muscle types

 

   The bones would not move without muscles pulling on tendons that are attach to the bones. The muscular system can be separated into three categories: smooth muscle, cardiac muscle and skeletal muscle.  Smooth and cardiac muscles are involuntary muscles which are controlled by our autonomic nervous system. They regulate body functions such as breathing, heartbeat and blood flow. The skeletal muscles are muscles we can control with our own decisions through the somatic nervous system.

   Muscles are constructed from microscopic muscle cells commonly named muscle fibers. When we make a movement, we order the muscle fibers to contract which makes the muscle shorten. A muscle can only be contracted, when a muscle lengthens it is because another muscle contracts or gravity pulls a limb back to neutral (Moore and Dalley, 2006, p. 30-39).

2.4. Tendons


   Movement would not be possible without the presence of tendons but as they connect the muscles to bones, they are often considered as a part of the muscle they serve. Tendons are strong, not very rigid connective tissue made up of collagen fibers like the bones. Tendons and ligaments are very similar in compositions but the difference is that tendons connect muscle to bone and ligaments connect bone to bone. Tendons are formed at the end of muscles and become smaller and smaller until they connect to a specific spot on the bone (Moore and Dalley, 2006, p 30-39).

2.5. The Anatomical body

 

   When getting to know the human body biology, it is important to know the anatomical body. This can come in handy trying to describe your pain’s source and for medical professionals to properly locate things on your body. The anatomical body is a position where you are standing straight up with feet forward, head high, arms down to the side with a flat palm and thumbs facing out (Moore and Dalley, 2006, p. 5).

2.7. Chest

 

   The anterior chest muscles are pectoralis major, pectoralis minor, subclavicus and serratus anterior. This group of muscles is mostly responsible for forward and upward motion of the shoulder blade as well as moving the humerus of the arm towards the body.  The pectoralis muscles are the prime movers of the arm in front of the body and can generate the most force of the four. Subclavicus is a stabiliser for the clavicle and the serratus anterior is a stabiliser for the shoulder blade. The serratus anterior is quite important because it holds the shoulder blade against the ribcage which is very important for overall shoulder stability (Moore and Dalley, 2006, p. 752).

2.10. The Rotator Cuff


   The rotator cuff is often mistaken for only one muscle but it is actually a group of four muscles: supraspinatus, infraspinatus, teres minor and subscapularis. This is a small but important group of muscles that are not visible, so they are often neglected. The main function of these muscles is to hold the humerus in the shoulder joint since they all originate at the shoulder blade and attach at the humerus. All of them, with the exception of the supraspinatus, rotate the humerus externally while the supraspinatus helps the deltoid to raise the arm out to the side (Moore and Dalley, 2006, p. 761-722).

2.13.1 Forearm flexors

 

   There are eight forearm flexors which have three layers. The superficial (first) layer has four muscles: pronator teres, flexor carpi radialis, palmaris longus and flexor carpi ulnaris. The intermediate (second) layer has one muscle called the flexor digitorum superficialis. The deep (third layer) has three muscles: flexor digitorum profundum, flexor pollicis longus and pronator quadratus.

   The forearm flexors are responsible for for flexion of the forearm either of the wrist or the fingers at the first metacarpal as well as moving the wrist from side to side. As their name suggests, the pronator teres and pronator quadratus pronate the hand or rotating it placing the thumb towards the body if looking at the anatomical body (Moore and Dalley, 2006, p. 803-809).

2.15. The Hand

 

   Moving down the hand the five metacarpals make-up the palm and the phalanges make-up the fingers. Each digit has three phalanges except the first one (the thumb) which has two. Anatomically the fingers are numbered from 1-5 from thumb to pinky.

   Where the fingers attach to the palm we get a hinge joint called the Metacarpophalangeal joint and the joints between the fingers are called the proximal and distas interphalangeal joints (Moore and Dalley, 2006, p. 869-873).

2. RELEVANT ANATOMICAL INFORMATION



   To understand injuries and how we can prevent them, some basic biological knowledge is essential. We will now look at the skeletal and the muscle skeletal systems of the arms.

2.8. Back

 

   The posterior back muscles are latissimus dorsi, trapezius, levator scapulae and rhomboids. The trapezius, rhomboid and levator scapulae originate at the spine and attach at the shoulder blade to the spine. These muscles work to stabilize the shoulder blade as well as pulling it back (towards the spine) and moving it up and down (retracting the scapula). The latissimus dorsi originates back at the hip and is attached to the humerus so it stabilises the shoulder by countering the pectoralis muscles in the front as well as moving the humerus towards the body when it is in front (Moore and Dalley, 2006, p. 753-755).

