okay class here's the third lecture of the course we're going to be talking about the biomechanics of resistance exercise so what is biomechanics basically the mechanisms through which the body moves is what we're looking at with biomechanics so this is looking at bones tendons ligaments everything working together to help put the body in motion so looking at the skeletal system the skeletons basically broken down into two components we have the axial skeleton and the appendicular skeleton the axial skeleton is basically the trunk component where everything is here in purple so we got the skull the ribs the spinal cord a spinal column and the sternum the appendicular skeleton or the think of appendages everything extending off the body from the trunk everything here in pink so the legs the hip and shoulder girle everything right here so basically components of the body that are moving is the appendicular skeleton so two sections of the skeleton axial and appendicular now in the skeleton as we know we're movement occurs at the joints but this isn't always the case if we look at the fibrous joints these are the sutures in the skull for instance there is no movement that occurs here it's just fused together these are the components of the skull that is formed from the development from infancy to adulthood as our brains grow the you know skull had to envelop and adjust accordingly so fibbr fibus uh joints no movement occurs these are these little cracks mainly only found in the skull next we have the car agous joints there's limited movement in in these joints and these are more the vertebral discs located in the spinal spinal column so I know you probably look at some people like the contortionists say wow they're really flexible they can bend their head all the way back to their back side but it's not because each one of these can stretch so far or bend so much it's just the all of them moving working as a team which gives you that full range of motion so each one of these individual discs there isn't that much movement allowed like side to side lateral movement or bending and stretching here so these supposed to keep the spine somewhat intact in alignment so it's not to damage the spinal cord that runs up and down uh the the spinal column itself next The sovial Joint these are in the nip uh the the knees the hips the shoulders this is where most of the movement occurs and where there's more the more mobile a joint is the more prone to injury it is so this you know this is where we have more of the ACL tears and hip dislocations because it's most in the joints that have allow the most Mobility so with the sovial joints there's three types um you got the unial bi axial and the multiaxial so the uni axial joint is our hinge joints our elbow knees basically just moving in one plane of motion flexing and extension all right then we have our bi axial joints they only move in two axes perpendicular you know up and down left to right so I know you know you think the risk oh that can move move 360° but if you were to grab your actual forearm locking in the old on radius you wouldn't be able to actually rotate the hand so it's the form that allows the rotation of the hand not the wrist itself so it's really just flexion extension up and down motion with the hand side to side moving from towards the thumb and the pinky in the wrist so the uni axial one one axis bi axial two two axis then we have the multiaxial uh joints this is the ball and socket joint your shoulder your hip that allows the full range of motion through throughout the uh movement but now if you look at the bone itself so we have two articulating ends there's cartilage on each surface this keeps it smooth and allows there to be no catching and a little bit more of a gliding motion when the bones move and then we have the uh synovial fluid in between this cushion-like gel-like um substance in between the bones now this provides extra cushioning and lubrication to allow there to be smooth movement of the two bones so um yeah so moving on to cartilaginous joints again we talk about the spinal column so as you can see all the little all the cartilage between each and one of these little things so big thing to know about the vertebral column is it's broken down in sections we have the cervical which is more around the neck there's seven components there then we have the thoracic now and then the the lumbar now the biggest thing that most people get confused here is that the thoracic spine is where we want to have more Mobility ility and flexibility not so much the lumbar the lumbar is the base the trunk the lower body so when you're you know squatting deadlifting running jumping this is like kind of the foundation that everything's resting upon the more mobility and flexibility you have in thoracic spine the better shoulder mobility and range of motion you have so this is when you see the people doing back stretches this is what you more want to try to stretch out not so much the lower back okay then after the Lum lumbar we have the the sa sacral component all right so this is about five little components of bone here and then at the end we have the Coxx or the coxal bone this is where you have three to five and they're usually fused together okay so now five sections cervical thoracic lumbar sacral and coxal and the number of uh bones in each section so in order for there to be motion the muscle has to contract correct but it also needs to be connected to the appropriate sections of the body for there to be motion so when when a muscle is attached to a skeleton it has its origin and insertion so the origin is a point at which where it's anchored to usually this is to the part of the body where there's going to be little or no movement