Dowse, RA, Secomb, JL, Bruton, M, Parsonage, J, Ferrier, B, Waddington, G, and Nimphius, S. Ankle proprioception in male and female surfers and the implications of motor experience and lower-body ...strength. J Strength Cond Res 36(12): 3497-3504, 2022-The primary objectives were to evaluate if the active movement extent discrimination apparatus (AMEDA) condition (i.e., front foot and back foot plantarflexion, dorsiflexion, inversion, and eversion) and the level of competition explained ankle movement discrimination scores and, thereafter, examined the contribution of surf experience, physical capacity, and ability to proprioception. It was also considered important to re-evaluate the surf experience, anthropometric characteristics, physical capacities, and abilities of male and female surfers. Twenty-six male ( n = 12, surf experience = 18 ± 8 years) and female surfers ( n = 14, surf experience = 9 ± 6 years) completed a pre-exercise medical questionnaire, anthropometric assessment, 8 AMEDA assessments, countermovement jump, squat jump, and isometric midthigh pull assessment. The AMEDA condition and level of competition did not have a statistically significant main effect on ankle movement discrimination scores; however, the effect of the gender/sex was significant ( p = 0.044). Surf experience ( p = 0.029) and lower-body isometric strength ( p = 0.029) had a statistically significant but small main effect on ankle movement discrimination scores. The results also confirmed that there were significant differences in surf experience, anthropometric characteristics, physical capacity, and jumping ability between male and female surfers. As surf experience and physical capacity were only able to explain a small magnitude of ankle movement discrimination scores, it is suggested that ankle proprioception in surfers may be related to both the volume and quality of the motor experience attained, which may be augmented by environmental and sociocultural factors.
Nimphius, S, McGuigan, MR, and Newton, RU. Relationship between strength, power, speed and change of direction performance of female softball players. J Strength Cond Res 24(4)885-895, 2010-The ...purpose of this study was to investigate (a) the cross-sectional relationship of strength, power, and performance variables in trained female athletes and (b) determine if the relationship between these variables changes over the course of a season. Ten female softball players (age = 18.1 ± 1.6 years, height = 166.5 ± 8.9 cm, and weight = 72.4 ± 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower body strength (one repetition maximum 1RM), peak force (PF), peak velocity (PV), and peak power (PP) during jump squats unloaded and loaded, unloaded countermovement vertical jump height (VJH) 1 base and 2 base sprint performance and change of direction performance on dominant and nondominant sides. The testing sessions occurred pre, mid, and post a 20-week training period. Relationship between body weight (BW), relative strength (1RM/BW), VJH, relative PP, relative PF, PV, speed, and change of direction variables were assessed by Pearson product-moment correlation coefficient at each testing session. Significant relationships were found across all time points with BW, speed, and change of direction measures (r = 0.70-0.93) and relative strength and measures of speed and change of direction ability (r = −0.73−0.85). There were no significant relationships between VJH and any measure of performance at any time point. In conclusion, BW and relative strength have strong to very strong correlations with speed and change of direction ability, and these correlations remain consistent over the course of the season. However, it seems as if many relationships vary with time, and their relationships should therefore be investigated longitudinally to better determine if these cross-sectional relationships truly reflect a deterministic relationship.
