Postural stability has traditionally been examined through spatial measures of the center of mass (CoM) or center of pressure (CoP), where larger amounts of CoM or CoP movements are considered signs of postural instability. However, for stabilization, the postural control system may utilize additional information about the CoM or CoP such as velocity, acceleration, and the temporal margin to a stability boundary. Postural time-to-contact (TtC) is a variable that can take into account this additional information about the CoM or CoP. Postural TtC is the time it would take the CoM or CoP, given its instantaneous trajectory, to contact a stability boundary. This is essentially the time the system has to reverse any perturbation before stance is threatened. Although this measure shows promise in assessing postural stability, the TtC values derived between studies are highly ambiguous due to major differences in how they are calculated. In this study, various methodologies used to assess postural TtC were compared during quiet stance and induced-sway conditions. The effects of the different methodologies on TtC values will be assessed, and issues regarding the interpretation of TtC data will also be discussed.
Jeffrey M. Haddad, Jeff L. Gagnon, Christopher J. Hasson, Richard E.A. Van Emmerik and Joseph Hamill
Alice D. LaGoy, Caleb Johnson, Katelyn F. Allison, Shawn D. Flanagan, Mita T. Lovalekar, Takashi Nagai and Chris Connaboy
load carriage on the warfighter be understood. 1 , 9 – 12 Additional load reduces the dynamic postural stability of an individual, and compromised dynamic postural stability may contribute to the increased injury risk associated with load carriage. 13 – 15 Dynamic postural stability refers to the
Timothy C. Sell, Mita T. Lovalekar, Takashi Nagai, Michael D. Wirt, John P. Abt and Scott M. Lephart
females for greater risk of injury or may require additional or different training to meet the gender-neutral requirements of the newly opened MOS. 8 , 9 Postural stability is a dynamic process that requires sensory detection of body motions, integration of sensorimotor information within the central
Caroline Westwood, Carolyn Killelea, Mallory Faherty and Timothy Sell
Concussions are a significant problem in athletic populations and can cause several severe symptoms. 1 Studies have shown that athletes who suffer concussions often have persistent postural stability deficits. 1 Long-term effects include an increased risk of lower-extremity injury, 2
Joshua J. Liddy, Amanda J. Arnold, HyeYoung Cho, Nathaniel L. Romine and Jeffrey M. Haddad
object has been proposed as a potential assistive strategy for increasing postural stability in balance-compromised populations. 2 – 4 There are several issues that need to be addressed before researchers or clinicians consider implementing this strategy. This study examined whether holding improves the
Hatice Mujde Ayık and Michael J. Griffin
When traveling by land, sea, or air, standing and walking passengers and crew experience various types of oscillatory perturbations that disturb their postural stability. To minimize instability caused by motion of a floor on which people are supported, it is necessary to understand how the
José Pino-Ortega, Alejandro Hernández-Belmonte, Carlos D. Gómez-Carmona, Alejandro Bastida-Castillo, Javier García-Rubio and Sergio J. Ibáñez
Defined as the ability to maintain the center of pressure of a body within the base of support with minimal postural sway through somatosensory information, 1 the postural stability is regulated by complex neurophysiological systems formed by the central and peripheral nervous system, the
Isaac Estevan, Sergio Gandia, Israel Villarrasa-Sapiña, José Luis Bermejo and Xavier García-Massó
Balance refers to the ability to stabilize the body to maintain posture with quiet standing while relying on integrating information from the visual, vestibular, and proprioceptive systems ( Mickle, Munro, & Steele, 2011 ). Consequently, balance or postural stability are not automatically regulated
Doris Bolt, René Giger, Stefan Wirth and Jaap Swanenburg
Ankle sprains demonstrate the highest incidence of all lower extremity injuries. 1 Recently, a lot of attention has been devoted to the dynamic postural stability and its influence on functional ankle instability. 2 Tests that challenge postural stability are required to identify deficits. 2
Hamid Bateni, Gina Leno, Rebeca Manjarres, Bailey Ouellette and Mark Wolber
Previous research has demonstrated that localized leg muscle fatigue induced by lower extremity exercises (e.g., squat jumps, sprints, and treadmill running) has an adverse effect on postural stability.
To assess the effect of cardiovascular fatigue induced by upper extremity exercise on postural stability.
Fourteen healthy young adults between the ages of 22 and 30 years (7 male and 7 female).
Participants performed an exercise protocol on an upper-body ergometer to induce cardiovascular fatigue.
Main Outcome Measures:
Postural sway, represented by center of pressure excursion, during bilateral standing in two different foot positions.
In a tandem standing position, mediolateral mean distance, root mean square distance, resultant power, and centroidal frequency increased signifcantly after inducement of cardiovascular fatigue.
Cardiovascular fatigue adversely affects postural stability.