more this you know the the stable area so this is moving more towards the midline of the body or as I said stationary point so the proximal end the insertion is a distal away from the center body so moving away the distance so if we're looking at the bicep for instance right here I wrote it out and attaches to the choid of the scapula that's the stationary point and then connects to the muscle the tendon then is then the tendon from the muscles is connected to the forearm this is allows the flexion or flexion at the elbow so you have to have two points of uh attachment the origin and insertion where the movement is actually occurring what's what's limb moving best way to keep it simple and straightforward so when there is a muscle contraction that occurs for movement to happen it's more than one muscle firing so of course you have The Agonist the muscle that's actually causing the movement but then you have the antagonist which is the muscle that has to control slow down the movement itself so if you you you're looking at this picture here quarterback pitcher whatever throwing a ball so the tricep contracts causes the arm to extend now you have all this momentum going the arms eventually need needed to slow down you know because to prevent injury you know hyperextension of the elbow in extreme cases let's say so arm extends with a great deal of force it also needs to be slowed down so the bicep needs to be strong enough to Fire and slow down that momentum okay so that is the antagonist antagonizes slows down works against so a Agonist causes the motion antagonist slows down or prevents the motion from continuing on and on and on now though these are the two prime muscles involved in the movement itself you also can't forget the synergist muscles so they assist in the movement the the small small muscles that help hold the joint in place help lock in a solid foundation so as you know throwing it's not just out the elbow it's the whole body but just to keep it real simple so you're throwing it goes at the elbow and at the elbow to finish the movement but it also generates from the shoulder there a lot of movement as you know at the ball socket joints like I said so the shoulder has to have muscles all acting appropriately one keep it in place but also to allow it to move in the proper coordinated motion so these is one of these mus come into play these can't be pushed as hard as you could say in the chest the muscles in the chest or the bicep because they're much bigger but the synergistic muscles are a little bit smaller and usually often times neglected so it's very important when designing a program that not only are you working on the muscles muscles that cause motion uh movement itself but those that work against it so sort of like the mirror lifting don't just work on what you can see in the front you do everything in the front what should you do in the back okay and we'll get more into the program design looking on and synergist muscles and everything along the lines later on down the road so when it comes to movement everything is based off of the anatomical position in the terminology of what's going on so anatomical position as you can see here person is standing nice and Tall Palms facing forward feet forward so so we look at the front of the person here or the anterior back of the person here is the posterior now we're talking about the arm the bicep attachment here proximately distal so putting in give you more of a visual so proximal end closer to the midline of the body proximal distal distance moving away far away distance distal away from the body then you have the top and lower half of the body which is known as Superior up top inferior down there so when you talk about moving o arm is moving uh in the anterior portion of the body in the superior Direction that's how these would come into play so Superior is top inferior is bottom then you have the midline of botom body right here which separates left and right now this is a good reference points when we're talking about movement in itself so we got medial lateral so medial when you hear the phrase oh meting uh moving medially it's more moving towards the midline center of the body laterally moving away from the body so keep it real simple say this person is standing up nice and tall and he takes a step to his or her left this way they're going to move lateral all right keep it real simple now from that point where they started they take a step back to the right now they're moving immediately so real simple like say cut off this leg or a person is standing on this foot jumping right to left so when they jump to the right they're jumping medially because that's from the outside in jumping back out to left laterally I know that's getting a little confusing but just think the medial component of the leg lateral side of the leg so when you push jump to the towards the midline it's moving medially moving away from the line laterally so if you jump this way way whop that's the medial then if you jump away from the line midline of your body that's lateral okay we'll more on this in class is some can get a little bit confusing we just know if you're moving towards the middle middle of the body medially if you're moving away from the body lateral okay but the body is now broken up into three planes of motion three come we got the frontal sagittal transverse plane as you see here I'm sure we've all seen this at this point a bunch of times times so the sagittal plane is broken the GU cut right in half so you have a left and right side frontal plane you have a front and back transverse plane you're broken in the upper and lower half so this was always uh a little confusing when when I was learning it a lot of people in my class just for