In reflection on the numerous studies investigating differences in athletic performance and risk of injury in male and female athletes, I question whether a lack of control or consideration of ...physical capacity (eg, strength) or skill (eg, sport-specific or movement skill) potentially confounds much of this research. As a result, one or more variables that are modifiable through training (eg, strength, sporting, and movement skill) likely explain conclusions attributed to gender/sex.I Therefore, we should critically reevaluate the assumptions that are often made in the research design of gender-comparison studies to increase the underlying validity and avoid generalizations. In the exercise and sport sciences, such design improvements would include providing descriptive measures of participants to ensure that we do not perpetuate an ambiguous and potentially harmful conclusion that is overattributed to inherent gender differences. In the applied environment, removing this type of myopic lens is not only advantageous but necessary in our pursuit of improving performance and reducing injury risk. As experienced practitioners would attest, knowing the gender of the athlete provides much less information than knowing his or her training status (eg, no resistance training) or motor skills (eg, competent running mechanics). Then, why do we allow many studies to conclude something to the effect of “therefore females have different landing mechanics”? These conclusions fail to provide actual physiological or neuromechanical justification capable of broadening our understanding or extending our clinical practice, which should be the purpose of our applied scientific discipline. Furthermore, interpretations of results often fail to acknowledge the large magnitude of overlap in this dichotomous comparison that should have a more multifactorial conclusion than is currently acknowledged.2 Many researchers are seeking to ask more insightful questions to better understand female athletes and, in reality, all athletes. For example, investigators have questioned the underpinning reasons for purported gender-related differences: in sidestepping by highlighting the questionable clinical relevance of reported biomechanical differences,3 in neuromuscular research by using a strength-matched gender study design to question previously reported differences in hamstrings and quadriceps activity between the genders,4 and through critical review of gender in landing research, highlighting that differences between men and women are diminished, if not entirely removed, when skill increases.5 If the previously mentioned critiques are correct, the conclusions and subsequent messaging of potentially oversimplified gender comparisons may contribute to a persistent belief that female athletes are incapable or simply destined to injury or lower performance. Ironically, the perpetuation of such a message may lower belief in these athletes, a factor that has been shown to reduce the ability to learn and control motor skills in children6 and adults.7 Well-designed studies that seek to understand the influence of gender on athletic performance need to consider a multidisciplinary approach to describing or matching male and female participant groups by including basic physiological measures of strength and better descriptions of sporting age or skill (eg, years at highest competition level or sport-specific skill) and athletic training age or skill (eg, years of resistance training or measure of movement skill). This is a much stronger approach to elucidating whether observed differences are a function of a modifiable trait versus that attributable to gender. Our research continues to suggest and use language which assumes that modifiable variables are inherent to female athletes. Instead, the research should be highlighting the modifiable variables of lower strength and motor and sporting skill; not doing so indicates a sporting system (and society) that has failed to provide equal funding, opportunity, and qualified personnel. Despite our best efforts, removal of the stereotypes that threaten the motor skill development of our female athletes remains a problem. Furthermore, the assumption that coaching is the only influence on the attainment of motor skill is naïve and fails to recognize the development of motor skill before becoming “an athlete” and the daily influence society has on our athletes (from a very young age), independent of the training environment that may influence motor learning. Consequently, correct conclusions and messaging from the research that inform the messaging adopted by society are crucial. Lower motor skill attainment not only affects sport-specific skill but may subsequently reduce the transfer of improved strength to a skillful movement. Although strength and neuromuscular adaptations to resistance training are broadly similar in men and women,8 it could be hypothesized that if belief is not present the subsequent ability to learn to use this strength for a transfer to performance9 may not occur as readily in female athletes. Our approach to participant recruitment in many gender-difference studies has created a scenario where we attribute a vast amount of explained variance to binary categorization of male and female by assuming that random or convenience sampling is satisfactory despite the fact that is unlikely such an approach would provide participants with comparable normalized strength, years of movement, or sporting-skill training. As such, undoubtedly well-intended research on female athletes, through lack of control or description of modifiable factors such as strength, skill, and training age, has mostly perpetuated conclusions that overly prescribe the idea of female athletes’ having an inherent “issue.” It is a broad brush that does a disservice to not only our science but also the athletes we seek to support. Our conclusions and use of language are powerful and need to be considered in the design and interpretation of our research studies of female athletes. Note I. Research in exercise and sport science uses the terms gender and sex. For this editorial, the term gender was used in alignment with the International Olympic Committee concerning gender identification and sport participation. Future research should consider the suggested term gender/sex, because gender and sex have been considered nearly inseparable in neuropsychology and therefore it is difficult to purely assess biological sex differences that have implications for motor behavior. References * 1. Kaiser A. Re-conceptualizing “sex” and “gender” in the human brain. Z Psychol. 