Vol 3, No 4 (2015) by Scott Lynn
Punching is integral to success in combat sports, making it a frequent activity during practice/t... more Punching is integral to success in combat sports, making it a frequent activity during practice/training. Improving safety of this activity benefits both the athlete and training partners. This study was designed to 1) test the precision and reliability of a commercially available striking device and 2) assess the influence of a novel padded hand wrap on punching force in elite and untrained punchers. Fourteen male professional boxers and mixed martial artists (PRO; age=29.2±5.6y; height=180.3±9.0cm; mass=87.1±17.9kg, winning %=73.8±13.8%, number of victories via knockout/technical knockout=35.6± 21.9%) and 24 untrained male punchers (UNT; 27.6±6.9y, 177.6±18.3cm, 84.3±16.9kg) wore a standardized boxing glove and performed 20 maximal punches (4 sets of 5) into a device designed to measure punching force. All participants performed, in a counterbalanced order, 2 sets of 5 with a standardized hand wrap and 2 sets of 5 with the same wrap plus an additional 1.2cm thick cylinder 4g foam-like pad (WRAP) placed over the knuckles. PRO produced significantly more punching force than UNT, regardless of condition. Punching force was lower by 12.6% (p<0.05) for PRO and 8.9% (p<0.05) for UNT with WRAP (compared to no WRAP). These findings suggest WRAP significantly reduces punching force, which may be important for long-term safety of the puncher’s hand and/or the person receiving the strike
Papers by Scott Lynn
Journal of Strength and Conditioning Research, Mar 1, 2011
Medicine and Science in Sports and Exercise, May 1, 2011
characteristics were age 21.73 +0.56 yrs, height 171.98 +2.36 cm, body mass 78.34 +5.63 kg. Data ... more characteristics were age 21.73 +0.56 yrs, height 171.98 +2.36 cm, body mass 78.34 +5.63 kg. Data were analyzed using a repeated measures analysis of variance (ANOVA) with an alpha level of 0.05. When significance was found, paired sample t-tests determined pair-wise differences using a Bonferroni corrected alpha level of 0.01. RESULTS: TUT was lower with BFR (p=0.001) following the first [BFR 41.20 +2.42 vs CON 55.73 +3.18 s] and second set [BFR 8.53 +0.86 vs CON 22.66 +1.09 s]. WBL was higher post exercise in CON when compared to OCC (p=0.002) [BFR 1.76 +0.74 vs CON 3.09+1.17 mmol/l], but not different at other time points. HR between groups were similar throughout [BFR 91.16 +3.60 vs CON 93.00 +2.86 bpm]. CONCLUSIONS: KW provide a BFR stimulus allowing failure to occur with less TUT during low intensity leg extensor training. WBL increased following failure in CON over BFR, but reperfusion resulted in a greater efflux of La following BFR, resulting in no differences 3 to 10 minutes post-exercise. HR was not different among groups at any time point. KW may benefit populations who cannot sustain the mechanical stress of high intensity exercise or low intensity exercise which requires a longer sustained TUT.
Medicine and Science in Sports and Exercise, May 1, 2010
The 13th Conference of the International Sports Engineering Association, 2020
Golf is a sport which requires players to use ground interaction to generate clubhead speed in or... more Golf is a sport which requires players to use ground interaction to generate clubhead speed in order to propel the ball towards the target. Force platforms are a technology which can be used to measure these ground reaction forces. Golfers generate force through a combination of jumping, sliding or twisting actions during the swing. Understanding how golfers generate these forces and if there are any groups which golfers could be clustered into could be used to enhance golf instruction as well as clubhead design or fitting practices for golf equipment. A total of 105 right-handed experienced golfers (handicap mean = 8.32 ± 8.31) consented to participate in the study of different swing speeds (31 below 95 mph, 41 over 105 mph and 33 between 95 and 105 mph). A calibrated single force plate was used for the test which sampled at 1000 Hz and recorded force and moment data in three axes. After a self-guided warm up, the players were instructed to hit five 7-iron shots and five drives to ...