2.9. The Deltoid

 

   The deltoid is a single muscle on top of the shoulder joint with three heads. It primarily moves the humerus since it originates above the she shoulder joint, crossing it and attaching to the humerus. The three heads of the deltoid are often referred to as the anterior, lateral and posterior deltoid and help to move the arm to in front of the body, to the side of the body and behind the body (Moore and Dalley, 2006, p. 755).

   These four muscle groups play the role of stabilizing the arm in and around the shoulder joint. The balance between them also influences the posture of our shoulders which is very important for mobility and strength of the arm muscles. If the chest muscles are tight  and the back muscles are weak, it will lead to rounded shoulders (Moore and Dalley, 2006, p. 755).

2.12. Muscles of the upper arm

 

   The upper arm has five muscles: two primary movers, biceps brachii and triceps brachii, their function is to flex and extend the elbow. The bicep and tricep have attachments above the shoulder joint so they also affect the humerus when lifting the arm and pulling the arm down. The other three muscles: brachialis, coracobrachialis and anconeus are more supportive and stabilizing muscles with the exception of the brachialis which is a forearm flexor at the elbow joint (Moore and Dalley, 2006, p. 788-789).

2.18. Common forearm injuries

2.18.3. Muscle tension

   

   Muscle tension is very well-known problem among the general population. However, modern medicine does not have a very clear explanation why our muscles tense on a biological level but, we know what the causes might be.

   Some of the factors of muscle tension can be related to muscle soreness when the body’s muscle repair mechanism is working. When we eccentrically contract muscles like lowering a dumbbell in a bicep curl, the muscles stretch, lengthen which creates tiny tears. This causes inflammation in the muscle, creating pain and stiffness while the muscle recovers. After recovery, new muscle fibers have been formed and the muscle is stronger (Moore and Dalley, 2006).

   Muscle fatigue and overuse can also cause tightness or muscle rigidity. It might happen if the muscles are tensed for too long and do not get a chance to relax and lengthen. When we want it to relax, the muscle will stay partly contracted, leaving us with muscle tension or muscle pain. It can lead to build up of lactic acid in the muscles which causes them to harden and restrict mobility (Healthline, 2020).

   Muscle tension has also been linked to stress and anxiety as shown/viewed in a literary review by Pluess et al. in 2009. When anxiety levels rise, the brain triggers a fight-or-flight response which has been “designed” to prepare the body to fight or flee when danger sets in. That causes muscles to tighten and can lead to chronic pain (Pluess et al, 2009).

2.2. Joints

 

   The joints of the upper appendicular skeleton are the shoulder joint, the elbow joint, the wrist joint and the phalangeal and interphalangeal joints in the palm and fingers. A joint is where bone meets another bone. There are three types of joints: synovial joints, fibrous joints and cartilaginous joints. Fibrous joints and cartilaginous joints are less mobile or not mobile at all, like the joints between the bones of the skull and our vertebrae. Synovial joints are the more mobile joints in our body make up most of the joints that we control with our muscles.

   Synovial joints can be divided into groups based on their movement patterns such as hinge joints or ball and socket joints. The joint is surrounded by the joint capsule which is made up of the ligament that attaches bone to bone and the synovial membrane which creates a space inside the joint. That space is filled up with synovial fluid which acts as a lubricant for the heads of the bones, so they slide smoothly inside the joint. The heads of the bones where bone meets bone, we find articular cartilage. Cartilage absorbs shock and protects the head of the bones from damage (Moore and Dalley, 2006, p. 19-20 and 26-29).

2.13. The Forearm

   The forearm muscles are divided in between what functions they have in the forearm. If we refer to the anatomical body, we find the flexors on the anterior (front) side which flex the wrist, and the extensors on the posterior (back) side which extends the wrist (Moore and Dalley, 2006, p. 803-809).