some reason couldn't grasp it but so here's how I broke it down so with the sagittal plane think of all these little red the red squares as a wall okay so as we know Sagal plane breaks us into left and right so think of this like a wall now it's on the side of the body sagittal for the side so if there was a wall on the left and right side of this girl right here she couldn't do any abduction movements left to right only thing she could do is movement forward to back so what usually occurs in this plane of motion flexion extension so bicep curl squat thinking more from hip flexion and extension nothing can be moved to the side then we have the frontal plane think there's a wall in front of you and back okay you can't move forward you can't move back what can you do side to side so abduction adduction so thinking more like a jumping jack motion lateral shoulder raise lateral lunge movement to the side then we have the transverse plane this is just cutting the body top and bottom top and bottom half so really anything that's occurring here if you were to put this plane through every component of the body so right here she couldn't she's basically locked in if you look at it she can't move side to side forward and back it's just more of a rotational motion that can occur now get a little bit more technical if you're thinking think laying flat on the bench arms up dumbbell y so you're more you're not going up and down side to side it's just working in that um transverse plane vertical axis okay okay so basic uh joint actions we have flexion extension abduction adduction pronation and superation so with flexion and extension when you have flexion you're looking to reduce the angle uh The Joint angle with extension you're increasing the joint angle so start here with the bicep curl so 0 to 180 degrees you're bringing the hand towards the shoulder so it's moving so you have flexion at the elbow the form is moving in a superior direction towards the shoulder recre reducing the joint angle from 180 all the way up to let's say 20° 45 degree angle we have flexion then you bring the hand back down to 180° full extension extension then if you snap the elbow you go all the way back to here now you have hyperextension which is painful so flip these numbers around so we have the knee so this would be let's say 180 Zer is over here straight line across leg comes down now we're at 90° come all the way back here now at the 20 10 degree Mark so heel going towards butt flexion heel moving away from butt extension so with the shoulder and hip sometimes this can get a little confusing so you're looking at the Joint the angle from the trunk of the body or the head let's say to the starting point so straight up and down 180 degrees so starting point up here 180 degrees same thing now with the leg moving forward this angle between the trunk and the leg is reducing so we're having flexion moving away from the trunk back now we have hyper extension or extension same thing here with the shoulder now the biggest thing when you get to the more of the bigger Mo uh levers of motion like the leg and the shoulder it's good to kind of act like you're cutting off everything that's happening below because some times you know you have uh people talk about like you know squatting they they say oh well there's flexion at the knee but they focus on this component as opposed to looking here so when you're talking about a particular joint it's best is to cut off what's below it till the next joint and just focus on this joint here so whether you had a bicep curl to a shoulder press okay don't worry about the bicep curl you're just looking at the shoulder press you have flexion all the way overhead and then you have extension movement back real simple now with abduction adduction emphasize ab and adduction is the best way to help remember this so with adduction you're adding to the body hands are coming back in so here's the midline of the body you start out abduction going away saying goodbye being gone moving away from the body abduction abduction adduction you're coming right back in so the arms were moving back in towards the midline of the body adding to the body the same for the legs abduction legs are moving out adduction coming back in then we get to the hand pronation and superation so as I said before rotation is occurring not at the wrist itself but because of the form so starting in the neutral position you open your hand up this is supination making a bowl thinking like you're looking for a bowl of soup then pronation pouring it out Palm going down pouring out so superp Nation making a bowl for soup pronation you don't like the soup you're pouring it out okay so moving on now we get into the actual muscle actions themselves the three types of muscle actions concentric Ecentric and isometric muscle contractions so concentric muscle action is a shortening of the muscle so the muscle force is greater than the resistance force so some people will be able to curl 50 pounds overcome it but now you bump that weight up to 100 pounds and can't contract it all right there's no longer concentric muscle contraction that'd be more isometric I'll get to that in a second but so concentric is being able to curl that heavy weight and actually bringing up to the shoulder Ecentric muscle action now muscle lengthens against a resistive force uh muscle lengthens because resistive force is greater than the muscle Force so best way to think of this is there's tension in the muscle but now it's extending at the same time so just think right here with the girl doing the chin up after she does a pull-up rather than just dropping down fast with no muscle activation at all she's going to lower herself down at a rate of three to five seconds so