2012;220(2):130136. KaiserA.Re-conceptualizing “sex” and “gender” in the human brain.Z Psychol.2012;220(2):130136.)| false * Search Google Scholar * Export Citation * 2.↑ Nimphius S. Re-evaluating what we “know” about female athletes in biomechanics research: across the continuum from capacity to skill. ISBS Proc Arch. 2018;36(1):1059. NimphiusS.Re-evaluating what we “know” about female athletes in biomechanics research: across the continuum from capacity to skill.ISBS Proc Arch.2018;36(1):1059.)| false * Search Google Scholar * Export Citation * 3.↑ Benjaminse A, Gokeler A, Fleisig GS, Sell TC, Otten B. What is the true evidence for gender-related differences during plant and cut maneuvers? A systematic review. Knee Surg Sports Traumatol Arthrosc. 2011;19(1):42–54. doi:10.1007/s00167-010-1233-y * Crossref * PubMed BenjaminseA,GokelerA,FleisigGS,SellTC,OttenB.What is the true evidence for gender-related differences during plant and cut maneuvers? A systematic review.Knee Surg Sports Traumatol Arthrosc.2011;19(1):42–54. doi:10.1007/s00167-010-1233-y10.1007/s00167-010-1233-y20734027)| false * Search Google Scholar * Export Citation * 4.↑ Nimphius S, McBride JM, Rice PE, Goodman-Capps CL, Capps CR. Comparison of quadriceps and hamstring muscle activity during an isometric squat between strength-matched men and women. J Sci Med Sport. 2019;18(1):101–108. PubMed ID: 30787657 NimphiusS,McBrideJM,RicePE,Goodman-CappsCL,CappsCR.Comparison of quadriceps and hamstring muscle activity during an isometric squat between strength-matched men and women.J Sci Med Sport.2019;18(1):101–108. PubMed ID: 30787657)| false * Search Google Scholar * Export Citation * 5.↑ Bruton MR, O’Dwyer N, Adams R. Sex differences in the kinematics and neuromuscular control of landing: biological, environmental and sociocultural factors. J Electromyogr Kinesiol. 2013;23(4):747–758. PubMed ID: 23731700 doi:10.1016/j.jelekin.2013.04.012 * Crossref * PubMed BrutonMR,O’DwyerN,AdamsR.Sex differences in the kinematics and neuromuscular control of landing: biological, environmental and sociocultural factors.J Electromyogr Kinesiol.2013;23(4):747–758. PubMed ID: 23731700 doi:10.1016/j.jelekin.2013.04.0122373170010.1016/j.jelekin.2013.04.012)| false * Search Google Scholar * Export Citation * 6.↑ Drews R, Chiviacowsky S, Wulf G. Children’s motor skill learning is influenced by their conceptions of ability. J Mot Learn Devel. 2013;1(2):38–44. doi:10.1123/jmld.1.2.38 * Crossref DrewsR,ChiviacowskyS,WulfG.Children’s motor skill learning is influenced by their conceptions of ability.J Mot Learn Devel.2013;1(2):38–44. doi:10.1123/jmld.1.2.3810.1123/jmld.1.2.38)| false * Search Google Scholar * Export Citation * 7.↑ Wulf G, Lewthwaite R. Conceptions of ability affect motor learning. J Mot Behav. 2009;41(5):461–467. PubMed ID: 19491058 doi:10.3200/35-08-083 * Crossref * PubMed WulfG,LewthwaiteR.Conceptions of ability affect motor learning.J Mot Behav.2009;41(5):461–467. PubMed ID: 19491058 doi:10.3200/35-08-08310.3200/35-08-08319491058)| false * Search Google Scholar * Export Citation * 8.↑ Staron RS, Karapondo DL, Kraemer WJ, et al. Skeletal muscle adaptations during early phase of heavy-resistance training in men and women. J Appl Physiol. 1994;76(3):1247–1255. PubMed ID: 8005869 doi:10.1152/jappl.1994.76.3.1247 * Cross
To assess whether a battery of performance markers, both individually and as group, would be sensitive to fatigue, a within group random cross-over design compared multiple variables during seated ...control and fatigue (repeated sprint cycling) conditions. Thirty-two physically active participants completed a neuromuscular fatigue questionnaire, Stroop task, postural sway, squat jump, countermovement jump, isometric mid-thigh pull and 10 s maximal sprint cycle (Sprintmax) before and after each condition (15 min, 1 h, 24 h and 48 h). In comparison to control, larger neuromuscular fatigue questionnaire total score decrements were observed 15 min (5.20 ± 4.6), 1 h (3.33 ± 3.9) and 24 h (1.83 ± 4.8) after cycling. Similarly, the fatigue condition elicited greater declines than control at 15 min and 1 h post in countermovement jump height (1.67 ± 1.90 cm and 1.04 ± 2.10 cm), flight time-contraction time ratio (0.03 ± 0.06 and 0.05 ± 0.11), and velocity (0.06 ± 0.07 m∙s-1 and 0.04 ± 0.08 m∙s-1). After fatigue, decrements were observed up to 48 h for average Sprintmax cadence (4-6 RPM), up to 24 h in peak Sprintmax cadence (2-5 RPM) and up to 1 h in average and peak Sprintmax power (45 ± 60 W and 58 ± 71 W). Modelling variables in a stepwise regression demonstrated that CMJ height explained 53.2% and 51.7% of 24 h and 48 h Sprintmax average power output. Based upon these data, the fatigue induced by repeated sprint cycling coincided with changes in the perception of fatigue and markers of performance during countermovement and squat jumps. Furthermore, multiple regression modelling revealed that a single variable (countermovement jump height) explained average power output.