2.14. Wrist

   The wrist is a very complicated joint. It originates at the end of the radius and ulna where the eight carpal bones meet. These eight bones make the wrist very mobile but also unstable. The carpal bones are the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and the hamate. (Moore and Dalley, 2006, page 869-873)

2.16. Intrinsic hand muscles

 

   The hand has many small muscles called the intrinsic hand muscles because they originate and insert in the hand. There are four thenar muscles: adductor pollicis, abductor pollicis brevis, opponens pollicis and flexor pollicis brevis which together flex and bend the thumb. We have three hypothenar muscles: abductor digiti minimi, flexor digiti minimi and opponens digiti minimi which all flex and bend the pinky.           These first two muscle groups are responsible for the individual motions of the thumb and pinky. Next are the four lumbrical muscles which are named the 1st, 2nd, 3rd, 4th lumbrical muscle. These muscles flex fingers 2 - 5 (index  to pinky) or move them towards the palm and extend the first fingers joint (interphalangeal joint). Rounding out the hand we have the dorsal interossei muscles 1 - 4  in the palm abduct or spread fingers 2 through 5 and the palmar interossei muscles 1 - 3 also in the palm pull the fingers together (Moore and Dalley, 2006, p. 808-814).

   The snare drum roll utilises internal and external rotation of the forearm. The muscles responsible for this motion are the rotator cuff and the deltoid. However, the flexors and the extensors of the forearm are also working to hold the wrist stable. Here the back muscles also plays an important role in keeping the shoulder blade stable.

2.11. The Elbow

   

   At the end of the humerus, the radius and ulna - the two bones of the forearm meet to form the elbow. This is a hinge joint with the main carrying load on the ulna. The radius and ulna have two joints between them called the proximal radioulnar joint and the distal radioulnar joint which allow the radius to travel over the ulna allowing us to supinate and pronate the arm (Moore and Dalley, 2006, p. 860).

2.13.2. Forearm extensors


   Our body has twelve forearm extensors which have also three layers. The superficial layer (first layer) includes extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi and extensor carpi ulnaris. This layer has the strong extensors of the wrist and the extensors of the fingers. The deep layer (second layer) includes the supinator and the extensor indicis. The supinator supinates the forearm and rotates the thumb from inside to out.The extensor indicis extends the index finger. The third layer of flexors is called the outcropping deep layer. Abductor pollicis longu, extonsor pollicis longus and extensor pollicis brevis. Pollicis is the latin word for thumb, therefore these muscles are responsible for movements of the thumb in different directions (Moore and Dalley, 2006, p. 803-809).

2.18.1.Tendonitis

 

   The word tendonitis refers to a swelling in a tendon which leads to discomfort and/or pain. Tendons are the connection between the bones and the muscles so when a muscle contracts, it pulls on the tendon which moves the bone. Tendons originate in muscles and are made of fibrous connective tissue. Tendonitis can be developed in various ways but most commonly due to overuse. The muscle pulls on the tendon which moves the bone and that creates the movement. When that happens, a little bit of stress is applied to the tendon which, if done repeatedly without proper rest, leads to small damage or tears in the tendon. Most of the time these damages heal in a short time or are so small that they are not really felt. When it does not manage to recover before we start doing our repeated movement again, we further damage the tendon which causes inflammation leading to pain and lack of mobility. 

   When we get tendonitis in a certain place on the body, it has been given a name related to the motion it controls. For example the tennis elbow (lateral epicondylitis) which is caused by the inflammation of the tendon that is connected to the lateral epicondyle of the forearm (Agabebi, 2005).

   According to doctor Ingólfsson, tennis elbow is the most common form of tendonitis he sees in the population. Some other tendonitis conditions come with names such as the golfer’s elbow, jumper’s knee, De Quervain’s and few others. But in fact, every tendon in the body will get damaged if it is overused. However, the good news is that tendons can be strengthened which is very important to do during recovery from tendonitis (Moore and Dalley, 2006, p. 813 and Agabegi and Agabegi, 2005, p. 436-437).

Figure 21: Timpani single strokes (Þorleiksson, 2020). 

   The Timpani single stroke is a very physicial technique. When moving the stick away from the drum we use the back muscles to retract the scapula and the deltoid helps the latissimus dorsi to pull the arm back. Notice also the bicep and the brachioradialis flexing the elbow while the forearm extonsors bend the stick back.

   The down stroke is performed by pushing the humerus forward with the chest and the deltoid, extending the elbow with the tricep and flexing the wrist with the wrist flexors.

   All this happens while the intrinsic hand muscles and muscles of the forarm flexing the fingers hold the stick in the hand.

Figure 23: A snare drum roll (Þorleiksson, 2020).

Figure 13: Deep forearm flexors (Teach Me Anatomy, 2018c) .

Figure 3: Smooth, skeletal and cardiac muscle (Wikipedia, 2020c) .