she's controlling her desent that muscle firing of the bicep is Ecentric so the muscle still tense but it's controlly actively elongating slowing down the M motion movement isometric contraction is there's no change in the muscle length there is tension developing but the force B of the muscle isn't enough to overtake the resistive Force okay so it could be for the pullup it's two two areas where this could occur either at the top of the movement now the muscle's Contracting it's not going up it's not going down she's just holding that or at the base of the move she's trying to pull up but it's not she can't pull herself up because maybe she's too heavy with the weight Bel or anything on there so to break it down real simple so there's three phases of the lift of the pull-up we're just going to dissect the pull up right now so hanging at the bar pulls herself up that is the concentric phase of the muscle of the movement bicep is shortening tension in the muscle pulling yourself up at the top of the movement holding it for two three seconds let's say muscle is now no longer lengthening or shortening this is the isometric phase of the lift now the final third phase of lift is the lowering The Descent as she controls herself down in a rate of let's say 3 seconds this is the Ecentric component of lift slowing down there's still tension in the muscle there's no slack because she's engaging the muscle the whole time Ecentric muscle action is key in preventing injury often times especially in a lot of field sports okay so all three muscle actions are present in movement especially in sport now when we're designing a program is this something that should be looked into should we target these specific types of movement the answer is yes most likely targeting each component of lift not only helps educate the body more but helps reduce the likelihood of injury you break it down to a sport like football lacrosse soccer you have acceler you have acceleration and deceleration a lot of Rapid change of Direction all right so you get a very explosive powerful athlete let's just say a running back because the picture's here and I'm not favoring one sport of the other but we can all relate or soccer you sprint forward 10 meters 20 yards as hard as you can Defender is in front of you you now have to slow your speed in order to get around that person now if you can generate so much force so much power but you can't handle it you're not going to be as efficient or effective in that rapid changeing Direction so a lot of times programs designed to make you more explosive more powerful but can you handle that can you handle that power can you can you contain it so though concentric muscle action is just as important to execute a movement Ecentric is just as important to control the movement so if you're looking at the running back so he's running forward gets to his Defender he needs to slow down slightly if not all the way in order to stop plant and make a cut if he's not strong enough the muscles his hamstrings and glutes don't properly or can't handle that amount of momentum he's generating that's where an injury can happen knees Buckle in blown out ACL something along those lines being strong enough to slow your descent effectively prevents the over overcommitment or over the flexion hyperextension of any of the joints and tears of muscle so it's good to train those two components separately concentric Ecentric this will happen we we'll talk more about this a little bit later on in the uh course but for right now I just want to give you a little taste finally the isometric component this is where you actually come to a complete stop before you accelerate or explode out of that movement so you break down you stop now you got to decide that microsc left or right the amount of time you can spend the amount of time you spend in the isometric State dictates how fast you're going to come out of it you know the more the longer you're in the isometric State the more power you're going to lose so this comes down to agility the rapid change in direction if you can limit the amount of time you are in that isometric State the less power you're going to you you lose and save to actually get you out of it so when designing a program knowing what the movements are in the sport what's needed to what what muscles are needed for the actual movement itself what are the muscle actions in that movement whether it's pitching throwing lacrosse Soccer kicking it's good you need to know everything that goes into the motion itself at the joint and then understanding what planes of Mo planes of motion you're going to be working in when desig the program the biggest thing when designing a PR program is keeping it bounce you know push pull up and down front and back all these have to come into play when designing a program it's not so much all the time how strong you can get the person like how much they can lift strength is being well balanced having the range of motion the flexibility and the ability to perform over and over again with with less likelihood of injury it is what makes sound program good sound in that sense so when design a program don't just look at like how much how can I make them bigger and stronger look at how you can balance the whole athlete out looking to reduce the likelihood injury because everything else will just fall into play and help and work together to make them stronger okay this boils down to the whole coaching philosophy caring about your athletes putting their their health their priorities ahead of your own you want to protect them like they're young keep it safe keep them learning keep them progressing forward but by designing a balanced program with the safety mind everything else will come into play