Medicine & Science in Sports & Exercise, 2015
Journal of Strength and Conditioning Research, 2011
Unassisted increased jump height subsequently increases descending velocity resulting in increase... more Unassisted increased jump height subsequently increases descending velocity resulting in increased impact forces. Increased impact forces produce greater eccentric forces, which may lead to greater muscular adaptations. This is less well understood during an assisted jump. PURPOSE: The purpose of this study was to investigate the effects of different assisted jumping conditions on relative impact forces (RIF) and descent velocity (DV). METHODS: Thirty recreationally trained subjects (male = 15, female = 15) completed three testing sessions consisting of five experimental conditions: body weight reduction (BWR) of 0%, 10%, 20%, 30%, or 40%. In all conditions, subjects wore a full body harness while attached to two elastic cords, suspended and bolted to the ceiling. Subjects performed three maximal countermovement jumps with arm swing on a force plate with a velocity transducer for each condition. Maximum jump height (JH) values using a vertec for each condition were used for analyses. RESULTS: JH significantly (p , 0.05) increased across conditions (0% = 35.14 6 9.02 cm, 40% = 79.44 6 14.12 cm). Additionally, DV at 30% and 40% were significantly greater than 0%, 10%, and 20%, however, no differences were found between 30% and 40% (0% = 2.57 6
Medicine and science in sports and exercise, Jan 21, 2017
Large imbalances between limbs are common and potentially dangerous, yet few studies have simulta... more Large imbalances between limbs are common and potentially dangerous, yet few studies have simultaneously examined performance and physiological asymmetries. The current study examined the associations between lower limb dominance, drop-jumping kinematics, maximal strength, and myosin heavy chain (MHC) fiber type in the vastus lateralis (VL). Thirteen resistance-trained men (age=24.3±2.7y; height=181.4±6.6cm; mass=87.7±11.3kg) identified their dominant (DOM) and non-dominant (ND) limb, performed drop jumps (30cm) and maximal knee extensions (1RM), and provided biopsies from both VL muscles for single fiber (109±36/limb/person) MHC fiber type identification (FT%). All participants selected "right" as the "preferred kicking limb" (DOM). DOM displayed a trend for a greater eccentric knee angular velocity (EKV) (p=0.083) and a significantly greater concentric KV (CKV) (p=0.002) during drop-jump. DOM also tended to be stronger than ND (64.3±11.3 vs. 61.0±8.8 kg, p=0.06...
Medicine & Science in Sports & Exercise, 2014
Medicine & Science in Sports & Exercise, 2017
Medicine & Science in Sports & Exercise, 2015
Medicine & Science in Sports & Exercise, 2016
We caused myocardial infarction via ligation of the left anterior descending coronary artery to i... more We caused myocardial infarction via ligation of the left anterior descending coronary artery to induce CHF in mice, while sham animals received identical surgical procedures except ligation. We performed experiments 14-16 weeks post-surgery, and tested contractile properties of permeabilized diaphragm single fibers with or without exposure to the thiol-reducing agent dithiothreitol (DTT, 10 mM for 10min) prior to calcium activation. RESULTS: Maximal specific force (sFo) of diaphragm fibers was decreased in CHF compared to sham (in kN•m-2, 132.3 ±6.5 and 96.9 ±6.0), and sFo of fibers from CHF mice was increased by DTT treatment (126.3 ±6.6 kN•m-2). The rate constant of tension redevelopment (Ktr) was slower in CHF diaphragm fibers than sham (in s-1 44.12 ±3.9 and 31.26 ±2.4), and DTT treatment increased Ktr (41.4 ±1.7 s-1). Calcium sensitivity was unchanged by either CHF or DTT treatment. DTT had no effect on the single fiber contractile parameters (sFo, Ktr and pCa50) in sham animals. CONCLUSIONS: Our findings suggest that reversible thiol oxidation of sarcomeric proteins is a molecular mechanism of diaphragm fiber contractile dysfunction in CHF.
Journal of Strength and Conditioning Research, 2016
The purpose of this study was to determine the effects of deadlift chain variable resistance on s... more The purpose of this study was to determine the effects of deadlift chain variable resistance on surface electromyography (EMG) of the gluteus maximus, erector spinae, and vastus lateralis muscles, ground reaction forces (GRFs), and rate of force development (RFD). Thirteen resistance trained men (24.0 ± 2.1 y, 179.3 ± 4.8 cm, 87.0 ± 10.6 kg) volunteered for the study. On day one, subjects performed 1 repetition maximum (1RM) testing of the deadlift exercise. On day two, subjects performed one set of three repetitions with a load of 85% 1RM with (CH) and without chains (NC). The order of the CH and NC conditions was randomly determined for each subject. For the CH condition, the chains accounted for approximately 20% (19.9 ± 0.6%) of the 85% 1RM load, matched at the top of the lift. Surface EMG was recorded to differentiate muscle activity between conditions (CH, NC), range of motion (ROM; bottom, top) and phase (concentric, eccentric). Peak GRFs and RFD were measured using a force plate. EMG results revealed that for the gluteus maximus there was significantly greater EMG activity during the NC condition versus the CH condition. For the erector spinae, EMG activity was greater at the bottom than the top ROM (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Force plate results revealed that deadlifting at 85% 1RM with an accommodating chain resistance of approximately 20% results in a reduction in GRFs (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) and no change in RFD (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05). Collectively, these results suggest that the use of chain resistance during deadlifting can alter muscle activation and force characteristics of the lift.
