Research in Biomechanics at KSU by Larry Noble, Specializing in Biomechanics of Exercise and Sport •Courses I teach •Laboratory capabilities •Examples of master’s theses done in our biomechanics lab •Brief review of recent study on bat design •Ongoing research in our biomechanics lab Kansas State University Biomechanics Lab Courses I Teach PKIN 330 Biomechanics PKIN 630 Design and Analysis of Exercise and Sport Equipment PKIN 718 Videographic and Cinematographic Analysis of Human Motion PKIN 825 Mechanical Analysis of Human Movement Kansas State University Biomechanics Lab Kin 825 Course Topics • • • • • • • • • • • • • • • • • • Definition and scope of biomechanics Kinetics review Anthropometry, Total Body COM Observing and Analyzing Human movement Gait Analysis Methods and tools for biomechanical analysis Force Platform Demo Biomechanics of sport Biomechanics of exercise Injury Prevention Electromyography EMG demonstration lab Biomechanics of bone Ergonomics Aging Journal article presentations Journal article & term paper presentations Term paper presentations Kansas State University Biomechanics Lab Biomechanics Laboratory Capabilities PCinematographic equipment (up to 500 fps) Cameras, tripods, lights, marking supplies Analysis equipment and software PVideographic equipment Digital video cameras (up to 240 fps) SVHS cameras, VCRs, lights, marking supplies Equipment and software for 3D analysis PElectromyography equipment APAS 4-channel unit with preamplifies PLoad measurement equipment AMTI force platform, load cells, load beams, accelerometers Kansas State University Biomechanics Lab Examples of Theses From Our Lab PSpragg, Carolyn A. (1986) A comparison of selected mechanical factors in male baseball and female fast pitch softball batting. PHarris, Chad. (1987) Kinematic analysis of the tying phase of calf roping. PYu, Bing. (1988) Determination of the appropriate cutoff frequency in the digital filter data smoothing procedure. PRinger, Geoffrey W. (1992) The effects of exterior loading on selected mechanical and vibrational characteristics of tennis rackets. PPonte, J.M. (1993) A comparison of load characteristics associated with pogo stick bounding and jumping rope. PAllen, G. Christy L. (1994) The effect of preventative drills on stability of the knee in female basketball players. PRoberts, Richard. (1996) The Effects of Hip Flexion on Lumbar Hyperextension and Iemg of Hip Flexors During the Bench Press. PHarper, Denise. (1997) Ground Reaction Force Patterns at Different Velocities using Running Shoes and Combat Boots Kansas State University Biomechanics Lab Theses (cont=d) •Dudley, Chris. A mechanical analysis of the running step technique in volleyball. (1998) •Mendoza, Jennifer. The back handspring on the balance beam: a kinematic comparison of two techniques.(1998) •Benson, Tim. The effect of mound height on pitching kinematics.(1999) •Stroede, Claire. The effect of tennis racket string vibration dampers on racket handle vibrations and discomfort following impacts. (1999) •Hildenbrand, Kasee. Abdominal muscle activity while performing trunk flexion exercises using the Abroller, Abslide, Fit-ball, and conventionally performed trunk curls. (2001) •Harms, Nolan. The Relative Effects of Warmup using Bats of Varying Weights on Bat Velocity and Segmental Movements. (2003) Kansas State University Biomechanics Lab Focus of recent bat research – to evaluate efficacy of new bat design features • Aluminum bats first appeared around 1970 • Since 1980 materials with higher strength/mass ratios have emerged • The plethora of recent innovations are causing concern by softball & baseball governing bodies & are confusing consumers • How do we evaluate these innovations (or gimmicks)? Kansas State University Biomechanics Lab Bat Flexibility Field Test • First, a controlled blind field test involving 6 different bat flexibilities with 32 elite softball players was funded by a bat manufacturer • Results indicated that these hyper-flexible bats resulted in greater post-impact velocity and were preferred by elite slow-pitch hitters over stiffer bats (Noble, Tech Rep to Easton Aluminum 1998) • An examination of bat bending characteristics during the swing followed this study (Noble, Proc ISBS 2001) Kansas State University Biomechanics Lab Does the “springboard”effect, or diving board mode, exist? Kansas State University Is it possible for hitters to take advantage of it? Biomechanics Lab Procedures Kansas State University Biomechanics Lab Procedures Kansas State University Biomechanics Lab Results - Waveform Characteristics in Horizontal Direction Kansas State University Biomechanics Lab Bat Vibrations During Swing & Impact 4 Peak 41 ms PC Begin Swing 233ms PC 3 Horiz Pk 38 ms PC Strain (v) 2 1 0 0 0.1 0.2 0.3 0.4 0.5 0.6 -1 -2 -3 -4 Time (s) Kansas State University Horiz Dir Vert Dir Magnitude Horiz Dir Vert Dir Magnitude Biomechanics Lab 0.7 Kansas State University Biomechanics Lab Begin swing 183 ms PC Peak bending and peak torque ~ 50 ms PC Impact – bat still bent back approx 20% of max Kansas State University Biomechanics Lab Bat Vibrations During Swing and Impact: Conclusions • During the swing, the bat bends back and stores elastic energy that is released during impact • Thus, a more flexible bat would appear to be more effective if the ball impacts at the sweet spot • During impact, the bat behaves as a free-free body • A stiffer bat would appear to be more effective if the ball does not impact at the sweet spot. • Perhaps a stiff bat is better for baseball and fast-pitch softball and a flexible bat is better for slow-pitch softball Kansas State University Biomechanics Lab Ongoing Research • Brett Linbgo – working on prooposal to examine resistive exercise methods using videography and electromyography • Brian Gehlen – working on proposal to examine squat technique • Lab – proposal to evaluate the performance properties and perceptions of use of laminated wood flooring. Kansas State University Biomechanics Lab Questions? Kansas State University Biomechanics Lab