Recent research has revealed that a person or team wearing red is more likely to win a physical contest than a person or team wearing another color. In the present research, we examined whether red influences perceptions of relative dominance and threat in an imagined same-sex competitive context, and did so attending to the distinction between wearing red oneself and viewing red on an opponent. Results revealed a bidirectional effect: wearing red enhanced perceptions of one’s relative dominance and threat, and viewing an opponent in red enhanced perceptions of the opponent’s relative dominance and threat. These effects were observed across sex, and participants seemed unaware of the influence of red on their responses. Our findings lead to practical suggestions regarding the use of colored attire in sport contexts, and add to an emerging, provocative literature indicating that red has a subtle but important influence on psychological functioning.
Roger Feltman and Andrew J. Elliot
Mutlu Cug, Erik A. Wikstrom, Bahman Golshaei and Sadettin Kirazci
Both female athletes’ participation in soccer and associated injuries have greatly increased in recent years. One issue is the 2–9 times greater incidence of noncontact anterior cruciate ligament (ACL) injuries in female athletes relative to male athletes in comparable sports. Several factors such as limb dominance and sporting history have been proposed to play a role in ACL incidence rates between male and female athletes. However, evidence about the effects of these factors and how they interact with sex is mixed, and thus no consensus exists.
To quantify the effects of sports participation, limb dominance, and sex on dynamic postural control and knee-joint proprioception.
University research laboratory.
19 male soccer players, 17 female soccer players, 19 sedentary men, and 18 sedentary women.
Joint-position sense was tested using reproduction of passive positioning on a Biodex isokinetic dynamometer (30°, 45°, and 60° from 90° of knee flexion). Three Star Excursion Balance Test directions were used to assess dynamic postural control.
Main Outcome Measure:
Normalized reach distance (% of leg length) in the anterior, posteromedial, and posterolateral directions on each leg quantified dynamic postural control. Average absolute error and constant error for both limbs quantified joint-position sense.
Posteromedial reach distance was significantly better in soccer players than sedentary individuals (P = .006). Anterior reach distance was significantly better (P = .04) in sedentary individuals than soccer players. No limb-dominance or sex differences were identified for dynamic postural control, and no differences in absolute- or constant-error scores were identified.
Sporting history has a direction-specific impact on dynamic postural control. Sporting history, sex, and limb dominance do not influence knee-joint proprioception when tested in an open kinetic chain using passive repositioning.
Xiaogang Hu and Karl M. Newell
This study investigated the asymmetry of bilateral interference in relation to the relative difference of force amplitude between hands and the hand dominance. In Experiment 1, one hand produced a fixed constant force of 5% maximum voluntary contraction (MVC) while the other hand produced different constant forces of 5%, 20%, and 50% MVC in blocked conditions. Asymmetric interference in force amplitude alone was evident in that the hand producing the fixed low force showed a stronger interference than the hand performing the higher force. Asymmetric interference in hand dominance was also found in that more interference was observed when the nondominant left hand produced the higher force, a finding that does not support the hemisphere specialization hypothesis. Experiment 2 was performed to rule out the fixed force level interpretation compared with the low force level account and the fixed force was set at 50% MVC. The results were consistent with the findings in Experiment 1 showing asymmetric interference with force amplitude rather than with fixed force level. The findings revealed that without a timing constraint the task demand associated with force amplitude alone can induce the asymmetric bilateral interference. The external task asymmetry and intrinsic asymmetry of the organism interact and influence the bimanual force coordination and control patterns.
Alireza Esmaeili, Andrew M. Stewart, William G. Hopkins, George P. Elias and Robert J. Aughey
Detrimental changes in tendon structure increase the risk of tendinopathies. The aim of this study was to investigate the influence of individual internal and external training loads and leg dominance on changes in the Achilles and patellar tendon structure.
The internal structure of the Achilles and patellar tendons of both limbs of 26 elite Australian footballers was assessed using ultrasound tissue characterization at the beginning and the end of an 18-wk preseason. Linear-regression analysis was used to estimate the effects of training load on changes in the proportion of aligned and intact tendon bundles for each side. Standardization and magnitude-based inferences were used to interpret the findings.
Possibly to very likely small increases in the proportion of aligned and intact tendon bundles occurred in the dominant Achilles (initial value 81.1%; change, ±90% confidence limits 1.6%, ±1.0%), nondominant Achilles (80.8%; 0.9%, ±1.0%), dominant patellar (75.8%; 1.5%, ±1.5%), and nondominant patellar (76.8%; 2.7%, ±1.4%) tendons. Measures of training load had inconsistent effects on changes in tendon structure; eg, there were possibly to likely small positive effects on the structure of the nondominant Achilles tendon, likely small negative effects on the dominant Achilles tendon, and predominantly no clear effects on the patellar tendons.
The small and inconsistent effects of training load are indicative of the role of recovery between tendon-overloading (training) sessions and the multivariate nature of the tendon response to load, with leg dominance a possible influencing factor.
Viswanath B. Unnithan and Bogdan Wilk
The aim of this study was to examine the effect of upper-limb dominance on the forearm sweating pattern in cerebral palsy (CP). Eight boys with CP (13.1 ± 3.1 years) performed three 10-min bouts of an arm-cranking exercise at 35°C, 50% relative humidity. After the third bout, the sweat drops on both forearms were photographed. Sweat gland density (PD) and the average sweat drop area (DA) were determined. PD was significantly higher (p < .05), whereas DA was significantly lower (p < .05) on the nondominant compared with the dominant forearm. The sweating pattern in spastic CP is influenced by upper-limb dominance.
