What Influences an Athlete’s Motivation

Hannah Franklin EXSC 201 Introduction to Health and Human Performance Annotated Bibliography December 6th, 2018 1. Tanikawa H, Matsumoto H, Harato K, etal. Female recreational athletes demonstrate different knee biomechanics from male counterparts during jumping rope and turning activities. J Orthop Sci. 2014. 19:104–111. The purpose of this article was to compare the knee biomechanics among men and women when each gender group performed the activity of jumping rope and turning activities. The main goal of this study was to demonstrate the different risk injuries between men and women in the knee biomechanics of landing. Researchers created the hypothesis that men and women would differ among their movement techniques as they performed several athletic tasks. Researchers assessed twenty recreational athletes, with ten of these participants being men and the other ten participants being women. These twenty athletes were evaluated by completing several different task such as jumping rope, backward running, side running, side-to-side running, side-to-forward running, inside turning, and outside turning. In order to have an effective study, researchers made sure their participants were all young and healthy recreational athletes. These participants had to meet the certain requirements such as being involved in at least one recreational sport per week. They also had to have no complaints about their lower extremity within the past 6 months as well as have no injuries or surgeries to their lower extremity. Before the experiment, protocols were approved by the ethics board and participants also granted the researchers with their permission. Researchers performed a five step method in order to evaluate their participants. The first step was considered skin marker placement and motion analysis system. Participants had retro-reflective markers placed on their lower extremity such as bilateral anterior superior iliac spines; bilateral iliac crests, L5/S1 joint line, frontal and lateral thigh, etc,. The next step subjects had to proceed was the athletic motions. They were required to use their dominant leg while they were performing the tasks. For example, participants had to complete an inside/outside turning activity. They were told to run forwards toward the force plate, hit the target with their dominant leg, turn a full 90 degrees around, and then continue to run in the direction they originally started from. Then the step of the calculation of joint kinematics and kinetics took place. Researchers used a software known as Q-Trac to convert the results onto a computer in order to evaluate the data. Researchers then moved onto the step of evaluating the muscle strength testing by utilizing the Biodex System III dynamometer to get the weight of the body’s quadriceps and hamstrings. The final step was statistical analysis, in which researchers compared males to females using one-tailed t tests. The results of this study was that females have a lower muscle strength among their quadriceps and hamstrings compared to their male counterparts. Therefore, the force of the knee anterior was greater than males, especially in the activities such as jumping rope, side-to-forward running, inside turning, and inside/outside turning. Females also showed to have a higher knee flexion and abduction angle during jump rope. However, they showed to have a lower knee flexion angles during side-to-side jumping. In conclusion, researchers claimed that females experience different knee biomechanics compared to males, especially is the specific activities of jump rope and turning motions. Researchers believe that this factor is simply because females perform athletic activities in a different manner than males tend to perform the same athletic activities based off of their movement techniques. With that being said, subject’s movements techniques are based off of their motor controls, anatomical structures, and physiological characteristics. Overall, this research article is a solid study that is hard to critique. Honestly, the only adjustment I can think to suggest would possibly be to gather more participants so that then the results would seem more fuller and precise by evaluating additional participants. However, even with twenty subjects I still think the study is just as effective. Researchers used the activity of jump roping which demonstrates the ideas of landing biomechanics between men and women. The task of jumping vertically, as one does while jump roping, is effective when studying knee biomechanics because it exemplifies the stress that occurs on the ligaments and tendons when the subject lands. The most common ACL tears are simply caused by one landing improperly on all their significant amount of force that is released one they touch the ground. Therefore, this study was designed in order to demonstrate the biomechanics of the knee and how the body responds to stressed landings by practicing an activity that can also be associated with common ACL tears, such as jump rope. With all of this being said, this study ultimately illustrates the differences between the biomechanics of athletic tasks among males and females. Researchers mainly utilize the activities of jump roping and turning exercises in order to support their thesis. This study is helpful to those in the medical field such as physical therapist, trainers, and those in pre-habilitation. Throughout rehab, my physical therapist helped me gain my muscle strength back in my ACL through exercises like leg lifts, planks, one legged hops, etc,. These exercises can also be utilized in order to help one prevent ACL injuries. Therefore, the outcome and information included in this study will help me to prevent further ACL surgeries now that I am aware of the risk that women have a higher knee anterior force. Personally, this especially will be effective for myself when I recover from my ACL surgery because I know the biomechanics of the knee and how to avoid such risk and danger of tearing it again at all cost. Ultimately, this is a well put together study that not only compares the differences in knee biomechanics between gender but also explicitly explains the risk of common knee injuries. 2. Myer GD, Hewett TE, Ford KR, etal. Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes. Am J Sports Med. 2005. 