Human Movement Analysis Multimedia Report

Human Movement Analysis Multimedia Report

Introduction: Basketball is a game played by two teams consisting of five players. The game is played until one team commits a foul, when this happens the fouled player is given an attempt at a free-throw (Piano et al, 2013). A “free-throw” is an attempt to shoot from the free throw line, this is awarded to a player after a foul has been committed. A free-throw is considered to be one of the most important timeframes in a game and coaches frequently refer to their team’s success or failure from free throws (Schulze, 1981).  A successful free-throw shot requires excellent body mechanics.  In order to be successful when attempting a free-throw, a player should go through the following phases.  Phase 1, “The Preparation Phase”, the player will align themselves at the free-throw line where they feel comfortable with their feet shoulder width apart (Wrisberg and Anshel, 1989).  Phase 2, “Action and backswing phase”, in this phase, the player has typically 50% of their trunk leaning forward, hip and knee flexion, while the ankles are dorsiflexed.  The shoulder, hip, knee, and ankles are lined vertically as the player prepares for the backswing phase, this is depending on whether a person is right or left handed (Hudson, 1982).  Phase 3, “Follow through phase”, the player is producing force through their body.  The ball is being projected upwards and forward towards the basket by force. The player’s legs and torso should be extended, and their dominant hand should be out straight. During the follow through phase the basketball is placed in front of the body with their shooting hand directly behind the ball, while the non-shooting hand should have little contact with the ball and only be used for balance.  The shot begins when the torso moves to a vertical position and the ball is held at approximately shoulder level.  Moments before this phase is over, the player’s knees should be in maximum flexion (Knudson, 1993).  Phase 4, is the “Instant of the ball release.”  The player cannot change the ball position once it is released and in flight.  The trunk of the player should be vertical and should stay rigid and have no movement during the release of the ball and during the follow through (Penrose & Blanksby, 1976).  At the exact instant that the ball is released, the torso and legs of the player should be fully extended. The shoulder of the dominant hand should be in a flexed position. The player’s elbow should be close to full extension this is how we know that the elbow joint has contributed to the movement of the ball.  When the elbow joint has full range of motion there is a better relationship between scoring free throws (Stankovic, Simonovic & Herodek, 2006).”  The position of the wrist should be between full flexion and full extension to ensure that the dominant hand that is moving at its best when the ball is being released. Wrist flexion provides the release of the ball this will contribute to the angle of the projection of the ball (Hess, 1980).  Phase 5, “The angle of the shot” is noted after the ball leaves the shooter’s hand. The angle when the ball is released should be between 50-55 degrees (Brancazio, 1981).  The higher ball is thrown the more requirement for a larger range of motion from the shooter’s legs and the dominant shooting arm.  Phase 6, is the final phase of the shot is the “follow-through phase”, all the joints of the body move through their stages to release the ball to its best efficiency. In the follow-through phase, the legs are fully extended. The trunk is in vertical position.

Aim: The overall aim of this projectis to analyse the movement patterns of a free throw between an amateur and a professional and to give relative feedback to improve their technique.

Methods: The participant was 21 years old and male. He has 3 years of basketball experience while playing in secondary school. A free throw using his own personal technique was used in an indoor gym with artificial light. The technique that was used was a one-push hand shot. The participant’s dominant hand is the left hand. The participant was not suffering with any injuries during the analysis and had not suffered with any in the last 2 years previously. The distance between the free throw line and the basket was approximately 15 feet (front view). The distance between the side line and the participant was 18 feet (side view). The basket was put up for this recording as it is on wheels in the gym and not permanently stationed to a surface. The rim height of the basket was 10 feet (irrelevant to this particular study). The camera that was used was a Nikon Coolplix 59600. The camera was sitting on a universal tripod near the left sideline and under the basket on the end line for the front view. The participant had a trial run on each side to make himself familiar with the ball and new basket. As the skill was being performed it is was simultaneously being recorded.  The participant was recorded 5 times through a side view and 5 times taken at a front view. The player was recorded 5 times in slow motion (400/4) and 5 times in normal speed (1030/80) both side view and front view. He was instructed to take 5 consecutive shots to be able to choose the best quality video from the individual.  After recording participants movement, the video was transferred to a memory device and then uploaded to a video analysis system software called Dartfish. Multiple trials of the data was collected in Dartfish in order to analyze angles and time points in the movements being measured. The equipment used was a basketball, tripod, camera and markers. A review of feedback was given to the participant and video analysis along with techniques to improve their free throw were given. Dartfish was used as the video analysis system software to easily be able to get access to heights, angles and distances of the participant. All phases of the free throw were examined through dartfish and relative feedback was given.

Results:

Figure 1.

The player shot 20 free-throws missing 8 and achieving 12 combined as a free throw percentage of 60% as seen in Figure 1 above. This is quite a good score considering there is some implication with the biomechanics of the participants free throw.

Strategies to improve technique.