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ABSTRACTde Hoyo, M, Núñez, FJ, Sañudo, B, Gonzalo-Skok, O, Muñoz-López, A, Romero-Boza, S, Otero-Esquina, C, Sánchez, H, and Nimphius, S. Predicting loading intensity measuring velocity in barbell ...hip thrust exercise. J Strength Cond Res XX(X)000–000, 2019—The barbell hip thrust is an increasingly used exercise to target the hip extensors. Direct and indirect measurement of 1 repetition maximum (1RM) to determine the relative load of each exercise is time-consuming; therefore, practitioners may be more in favor of monitoring velocity and determining relative load through velocity-based prediction models for an exercise. This study aimed to assess the relationship between mean velocity (MV) and mean propulsive velocity (MPV) at different relative training loads (%1RM) in the barbell hip thrust exercise. One hundred two male sport science students performed an incremental 1RM testing protocol for the barbell hip thrust exercise, and a linear position transducer measured MV and MPV of the barbell. The 1RM was reached at 0.25 ± 0.03 m·s, and the regression model generated to estimate a relative load showed an acceptable standard error of estimate (7.01 ± 1.05% 1RM and 7.36 ± 1.05% 1RM for MV and MPV, respectively) with a very large explained variance (R = 0.94). These results may have important practical applications for the prescription and monitoring of the accessory exercise of the hip thrust for monitoring training load and predicting 1RM without undertaking a RM test.
Understanding the magnitude of forces and lower body kinematics that occur during a change of direction (COD) task can provide information about the biomechanical demands required to improve ...performance. To compare the magnitude of force, impulse, lower body kinematics and post-COD stride velocity produced between athletes of different strength levels during a COD task, 12 stronger (8 males, 4 females) and 12 weaker (4 males, 8 females) recreational team sport athletes were recruited. Strength levels were determined by relative peak isometric force of the dominant and non-dominant leg. All athletes performed 10 pre-planned 45° changes of direction (5 left, 5 right) while three-dimensional motion and ground reaction force (GRF) data were collected. Differences in all variables for the dominant leg were examined using a one-way analysis of variance (ANOVA) with a level of significance set at p ≤0.05. The stronger group displayed significantly faster post-COD stride velocity and greater vertical and horizontal braking forces, vertical propulsive force, vertical braking impulse, horizontal propulsive impulse, angle of peak braking force application, hip abduction and knee flexion angle compared to the weaker group. The results suggest that individuals with greater relative lower body strength produced higher magnitude plant foot kinetics and modified lower body positioning while producing faster COD performances. Future investigations should determine if strength training to enable athletes to increase plant foot kinetics while maintaining or adopting a lower body position results in a concomitant increases in post-COD stride velocity.
Sidesteps can impose high demands on the knee joint and lead to non-contact anterior cruciate ligament (ACL) injuries. Understanding how different constraints shape an athlete’s movement strategy and ...the associated joint demands can help design training interventions to increase injury resilience. Motor capacities, such as muscular strength and power, act as boundaries for the safe execution of perceptual–motor skills and co-determine the emergence of unique movement strategies. Increasing single- and multi-joint strength enables a broader solution space for movement strategies and increases load tolerance. Manipulating task constraints during sidesteps can be used in the training process to systematically expose athletes to increasing demands (on the knee joint or any joint or structure) in preparation for “worst-case” scenarios. In particular, the type and timing of information available influence the preparation time, subsequently affecting the movement strategy and the associated magnitude of external knee joint loading (e.g., knee valgus moment). While an athlete’s perceptual–cognitive skills contribute to the preparation time during in situ scenarios, attempts to further improve those skills with the aim of increasing athlete preparation time prior to “worst-case” scenarios are yet to demonstrate conclusive evidence of transfer to on-field situations. Therefore, in the current article, we reflect on the impact of different interacting constraints that influence the execution of sidesteps during in situ scenarios and impose high demands on the knee joint. Subsequently, we discuss how an integrated perspective, drawing on knowledge and perspectives from strength and conditioning and perception–action, may enhance an athlete’s ability to withstand “worst-case” scenarios and adapt to perform varied movement executions when sidestepping.