33(4):492–501. The purpose of this article is to demonstrate the risk in females athletes when it comes to the biomechanics of pivoting and jumping during sports activities. The main goal of this article is to discuss the effects that landing biomechanics specifically has to the ACL. This article mainly stresses the importance of understanding as well as practicing neuromuscular control factors as to how it can help improve ACL knee injuries, especially in females. Researchers created the hypothesis that female athletes who were pre-screened but later faced an ACL injury would maintain a lower neuromuscular control and higher valgus joint loading which would ultimately result in their ACL tear. Researchers decided to perform a cohort study for this experiment. They chose 205 young female athletes who participated in sports such as soccer, basketball, and volleyball. These subjects were screened during their pre-season by a 3D biomechanical analysis machine. Subjects were observed through two soccer seasons in the fall and one basketball season in the winter. Nine of these female athletes faced an ACL injury during their season with seven occuring during soccer and the other two occuring during basketball. Those participants who got injured all had comparable features such as their age, height, and weight. Subjects, as well as their parents, had to give their consent to the Cincinnati Children’s Hospital Medical Center Institutional Review Board. After it was approved, researchers began to record their subjects basic data like age, height, weight, and dominant leg. Subject’s knee joint flexion-extension and adduction-abduction were evaluated by a sequence of drop vertical jumps, also referred to as DVJ. However before the participants were tested, they had twenty-five retro-reflective markers placed on their lower extremities and shoulders. The markers were then replaced with raw markers and monitored on an EvaRT software which then processed the markers into global 3D coordinates. Females were then instructed to stand on top of a 31 cm high box with their feet 35 cm apart. Next they had to drop down from the box. Once they hit the ground, they were required to do a maximal vertical jump as they raised both of their arms into the air. Each subject’s results were recorded based off of their three most successful attempts. The study also utilized eight high-speed cameras in order to record the motion analysis. The cameras transported this information to the computers that store all the data from the study. The ground reaction force was determined by two force platforms located below the box at 8 cm apart. The data from the markers was then evaluated through a low-pass Butterworth digital filter system and then sent to another custom software known as Kinrak in order to evaluate the knee flexion-extension and adduction-abduction throughout the experiment. As the results were being processed, subjects were being monitored by athletic trainers in order to keep track of their possible injuries during this waiting time. The results of this study were concluded through the data from the markers that were evaluated by a low-pass Butterworth digital filter system. Theses results were then sent to another custom software known as Kinrak in order to evaluate the knee flexion-extension and adduction-abduction throughout the experiment. Ultimately, nine females proceeded to rupture their anterior cruciate ligament. These nine injured athletes demonstrated different posture and loading techniques throughout their knee during this experiment. Therefore, subjects who became injured maintained a higher knee abduction angle of 8.4° versus those who remained uninjured with a knee abduction angle of 1.4°. Injured subjects also had a 10° lower flexion in their knee compared to the uninjuries subjects. Yet, no difference was determined in the knee flexion angle and peak knee flexion angle between the injured and uninjured. The injuries results consisted of six dominant legs and three non-dominant legs. Also, none of these nine injuries were caused on impact with physical contact, but rather they did not involve any contact at all. The knee abduction angles and moments form a sensitivity of 78% and specificity of 73% when it comes to anticipating a rupture in the anterior cruciate ligament. Overall, the main element that affected ACL injuries during this study is the knee abduction between the subjects. In conclusion, knee motions and loading biomechanics have an influential impact on females tearing their ACL. After the study, females who managed to tear their ACL revealed characteristics of altered neuromuscular control factors. Subjects who became injured demonstrated different biomechanics among their lower extremities through the experiment which was prior to their injury compared to the uninjured subjects. Overall, this study does have points in where it would be criticized. For example, researchers did not control variables throughout their study such as foot pronation, blood hormone levels, femoral notch width, etc,. Also, if the time period of the study would have been extended then the results could differ and ultimately be more beneficial. These female athletes have been involved in sports for years before the study was completed. Therefore, if these subjects have encountered several valgus beforehand then it could have taken years before their anterior cruciate ligament actually erupted. Also if the study was extended, it would have allowed one’s neuromuscular status to be adjusted over their injury-tracking period. I also thought it was interesting how they used female athletes who participated in sports such as soccer, basketball, and volleyball. However, no volleyball players seemed to be at a high risk for an ACL injury, or at least no volleyball players resulted in this factor. I also would have liked to see researchers compare male subjects to female subjects, rather than just using females during their study. Despite the critiques, this study does have some effective research included throughout. This article displays a message not only for athletes, but also any department involved in the medical field. It alerts readers of how critical it is those who are physically active should practice their performance on their neuromuscular control and their valgus loading of the knee. It also provides information to physicians, physical therapist, clinicals, and other medical departments on the importance of the high-risk and dangers that come along with ACL tears. Therefore, medical departments are aware on how they can help prevent their patients, as well as themselves from encountering this injury. Since I am grouped in with the nine subjects who have had an ACL injury, I plan to use this information by doing training exercises that will ultimately strengthen my leg. Therefore I will hopefully and eventually be able to regain some of my muscles joint stability back. For future research, I would recommend studying and calculating subjects developmental characteristics such as their age, coming of age, growth, and maturation to see how it affects the factors of their neuromuscular control. With all of that being said, this article is provides very informative aspects on females knee biomechanics, especially related to the anterior cruciate ligament.