The purpose of this study was to analyze the effects of changing a saddle height to a scientifically recommended position on cycling economy for competitive cyclists. Participants completed one maximal effort graded exercise test and two sub-maximal 70% economy trials, one at the cyclist’s original saddle height and the second at the saddle height corresponding with a knee flexion angle of 25° at full pedal extension. Due to experimental error and equipment failure heart rate became the main performance measure and cycling economy tests were conducted at an average of 84.4% of heart rate max. The results revealed no apparent differences in performance between the recommended and original saddle height. However, 2D analysis of dynamic knee angles revealed that at the 25° knee angle condition, knee angle increased by an average of 16.1% from the static position (average dynamic knee angle = 29.02±4.61°). Dynamic measures (32.59±4.88°) taken during the original angle tests were only slightly augmented compared to the static measure (31.5±2.18°). It is possible based on this trend that a difference in performance values was not present because the change between the original angle and the experimental angle was not substantial. Additionally these findings suggest that cyclists adjust to these acute changes in saddle height by altering other kinematic variables in an attempt to find a comfortable position and perform maximally.

The purpose of this study was to determine if there were asymmetries in ground reaction forces (GRF) between dancers and non-dancers, and to see the effect of GRF on external (ER) and internal rotator (IR) strength. Subjects performed double- and single-legged jumps on a force plate with a motion capture marker system attached at anatomical landmarks, and then had strength and range of motion (ROM) of their internal and external rotators tested along at degrees of hip flexion. There were no significant differences in GRF between legs for all subjects involved. However, stronger hip ER was negatively correlated with vertical GRF (z-axis), positively correlated with anteroposterior (y-axis) GRF, and higher mediolateral (x-axis) GRF from double-leg trials was positively correlated with knee abduction. Thus, future studies should further investigate GRF broken into axial components as well as the time to peak GRF to determine any relation of these factors to knee valgus and ACL injury risk.

Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Because of this, many new types of equipment have been created in an attempt to induce instability, such as the COR Bench. 15 males and 7 females between the ages of 18 and 30 were recruited for the present study, which tested two forms of instability: using one dumbbell rather than two, and lifting on the COR bench compared to a flat bench. Thusly, EMG was used to measure muscle activity in four separate conditions of unilateral bench press movements: on a flat bench with one dumbbell, on a flat bench with two dumbbells, on the COR Bench with one dumbbell, and on the COR Bench with two dumbbells. Results indicated that lifting with one dumbbell compared to two dumbbells on the flat bench significantly increased muscle activity across all four muscles being analyzed (pectoralis major, p = .005; middle trapezius, p = .008; external obliques, p = .004; and internal obliques, p = .003), but lifting with one dumbbell compared to two dumbbells on the COR Bench only significantly increased muscle activity in the middle trapezius (p = .001), external obliques(p = . 032), and internal obliques (p = .001). The only muscle to exhibit a significant increase in muscle activity when going from one dumbbell on the flat bench to one dumbbell on the COR Bench was the middle trapezius (p = .010). These results imply that the COR Bench itself does not increase muscle activity as much as switching from two dumbbells to one dumbbell, regardless of the bench being used.

The following study evaluated the effectiveness of the COR Bench, to determine if its unstable surface allows for both greater range of motion and greater tendency towards co-contraction, in comparison to a traditional flat bench. An initial session assessed the 19 participants’ (age, 22.364 ± 2.480 years; mass, 77.850 ± 18.328 kg; height, 1.787 ± 0.0923 m) current one- repetition maximum strength levels for the unilateral chest press. Four different conditions were used to test the kinematic variables such that each participant completed 5 repetitions of unilateral chest presses at 70% of their max with one and two dumbbells on both the COR Bench and traditional flat bench. Differences in ROM were evaluated by measuring an angular representation of the shoulder complex. Levels of co-contraction were determined by analyzing the middle trapezius EMG. The results indicate a significant difference in ROM between the conditions (p = .00); specifically, a greater ROM during the one dumbbell condition versus the two dumbbell condition on the COR and the flat benches (p = .002, 0.001 respectively); greater ROM with two dumbbells on the COR bench compared to the flat bench (p = .022). The middle trapezius EMG data showed a significant difference in co-contraction levels between conditions (p = .00); specifically, a greater co-contraction during the one dumbbell condition versus the two dumbbell condition on the COR and the flat benches (p = .001, 0.008 respectively); greater co- contraction with one dumbbell on the COR bench compared to the flat bench (p = .010). This lends support for the future use of the COR bench as a means for more efficient exercise through a full range of motion; however, it also suggests that more practice is necessary to master the movement on the bench to decrease co-contraction activity.

The study was based on research done on the achievement goal theory. The purpose of the study was to discover if goal orientation would change after manipulation of the motivational climate. The study also was conducted to find if there was evidence of gender differences in motivational climate preference and satisfaction. These findings may help to provide a fun and motivating environment for all children in a physical activity setting. Investigators manipulated the climate to present lessons that were more task orientated in nature (mastery climate), and lessons that were more ego oriented in nature (performance climate). Participants consisted of girls and boys ages eight to ten years old (M = 9.5) recruited from a fourth grade P.E. class (n=42, females=20, males=22). The children participated in activities in a mastery and performance climate. The Task and Ego Orientation in Sport Questionnaire (TEOSQ), the Athlete in Sport Questionnaire (ASQ), and the Perceived Motivational Climate in Sport Questionnaire 2 (PMSQ-2) were administered. From the data it was concluded that there were no gender differences between baseline task and ego orientation scores. The children also did not perceive a performance climate after the performance climate intervention There were no gender differences in satisfaction following the mastery climate and the performance climate. The children's task and ego personal goal orientation scores on the PMCSQ-2 did not change following the mastery climate or the performance climate. There may be an absence of a gender difference in satisfaction and possessing either a task or ego orientation due to the factor of age. The student's regular PE coach enforces a mastery climate in their class, which may explain why the participants did not perceive a performance climate during the performance climate intervention. There were some methodological hurdles and problems in conducting the present study, which may account for the results.