Anterior cruciate ligament (ACL) injuries have been a rising concern in the early years of the women’s Australian Football League (AFLW), eliciting headlines of a ‘knee crisis’ surrounding the ...league. There has been a focus on female biology as the primary factor driving the high rate of ACL injuries in the AFLW. Emphasising Australian football (AF) as being dangerous predominantly due to female biology may be misrepresenting a root cause of the ACL injury problem, perpetuating gender stereotypes that can restrict physical development and participation of women and girls in the sport. We propose that an approach addressing environmental and sociocultural factors, along with biological determinants, is required to truly challenge the ACL injury problem in the AFLW. Sports science and medicine must therefore strive to understand the whole system of women in AF, and question how to address inequities for the benefit of the athletes.
ABSTRACTLoturco, I, Pereira, LA, Reis, VP, Abad, CCC, Freitas, TT, Azevedo, PHSM and Nimphius, S. Change of direction performance in elite players from different team sports. J Strength Cond Res ...XX(X)000–000, 2020—The primary aim of this study was to examine the differences in change of direction (COD) deficit between elite futsal, soccer, handball, and rugby players. A secondary aim was to compare the performance in both COD and linear speed tests among these athletes. One-hundred sixty-one elite male players from 4 team sports performed a 20-m linear sprint speed and a Zigzag COD speed test. The COD deficit was calculated as the difference between linear and Zigzag test velocities. Differences in COD speed, COD deficit, and sprint velocity were assessed via 1-way analysis of variance. The significance level was set at p < 0.05. Soccer players displayed significantly lower performance than the remaining team sports, and rugby players performed better than all the other groups in the Zigzag COD test. Moreover, the COD deficit was significantly higher in soccer players in comparison with the other disciplines (p < 0.05). No differences were observed in the COD deficit among rugby, futsal, and handball players (p > 0.05). In summary, soccer players were slower than futsal, handball, and rugby players to change direction and presented the greatest COD deficit magnitude. By contrast, the fastest athletes in the COD speed test (rugby players) were not more effective than futsal and handball players at changing direction (as they exhibited similar levels of COD deficit). Coaches should be aware of this evidence, which reinforces previous findings, indicating that very specialized training strategies might be required to improve COD performance in professional athletes.
ABSTRACTNimphius, S, McGuigan, MR, and Newton, RU. Changes in muscle architecture and performance during a competitive season in female softball players. J Strength Cond Res 26(10)2655–2666, 2012—The ...purpose of this research was (a) to examine the performance changes that occur in elite female softball players during 20 weeks of softball training (that included 14 weeks of periodized resistance training RT) and (b) to examine the relationship between percent change (%change) in muscle architecture variables and %change in strength, speed, and change of direction performance. Ten female softball players (age = 18.1 ± 1.6 years, height = 166.5 ± 8.9 cm, weight = 72.4 ± 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower-body strength using a 3 repetition maximum for a predicted 1 repetition maximum (1RM) and peak force, peak velocity (PV), and peak power (PP) were measured during jump squats (JS) unloaded and loaded. In addition, the first base (1B) and the second base (2B) sprint performance, change of direction (505) on dominant (D) and nondominant (ND) sides, aerobic capacity, and muscle architecture characteristics of vastus lateralis (VL) including muscle thickness (MT), fascicle length (FL), and pennation angle (θp) were examined. The testing sessions occurred pre, mid, and post training (total 20 week pre- and in-season training period). Changes over time were analyzed by repeated-measures analysis of variance. The relationship between %change in muscle architecture variables and strength, speed, and change of direction variables from pre to post were assessed by Pearson product-moment correlation coefficient. Significant improvements in PV and PP occurred at all JS loads pre- to mid-testing and pre- to post-testing. Significant increases occurred pre-post in absolute 1RM, relative 1RM, 505 ND, and 2B sprint. The strongest relationships were found between %change in VL MT and 1B sprint (r = −0.80, p = 0.06), %change in VL FL and 2B sprint (r = −0.835, p = 0.02), and %change in relative 1RM and 505 D (r = −0.70, p = 0.04). In conclusion, gains in strength, power, and performance can occur during the season in elite softball players who are also engaged in a periodized RT program. Furthermore, changes in performance measures are associated with changes in muscle architecture.
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