Invasion games are simply defined by attempting to get an object into a goal or area that is defended by an individual or a team. These games are commonly played with a marked boundary or territory. Each team are required to pass the object between themselves to set up an opportunity to evade and gain territory of the opposing side to score a goal. Common invasion games are Basketball, Soccer, Lacrosse, Hockey, Netball etc. In this slide I will be discussing and critically breaking down the biomechanics of a selected specialised movement skill from Basketball. Two individuals 3-point shot will be broken down, one being an autonomous level NBA play Stephen Curry this is the last of the stages of learning. At this point the skill is well learned. The athlete performs the skill automatically without having to focus on execution. And the second will be myself who is associative stage. At this stage the athlete understands the fundamentals of the skill and is in the process of refining the skill. They experience fewer errors and can detect some of them on their own.
Specialised movement skills are skills that have been refined and combined to form sport skills. These skills are task specific, whereas fundamental movements are not but lay the foundation to specialised skills. If an individual does not develop and become efficient in the mature level of fundamental motor skills, this has a direct effect on the ability to perform specialised movements. Specific aspects are needed from the previous stage to progress onto a specialised skill however progress does not go one phase to another on a linear line. An individual is not required to be mature in all fundamental movements before advancing to other stages just certain aspects. Specialised movement skills can be broken into three phases. Phase 1 specialised movement transitional stage where it’s the individuals first attempt to refine a combined mature movement skill. This leads you into phase 2 where the individual becomes more aware of personal physical assets and limitations, focusing on certain areas of the sport. There is strong emphasis on improving efficiency, constant practice is key to development more refined skills. Phase three is the stage where an individual will reduce the scope of their athletic pursuits by choosing activities to engage in regularly. Examples of specialised movement skills in basketball is;
- Jump shot
- Lay up
These specialised skills are an extension of fundamental movement skills learnt from a young age. Fundamental movement skill are motor patterns that are considered the foundation of the more specialised and more complex motor patterns to enhance the specialised skill used in sport or recreational activities. Fundamental motor skills comprise one level in the continuum of motor skill acquisition. Children at the fundamental motor skill stage are building upon previously learned movements and preparing for the acquisition of more advanced skills. For example, throwing in softball and cricket, the baseball pitch, javelin throw, tennis serves, and netball shoulder pass are all advanced forms of the overhand throw. The presence of all or part of the overhand throw can be detected in the patterns used in these sport specific motor skills.
The principles of play are the fundamental strategies that a team uses to effectively adapt to any tactical situation during a game. They consist of concepts that coaches use to focus their team’s objectives and to evaluate the performance of their players on the field. Looking further at the principle of play within basketball would Include setting up plays for attack, using defence strategies for defending, creating, defending and exploiting space, attacking space and scoring. This could be seen in a game of basketball by using proper stance, knee bent, stable centre of gravity when defending maintain strong balance. Playing man on man defence to eliminate chances of opposing team creating space and scoring. Always run in pairs in attack to create space by using screens.
Movement strategies refer to a variety of approaches that will help a player or team to successfully achieve a movement, outcome or goal. Basketball is fundamentally a game of effective spacing and movement that requires precision passing, communication and team chemistry that helps synchronize the movement of the player with the ball and his/her teammates without the ball. This is where technical strategies are introduced to perform plays in the most efficient way. Possible strategies a team could implement are playing and moving on the perimeter, receiving pass on the perimeter, attacking the basket off a pass, moving the ball in pairs, pick and Roll.
To allow a team to perform at the highest level possible or an individual best, they need to be aware of body concepts. Understanding and knowing how to manipulate these concepts are critical. There are three critical concepts to understand. Body awareness is highly influenced by proprioceptive processing, the sensory information one receives from the movement and force of muscles and joint groups. Spatial awareness is the ability to be aware of oneself in space. It is an organised knowledge of objects in relation to oneself in that given space. Spatial awareness also involves understanding the relationship of these objects when there is a change of position. Effort Awareness is the ability to develop a conscious recognition of one’s body movements while performing various physical activities (Carson, 2001).
Constraints are the boundaries that influence the movement capabilities of an individual. Three constraints have been identified and broken down to understand, individual constraints, task constraints and environmental constraints. Individual constraints: The unique mental and physical abilities of the individual that effect their decision making and movement patterns, and that can be displayed during performance. Task Constraints: The rules, equipment and goal or purpose of an activity that limit the decision making and movement patterns that can be displayed by an individual during performance. Environmental constraints: The social or situational factors that limit the decision making and movement patterns that can be displayed by an individual during performance.