Yun Wang and Kazuhiko Watanabe
The notion of limb dominance has been commonly used in the upper extremity, yet the two lower extremities are often treated as equal for analytical purposes. Attempts to determine the effects of limb laterality on gait have produced conflicting results. The purpose of this study was to determine if limb dominance affects the vertical ground reaction force and center of pressure (COP) during able-bodied gait. The Parotec system (Paromed GmbH, Germany) was used to collect plantar foot pressure data. Fifteen subjects volunteered to participate in this study. The coefficient of variation of the COP displacement in the mediolateral direction and the variability of peak force beneath the lateral forefoot in the nondominant foot were significant greater than in the dominant foot. Moreover, COP velocity in the anterior-posterior direction during the terminal stance phase showed greater value in the dominant foot. Our study provides support for limb laterality by showing limb dominance affected the vertical ground reaction force and center of pressure during walking gait. This finding suggests it is an important issue in movement science for clinicians and would assist in improving sports performance and rehabilitation program.
John E. Kovaleski, Robert J. Heitman, Larry R. Gurchiek, Joel W. Erdmann and Terry L. Trundle
The purpose of this study was to assess the reliability of the Closed Chain Rider System (Mettler Electronics) between exercise sessions and to determine the effects of limb dominance using muscle force and work measures during closed chain leg press exercise. Thirty-nine recreationally active college students underwent identical testing on two occasions, during which each subject performed five reciprocal leg press movements at speeds of 10, 15, and 20 in./s while seated. Average force, total work, and linear range of motion were recorded. Reliability values for average force and work were clinically acceptable for the dominant and nondominant limbs. The dominant limb produced greater average force and total work versus the nondominant limb, and average linear ROM was similar between the dominant and nondominant limbs. Differences in the torque and work values observed suggest that the clinician must be aware of differences between the dominant and nondominant limbs when used for comparative purposes.
Jonathon S. Schofield, Eric Parent, Justin Lewicke, Jason P. Carey, Marwan El-Rich and Samer Adeeb
Sit-to-stand transfer is a common prerequisite for many daily tasks. Literature often assumes symmetric behavior across the left and right side. Although this assumption of bilateral symmetry is prominent, few studies have validated this supposition. This pilot study uniquely quantifies peak joint moments and ground reaction forces (GRFs), using a Euclidian norm approach, to evaluate bilateral symmetry and its relation to lower limb motor-dominance during sit to stand in ten healthy males. Peak joint moments and GRFs were determined using a motion capture system and inverse dynamics. This analysis included joint moment contributions from all three body planes (sagittal, coronal, and axial) as well as vertical and shearing GRFs. A paired, one-tailed t test was used, suggesting asymmetrical joint moment development in all three lower extremity joints as well as GRFs (P < .05). Furthermore, using an unpaired two-tailed t test, asymmetry developed during these movements does not appear to be predictable by participants’ lower limb motor-dominance (P < .025). Consequently, when evaluating sit-to-stand it is suggested the effects of asymmetry be considered in the interpretation of data. The absence of a relationship between dominance and asymmetry prevents the suggestion that one side can be tested to infer behavior of the contralateral.
Rodrigo R. Bini and Patria A. Hume
The accuracy of commercial instrumented crank systems for symmetry assessment in cycling has not been fully explored. Therefore, the authors’ aims were to compare peak crank torque between a commercial instrumented crank system and instrumented pedals and to assess the effect of power output on bilateral asymmetries during cycling. Ten competitive cyclists performed an incremental cycling test to exhaustion. Forces and pedal angles were recorded using right and left instrumented pedals synchronized with crank-torque measurements using an instrumented crank system. Differences in right (dominant) and left (nondominant) peak torque and asymmetry index were assessed using effect sizes. In the 100- to 250-W power-output range, the instrumented pedal system recorded larger peak torque (dominant 55–122%, nondominant 23–99%) than the instrumented crank system. There was an increase in differences between dominant and nondominant crank torque as power output increased using the instrumented crank system (7% to 33%) and the instrumented pedals (9% to 66%). Lower-limb asymmetries in peak torque increased at higher power-output levels in favor of the dominant leg. Limitations in design of the instrumented crank system may preclude the use of this system to assess peak crank-torque symmetry.
Scott Ross, Kevin Guskiewicz, William Prentice, Robert Schneider and Bing Yu
T o determine differences between contralateral limbs’ strength, proprio-ception, and kinetic and knee-kinematic variables during single-limb landing.
Hip, knee, and foot isokinetic peak torques; anterior/posterior (AP) and medial/lateral (ML) sway displacements during a balance task; and stabilization times, vertical ground-reaction force (VGRF), time to peak VGRF, and knee-flexion range of motion (ROM) from initial foot contact to peak VGRF during single-limb landing.
The kicking limb had significantly greater values for knee-extension (P = .008) and -flexion (P = .047) peak torques, AP sway displacement (P = .010), knee-flexion ROM from initial foot contact to peak VGRF (P < .001), and time to peak VGRF (P = .004). No other dependent measures were significantly different between limbs (P > .05).
The kicking limb had superior thigh strength, better proprioception, and greater knee-flexion ROM than the stance limb.