[Music] hello and welcome to another complete cambridge igcsepe lesson this is the fourth lesson in the chapter on the musculoskeletal system muscles as always we'll be focusing only on the learning objectives found in the official cambridge textbook and will cover absolutely everything you need to know for your final exam our three learning objectives today are to know the location and role of the major muscles to understand the importance and role of tendons and to provide sporting examples for the movements each muscle creates so let's begin with the first muscle is simply a band of fibrous tissue that has the ability to contract or produce force creating movement in the body there are 13 muscles that you need to be able to locate and the first is the trapezius it can be found at the upper portion of the back and the neck and don't worry we'll cover the role of each muscle and the movements they create later on in the video the deltoids of the shoulder muscles which cover the front top and back side of the ball and socket joint the pectorals your chest muscles while the biceps and triceps are located on the front and back of your upper arm respectively like the trapezius the latissimus dorsi is also a back muscle it spans the middle and lower sections of the back and the whole width of the body the abdominals or abs cover the abdomen or core they're comprised of the central rectus abdominus muscles and the obliques just outside them the hip flexors as the name suggests found the hip joint at the front from the spine and pelvis to the femur below your gluteals or back side muscles sit directly behind the quadriceps and hamstrings are your thigh muscles they are some of the longest muscles in the body spanning the whole length of the femur the quadriceps sit at the front with the hamstrings at the back the gastrocnemius is the largest of the cast muscles it works alongside the tibialis anterior which is located at the front of the leg beside the tibia or shimbo our second learning objective is to understand the importance and role of tendons in relation to the muscles as you'll know if you've watched my first lesson on the skeleton and its functions tendons connect muscle to bone when a muscle contracts it therefore pulls on the tendon which pulls on the bone and creates movement at the joint in this example a tendon connects the bicep muscle to the radius in the forearm as the muscle shortens the forearm is pulled upwards and flexion occurs at the elbow now let's wrap up the lesson and move on to our final learning objective make sure that for each muscle you're able to describe a movement that it creates and provide an example from sport to demonstrate your understanding if you need to recap the movements of joints take a look at my last video by clicking on the banner now we'll begin again with the trapezius this muscle holds and rotates the shoulders and attaches to the base of the skull enabling us to move the head backwards and sideways contracting the trapezius enables the swimmer to rotate their neck while breathing the deltoids pull on the humerus as they contract moving the arm forwards sideways and backwards at the shoulder joint all these movements combine when performing skills such as an overhead clear in badminton next to the pectorals which also attach to the humerus and abduct or pull the arm in at the shoulder we use the pectorals to pull the arm towards the center line of the body when throwing a discus or hitting a forehand drive in tennis the biceps bend the arm by creating flexion at the elbow and are used to draw back the bow in archery the triceps have the opposite effect they straighten the arm at the elbow when they contract and therefore play a key role when throwing a shot put or javelin and jabbing in boxing the latissimus dorsi pulls the arm downwards and backwards of the shoulder joint so we're mostly looking at examples that involve pulling movement such as rowing the latissimus dorsi creates extension at the shoulder of the swimmer as they pull their arm and propel themselves through the water the abdominals create a pull in the spine enabling us to bend forwards a nice example of this is when the abs contract allowing divers and gymnasts to flex at the spine and adopt a pike position in flight the hip flexors allow flexion at the hip joint by pulling on the femur and drawing the leg forwards and upwards we use our hip flexors every time we raise our knee while running and when kicking a football the gluteals or glutes work in opposition to the hip flexors by pulling the legs downwards and backwards at the hip the muscle is important for long and triple jumpers when taking off but also enables some sideways movement or abduction which is essential for hurdlers when raising their trail leg the quadriceps straighten or extend the leg at the knee and therefore have a major role to play in jumping running and kicking the quads assist in propelling the high jumper into the air and allow the rugby player to generate distance when kicking at goal while the quads extend the leg the hamstrings produce flexion pulling the lower leg backwards at the knee this occurs during the running stride when transitioning from the push off to the heel strike phase and when drawing the leg backwards in preparation to strike a football our final pair of muscles are the gastrocnemius and tibialis anterior gastroenemia pulls on the achilles tendon which is attached to the base of the foot and enables plantar flexion or the straightening of the ankle joint pointing the toes in gymnastics or taking off for a layup in basketball are great examples of this in contrast the tibialis anterior pulls the foot upwards or creates dorsiflexion at the ankle joint the muscle contracts from toe kicking in football and also helps to raise the toes during the running stride now we have just covered everything you need to know on topic 1.4 the muscles i know there's a lot of information squeezed in here which is why i recommend you go back and watch this video again take some notes if you like and practice applying what you've learned to some past exam questions as always i hope you found this video useful and i will see you in the next [Music] one