My selected specialised movement sequence in basketball is the 3-point shot. This is a field goal in a basketball game made from beyond the three-point line, a designated arc surrounding the basket. A successful attempt is worth three points. This is achieved by using specialised movements to create space between the attacker and defender, successfully rise above the defender eliminating the possibility of being blocked and score the points. A 3-point shot or jump shot can be broken into four separate phases. In order, counter movement, initial take off, release and landing. We can use these phases to break down the specialised movement into subroutines to effectively create the best opportunity to consistently get the best jumper.
Hip Displacement – the shooter should not get too far down because then there will be an excessive amount of overlap of the cross-bridges. Depending on the height of the player, anywhere from 15-40 cm is a regular amount of hip displacement. The athlete will lower themselves towards the ground through hip, knee, and ankle flexion to create optimal force from the base going up.
Vertical height of jump – It’s an important part of a jump shot, too, especially in a game situation. An obvious reason would be because of the defender. The higher you can jump, the less he’ll be able to affect your shot.
Elbow Flexion – The flexion in your elbow is one of the ways you generate force behind your jump shot. Flexing your elbow is a countermovement to the upper body, much like the bend of the knees is for the lower body. Without elbow flexion, you would have a push shot (or a shot using all arm) which is exactly what coaches teach you not to do at a young age.
Wrist flexion/extension – Wrist extension/flexion – The majority of force generation (at least for professionals) comes from the movement of the wrist. It creates a back spin on the ball. This back spin increases the chances that the shot will go on. If the shot happens to hit the back of the rim or the backboard, having this back spin on the ball with cause it to directly shoot downwards because it will decelerate the ball by using friction to cut down on the ball’s velocity.
Elbow extension – The suggested angle of elbow extension is from the previously mentioned 90 degrees of flexion to full 180 degrees of extension. The suggested angle of wrist extension is also ninety degrees, or as far as your wrist can extend. During the follow through, it is optimal for your elbow to fully extend and the same for your wrist.
Hip displacement from initial take-off – Focusing on landing where you initially took off creates a sense of balance, so the focus is more on the arms being the main contributor to the actual shot of the ball. However, it is nearly impossible to land exactly where you took off, so most professional basketball players land within a five to eight-centimetre radius of where they took off.
Notice Stephen Curry has both feet parallel pointing toward 10 o’clock to allow shooting of hip and elbow properly align with the rim in one vertical plane. I have also noticed he doesn’t jump very high, probably equivalent of jumping rope. Without a huge jump it allows him to replicate the height without fear of fatigue in the end game. A slight rotation in the air, this is a natural movement that comes from the right shoulder moving forward on the release in the air. A tendency if stopped would cause unnecessary tension in the core and would affect releasing a smooth and relaxed shot. Steph catches the ball close to his chest eliminating the extra movement of bringing the ball back to his chest. When the ball comes from the left like in this clip you can see he catches it right in the alignment of shot allowing him to go up in a smooth motion. Once he catches it, he uses a short dip to get rhythm and power, without doing this he would have to generate more power through his arms and wrist in return losing accuracy. You can see his elbow crease is levelled with his forehead so the lower set point does not mean the shot trajectory will be to low. In fact, it’s the motion that is the key to his one motion shot. By using a one motion shot he is maximising all the power generated from his legs and dip into a fluent release that is always straight. In the clip you will see he has already started the bend in his legs before the ball begins to move up. This means his already in the correct position to start straightening his legs before the ball has already moved up. You can see that the elbow and wrist lock at the same time. This ensures consistency once learnt. Although Curry does some things in his jump shot incorrect to the average coach these are tendencies that would change his jumper making it worse like his tendency to land forward after his shot. This gives him more distance allowing him to shoot further from the arc. Also, Steph covers his right eye on his one motion up to release point. Traditionally coaches are taught to correct it, but curry keeps his eye on the ball the whole time possibly helping him focused on the biomechanics of his shot. Keeping his laser focus.
From analysing a short snippet of a in game 3 point shot of myself, I have noticed many incorrect tendencies that need sharpening to progress onto the next movement stage. From analysing this data, I picked up that I started the upward motion of the ball to far in front of my body. This created an off-balance jump shot; it also effected the alignment through my hips through to my arms. The 3-point shot was performed off the dribble, like any agility-based movements your base of support is smaller compared to still position. Having a weak base of support made me land 10-15cm Infront of where I first left off. I also noticed my elbow and wrist release was not the same. This is due an organismic constraint. A previous injury I’ve had on my wrist resulting in surgery. My wrist doesn’t have full flexion, and this resulted in a over extension of the elbow to make of for the lack of force my wrist will contribute. You can see the wrist flick if late and not synchronised with elbow and peak of the shot. These tendencies effected my whole shot as it was not a smooth flowing shot. Momentum was not used through the shot. Although I was able to make the shot it’s not consistent. However, there were a constraint that I was able to understand and manipulate to my advantage. From receiving the pass, I showed good vision and was able to keep my eyes locked onto the defender pulled while he was back peddling to catch his defence of guard.