Figure 19: Muscles of the hand (Teach Me Anatomy, 2018e).

Figure 6: Pectoralis major (Teach Me Anatomy, 2017a).

Figure 10: The Rotator Cuff (Teach Me Anatomy, 2020b).

Figure 15: Forearm extensors (Teach Me Anatomy, 2020c) .

Figure 24: (Þorleiksson, 2020) Snare drum single strokes

   A typical motion when playing with two mallets in one hand is the supination and pronation of the wrist. The difficulty of this movement increases when the arm needs to reach down the instrument. There can also be differences in how much the supination and pronation muscles have to work based on the girp used to hold the mallets.

Figure 22: Pronation and supination during four mallet playing (Þorleiksson, 2020). 

2.18.2 Ganglion cyst


   A ganglion cyst or a synovial cyst is a cyst that usually forms inside a ligament filled with synovial fluid. The cause of a ganglion is not clear but it is often associated with the areas of the body that have had some sort of trauma, injuries or overuse. The most common symptom for a ganglion cyst is a visible bump under your skin, most commonly around the more mobile joints such as elbows, knees or wrists. This condition has sometimes between called a bible cyst because people used to hit the cyst with a bible to pop it, allowing the synovial fluid to be removed from the cyst.

   There are usually three treatments for it in the modern medicine (Ingólfsson, 2020). The first one is rest (for the joint) so the cyst could empty on its own and disappear/go away. The second option which is often performed by a general physician, is draining of the cyst with a needle which is poked inside the cyst and the fluid is drained out. It has been proven to be very unreliable method because the cysts return in about half of the cases where that particular treatment has been performed (Head et al, 2015). The most permanent but also the most painful treatment is surgery where the cyst is surgically removed. The origin of the cyst can be deep in the joint and when there is a need to surgically remove the cyst, it usually means that it is pressing against a lot of sensitive nerves. Even though this surgery has a very high success rate, it means that the recovery process can be very painful and very varying between 3-6 months (Moore and Dalley, 2006, p. 813-814).

2.18.4. Carpal and cubital tunnel syndrome


   Carpal and cubital tunnel syndromes are nerve compression syndromes. The median nerve and the ulnar nerve travel through special tunnels so the sensory signals can travel when the joints are under flexion or extension. These tunnels can become inflamed through the repetitive motion or an injury therefore restricting the space for the nerve inside these tunnels. When inflammation starts to press on the nerve, it can produce pain, muscle weakness and loss of sensation or tingling in the hand.

   Whether a patient has carpal tunnel or cubital tunnel can easily be diagnosed by where the numbness if felt. The median nerve which gets entrapped in the carpal tunnel leads to the numbness in fingers 1,2,3 and outer half of finger four(thumb to ringfinger). The ulnar nerve which gets trapped in the cubital tunnel leads to numbness in inner half of 4th finger and 5th finger.

   Carpal tunnel syndrome is much more common than cubital tunnel in the general population according to Doctor Ingólfsson. Treatment to this disease is rest since it is an inflammatory disease. When that doesn’t work, surgery is an option and is performed a lot with a very good success rate(Ingólfsson 2020).(Moore and Dalley, 2006, page 840 and 843)

   The snare drum single stroke mostly ultilizes the forearms when moving the stick. However, the bicep, brachioradialis and the deltoid are working to hold the elbow and the shoulder stable.

Figure 12: Muscles of the upper arm (Teach Me Anatomy, 2018b).

Figure 18: The Hand and fingers (Sendi et al, 2019) .

Figure 7: Pectoralis minor and serratus anterior (Teach Me Anatomy, 2017b).

Figure 20: The interossei muscles of the hand (Teach Me Anatomy, 2018f).

Figure 16: Deep forearm extensors (Teach Me Anatomy, 2020d).

Figure 17: The Wrist joint (Teach Me Anatomy, 2019b).

Figure 2: A synovial joint (Wikipedia, 2020b). 

Figure 14: Superficial forearm flexors (Teach Me Anatomy, 2018d).

Figure 1: The Upper appendicular skeleton and the lower appendicular skeleton (Wikipedia, 2020a).

Figure 5: The Shoulder joint (Teach Me Anatomy 2018a) .

Figure 8: The Back muscles (Teach Me Anatomy, 2020a) .

Figure 11: The Elbow joint (Teach Me Anatomy. 2019a) 

Figure 4: The Anatomical body (Pngwave, 2020).

Figure 9: The Deltoid (Wikipedia, 2020d).