International Journal of Kinesiology and Sports Science, 2015
Punching is integral to success in combat sports, making it a frequent activity during practice/t... more Punching is integral to success in combat sports, making it a frequent activity during practice/training. Improving safety of this activity benefits both the athlete and training partners. This study was designed to 1) test the precision and reliability of a commercially available striking device and 2) assess the influence of a novel padded hand wrap on punching force in elite and untrained punchers. Fourteen male professional boxers and mixed martial artists (PRO; age=29.2±5.6y; height=180.3±9.0cm; mass=87.1±17.9kg, winning %=73.8±13.8%, number of victories via knockout/technical knockout=35.6± 21.9%) and 24 untrained male punchers (UNT; 27.6±6.9y, 177.6±18.3cm, 84.3±16.9kg) wore a standardized boxing glove and performed 20 maximal punches (4 sets of 5) into a device designed to measure punching force. All participants performed, in a counterbalanced order, 2 sets of 5 with a standardized hand wrap and 2 sets of 5 with the same wrap plus an additional 1.2cm thick cylinder 4g foam-like pad (WRAP) placed over the knuckles. PRO produced significantly more punching force than UNT, regardless of condition. Punching force was lower by 12.6% (p<0.05) for PRO and 8.9% (p<0.05) for UNT with WRAP (compared to no WRAP). These findings suggest WRAP significantly reduces punching force, which may be important for long-term safety of the puncher's hand and/or the person receiving the strike.
Journal of Strength and Conditioning Research, 2015
The bench press is one of the most commonly used upper body exercises in training and is performe... more The bench press is one of the most commonly used upper body exercises in training and is performed with many different variations, including unstable loads. While there is much research on use of an unstable surface, there is little to none on the use of an unstable load (UL). The purpose of this study was to investigate muscle activation during the bench press while using a stable load (SL) vs. UL. Twenty resistance trained men (age = 24.1 ± 2 yrs.; ht = 177.5 ± 5.8 cm; mass = 88.7 ± 13.7 kg) completed 2 experimental conditions (SL and UL) at two different intensities (60% and 80% 1RM). UL was achieved by hanging 16kg kettlebells by elastic bands from the end of the bar. All trial lifts were set to a two second cadence with a slight pause at the bottom. Subjects had electrodes attached to 5 muscles (pectoralis major, anterior deltoid, medial deltoid, triceps brachii and latissimus dorsi) and performed three isometric bench press trials to normalize electromyographic data. All five muscles demonstrated significantly greater activation at 80% compared to 60% load and during concentric compared to eccentric actions. These results suggest that upper body muscle activation is not different in the bench press between UL and SL. Therefore, coaches should use their preference when designing training programs.
Journal of sports science & medicine, 2015
The purpose of this study was to determine the effect of foot strike patterns and converted foot ... more The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.8±2.2 years, mass = 73.1±14.5 kg, height 1.75 ± 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern -forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group - PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on sp...
Journal of sports science & medicine, 2010
Golf has the potential to keep people active well into their later years. Injuries to the target ... more Golf has the potential to keep people active well into their later years. Injuries to the target side knee have been reported in golfers, yet no mechanisms for these injuries have been proposed. The loads on the knee during the golf swing may be insufficient to cause acute injury, yet they may be a factor in the progression of overuse/degenerative conditions; therefore, research developing swing modifications that may alter loading of the knee is warranted. It has been suggested that the proper golf set-up position has the target-side foot externally rotated but no reasoning for this modification has been provided. Frontal plane knee moments have been implicated in many knee pathologies. Therefore, this study used a 3-dimensional link segment model to quantify the frontal plane knee moments during the golf swing in a straight (STR) and externally rotated (EXT) target-side foot position. Subjects were 7 collegiate golfers and knee moments were compared between conditions using repeat...
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Vol 3, No 4 (2015) by Scott Lynn
Papers by Scott Lynn