Although the sport and exercise of running has a great amount of benefits to anyone's health, there is a chance of injury that can occur. There are many variables that can contribute to running injury. However, because of the vast amount of footsteps a frequent runner takes during their average run, foot strike pattern is a significant factor to be investigated in running injury research. This study hypothesized that due to biomechanical factors, runners that exhibited a rear foot striking pattern would display a greater incidence of chronic lower extremity injury in comparison to forefoot striking counterparts. This hypothesis would support previous studies conducted on the topic. Student-athletes in the Arizona State University- Men's and Women's Track & Field program, specifically those who compete in distance events, were given self reporting surveys to provide injury history and had their foot strike patterns analyzed through video recordings. The survey and analysis of foot strike patterns resulted in data that mostly followed the hypothesized pattern of mid-foot and forefoot striking runners displaying a lower average frequency of injury in comparison to rear foot strikers. The differences in these averages across all injury categories was found to be statistically significant. One category that displayed the most supportive results was in the average frequency of mild injury. This lead to the proposed idea that while foot strike patterns may not be the best predictor of moderate and severe injuries, they may play a greater role in the origin of mild injury. Such injuries can be the gateway to more serious injury (moderate and severe) that are more likely to have their cause in other sources such as genetics or body composition for example. This study did support the idea that foot strike pattern can be the main predictor in incidence of running injuries, but also displayed that it is one of many major factors that contribute to injuries in runners.

Most athletic or daily activities require the use of force production at a given velocity, in other words, power is needed to complete these activities. There are different methods for how this can be done, but the main two are heavy resistance training and plyometric training (Kawamori and Haff, 2004). However, resistance bands are another option of training that is available at a low cost and equipment needs. Resistance bands can also be used by athletes and elderly alike, but so far the benefits have barely been studied. Two participants were recruited to be followed as a case study. Both were of college age and were currently recreationally active with no health or musculoskeletal problems. Both participants were given a 35 lb. resistance band and instructed to do four different lower extremity exercises (three sets of four repetitions each) that were designed to target the muscles used for jumping. The study ran for five weeks, requiring three workouts per week separated by at least 24 hours. Participants were tested at three points; initial, halfway, and after all 15 workouts had been completed. Tests included measuring for changes in maximal vertical jump height as well as maximal broad jump. Results showed that both participants were able to increase their vertical jump and broad jump measurements from the initial testing day. Participant one had a 22.95% and 39.40% increase in broad jump and vertical jump respectively. Participant two had a 7.84% and 11.72% increase in broad jump and vertical jump respectively. Based on this study, it would appear that the power training program is effective in producing an increase in power based off the measured performance variables. There may be some effect from familiarity with testing protocol but most likely increased were caused by neural adaptation from speed aspect of program, as well as some increase in force production.

Medial compartment knee osteoarthritis (OA) is a disease whose severity has been associated with the peak adduction moment during walking (pKAM). Unfortunately, measuring patients' pKAM to track their therapy progress involves the use of a gait laboratory which is expensive and time intensive. This study aimed to develop and assess a regression method to predict the pKAM using only plantar pressure measurements. This approach could greatly reduce the burden of evaluating pKAM.

Workplace injuries, especially those caused by overexertion, are a significant issue among firefighters. This investigation filmed 8 firefighters during simulated firefighting tasks. A detailed movement analysis for each task was completed and used to infer the prime muscles and injury-prone joints during each task. A comprehensive strength training program was developed from this information to help reduce workplace injuries in firefighters.

Ruptures in the anterior cruciate ligament are a prevalent injury, particularly in young athletes. This injury is frequently treated with surgical repair utilizing autologous tissue, cadaver allografts or synthetic grafts. However there is no definitive answer on which is the best graft option. This review aims to compare clinical results of patellar tendon autograft (PT), hamstring autograft (HT), cadaver allograft and LARS synthetic ligament in ACL reconstruction. The ASU library was systematically searched for comparison studies or meta-analyses that compared or described ACL reconstruction graft options. The results of the studies were analyzed according to re-tear rate, return to pre-injury level of activity, KT-1000 laxity scores, post-operative muscle strength, International Knee Documentation Committee Score (IKDC), Lysholm score, Lachman test and donor site morbidity. Allografts showed the highest re-tear rate and increase in laxity when compared with the PT autograft and HT autograft. PT autograft provided the most stability according to the KT-1000 results. Knee extensor muscle strength was not graft dependent, but knee flexor strength decreased significantly in HT autograft patients. All grafts showed comparable results for IKDC, Lysholm scores and Lachman tests. There was increased anterior knee pain in PT autograft patients however this did not seem to have an affect on the stability or durability of the graft. The PT autograft is the best choice for individuals undergoing ACL reconstruction on the basis of lower re-tear rates and greater joint stability.