Figure 1:       Figure 2:

As seen from Figure 1. the player does not place his fingers along the curvature of the lines of the ball. This will affect his backswing and the accuracy of the ball. The player also holds a lot of the ball in the less dominant hand (right hand), this hand should only be a rest for the ball as the left hand should be directly at the back of the ball and the right hand will serve to make sure the ball is stable on the hand. Hartley & Fulton, (1971) states that the shooter should spread the fingers, so they will have better control of the ball, and place the fingers so they are directly behind the ball and not on the side of the ball. Figure 2 shows how the ball should be held properly although the shooter in Figure.2 is right handed the participant should be holding the ball directly like this but using the opposite hands.

Figure 2:

The individual applied an adequate amount of force into the ground by flexing at the hip, knee and ankle joints.  As seen here in Figure 1, the athlete is bent at a 90.5° angle in the flexion stage of the backswing throw. Although the force is correct in this the placing of the arm position is incorrect. During the backswing phase the arms should not be placed over the head yet to shoot the ball. The ball should be in line with the shoulders. Having the arms this high at the beginning of this phase can cause problems with the backswing phase and could also lead to balance loss. Therefore, the player needs to consciously bring the arms down lower during the backswing phase and then release up higher when shooting the ball.

Figure 4:

Figure 5:

Another issue that this player is having is that they have no trunk flexion during the backswing phase. When the required trunk flexion for this stage is not met their ability to load from the legs will be decreased and their ability to use trunk extension may be lost. The knees should be flexed close to 90 degrees, the trunk should be flexed close to 50 degrees from vertical (Oddsson, 1988). Overall, the participant may lose the full contribution to the shot through leg extension that would be achieved from a deeply flexed position. A deeper trunk flexion will also produce more hyperextension at the player’s neck, so they can retain more focus on the rim of the basket. No flexion of the trunk will also decrease the participants ability to load the legs for the shot and therefore might end up losing full contribution of leg extension from the deeply flexed position to free throw. The ball should also be brought up to shoulder level prior to the release. This individual is not doing this during the backswing phase. The ball is over his head as seen in Figure. 4. This will cause problems with the backswing phase as it will not be one swift movement from the preparation stage to the release stage. The player needs to improve trunk flexion by bending over more into a squat like position when taking the free throw.

Stretching of the lower limbs and different shooting techniques can be used to improve this participants performance.  The stretches should focus on parts of the body such as quadriceps, hamstrings, and calf muscles in the lower limbs, practised before shooting drills. This will help the force needed from the lower limbs. One of the limitations to this study was not getting a video recording of the player shooting the ball into the basket. While it was mainly the technique of how a free throw was taken that was looked at through the study it would have been informative to see if the player made the shot or not. While the results from the shots were written down (See Fig. 1) more measurement could be made if the basket was in the video. The relative height of projection would also be able to be measured with the basket in the shot. This would have been interesting to know since the participants arms and hands were laced too high during the backswing phase (see Fig 3 + 4) this could have greatly affected the height of projection of the ball.

Conclusion:

In conclusion to the study the participant has 3 main areas that they need to work on that are highlighted above. With much practice and feedback the biomechanical techniques of their movements should improve.

See link to dartfish clip https://dartfi.sh/yCnN9923gCa

References:

• Brancazio, P. J. (1981). Physics of basketball. American Journal of Physics, 49(4), 356-365.
• Del Piano, C., & Leigh, S. (2013). Basketball Free Throw: A Written Technical Report.
• Hartley, J. W., & Fulton, C. (1971). Mechanical analysis of the jump shot. Athletic Journal, 51(7), 92.
• Hess, C. (1980). Analysis of selected mechanical factors that contribute to vertical jumping height of four basketball players. Unpublished doctoral dissertation, University of North Carolina.
• Hudson, J. L. (1983). A biomechanical analysis by skill level of free throw shooting in basketball. In ISBS-Conference Proceedings Archive (Vol. 1, No. 1).
• Kaya, D., Callaghan, M. J., Donmez, G., & Doral, M. N. (2012). Shoulder joint position sense is negatively correlated with free-throw percentage in professional basketball players. Isokinetics and Exercise Science, 20(3), 189-196.
• Knudson, D. (1993). Biomechanics of the basketball jump shot—Six key teaching points. Journal of Physical Education, Recreation & Dance, 64(2), 67-73.
• Penrose, T., & Blanksby, B. (1976). Film analysis: Two methods of basketball jump shooting techniques by two groups of different ability levels. Australian Journal for Health, Physical Education and Recreation, 68(3).
• Schulze, P. (1981). Concentration—key to free-throw success. The Basketball Clinic, 13(6), 6-8.
• Stankovic, R., Simonovic, C., & Herodek, K. (2006). Biomechanical analysis of free shooting technique in basketball in relation to precision and position of the players. In XXIV International Symposium on Biomechanics in Sports, Salzburg, Austria.