Dynamic Balance During Human Movement: Measurement and Control Mechanisms

Abstract

Walking can be exceedingly complex to analyze due to highly nonlinear multibody dynamics, nonlinear relationships between muscle excitations and resulting muscle forces, dynamic coupling that allows muscles to accelerate joints and segments they do not span, and redundant muscle control. Walking requires the successful execution of a number of biomechanical functions such as providing body support, forward propulsion, and balance control, with specific muscle groups contributing to their execution. Thus, muscle injury or neurological impairment that affects muscle output can alter the successful execution of these functions and impair walking performance. The loss of balance control in particular can result in falls and subsequent injuries that lead to the loss of mobility and functional independence. Thus, it is important to assess the mechanisms used to control balance in clinical populations using reliable methods with the ultimate goal of improving rehabilitation outcomes. In this review, we highlight common clinical and laboratory-based measures used to assess balance control and their potential limitations, show how these measures have been used to analyze balance in several clinical populations, and consider the translation of specific laboratory-based measures from the research laboratory to the clinic.

Review of the Upright Balance Assessment Based on the Force Plate

“…Balance assessment methods can range from clinical balance assessments based on observational and scale methods to laboratory measurements based on kinematics and kinetics [ 80 ]. Observation methods include those such as the Romberg experiment.…”

“…In addition to the elderly, DGI has also been used to evaluate balance disorders in patients with Parkinson’s disease [ 87 ], multiple sclerosis [ 88 ], vestibular dysfunction [ 89 ], and other diseases. Non-instrumental tests such as observation method and scale method have upper limit effect, low sensitivity, and subjective evaluation [ 80 , 90 , 91 ].…”

The influence of cognitive load on balance control during steady-state walking

“…The majority of DT studies have focused on gait speed as the primary outcome measure [5], with few studies focusing on balance control [e.g., 1,11,16]. Whole-body angular momentum (H) provides a useful measure of balance control that has been validated in a number of populations and walking tasks [17]. However, H has not been assessed in DT conditions.…”

A model identification approach to quantify impact of whole-body vertical vibrations on limb compliant dynamics and walking stability

“…More recent studies employed these techniques for gait dynamic stability assessments in the forward direction of motion [26][27][28]. These methods are applicable to quantify gait stability/instability in all three anatomical directions, hence, overcome the limitations of previously reported assessments [24,29] which were reported in the anterior-posterior and medial-lateral directions (deficient to quantify the impact of vertical forces). This study extends the work done previously by considering vertical loading impacts while performing a level ground walk.…”