Assessment of postural control in children with cerebral palsy: a review.

This paper aimed to review studies that assessed postural control (PC) in children with cerebral palsy (CP) and describe the methods used to investigate postural control in this population. It also intended to describe the performance of children with CP in postural control. An extensive database search was performed using the keywords: postural control, cerebral palsy, children, balance and functionality. A total of 1065 papers were identified and 25 met the inclusion criteria. The survey showed that PC is widely studied in children with CP, with reliable methods. The link between postural control and functionality was also evident. However, a lack of studies was observed assessing postural control in these children by means of scales and functional tests, as well as exploring postural control during daily functional activities. Thus research addressing these issues can be a promising field for further research on postural control.

How Tai Chi improves balance: biomechanics of recovery to a walking slip in impaired seniors.

BACKGROUND AND AIMS: This study examined the effect of Tai Chi (TC) training on biomechanical responses to large, fast walking perturbations in balance-impaired seniors. METHODS: Twenty-two seniors (age 68-92, BERG 44 or less) with surgical interventions to knees, hips, and back were randomly divided into control or TC groups. Groups trained 1.5h/day, 5 days/week for 3 weeks. Controls received TC training after post-control testing. Subjects walked across a force plate triggered to move forward 15cm at 40cm/s at right heel strike (RHS). Kinematics, center of pressure (COP) and center of mass (COM) responses were measured. RESULTS: TC but not control training significantly reduced tripping (p

Neural mechanisms underlying balance improvement with short term Tai Chi training.

BACKGROUND AND AIMS: Though previous research has shown that Tai Chi reduces falls risk in older adults, no studies have examined underlying neural mechanisms responsible for balance improvement. We aimed to determine the efficacy of Tai Chi training in improving neuromuscular response characteristics underlying balance control in balance-impaired older adults. METHODS: Twenty-two balance-impaired older adults were randomly divided into Tai Chi (TC) or control groups. Nineteen subjects (age 68-92, BERG 44 or less) completed the study. TC training included repetitive exercises using TC motor and biomechanical strategies, techniques, and postural elements. Control training included axial mobility exercises, balance/awareness education and stress reduction. Groups trained 1.5 hours/day, 5 days/week for 3 weeks. After post-testing the control group received TC training. Subjects walked across a force plate triggered to move forward 15 cm at 40 cm/sec at heel strike. Tibialis anterior (TA) and medial gastrocnemius (GA) responses during balance recovery were measured with electromyograms (EMGs). Four clinical measures of balance were also recorded. RESULTS: TC subjects, but not controls, significantly reduced both TA response time from 148.92 +/- 45.11 ms to 98.67 +/- 17.22 ms (p < or = 0.004) and occurrence of co-contraction of antagonist muscles (p < or = 0.003) of the perturbed leg. Clinical balance measures also significantly improved after TC. CONCLUSIONS: TC enhanced neuromuscular responses controlling the ankle joint of the perturbed leg. Fast, accurate neuromuscular activation is crucial for efficacious response to slips or trips.

Postural dysfunction during standing and walking in children with cerebral palsy: what are the underlying problems and what new therapies might improve balance?

In this review we explore studies related to constraints on balance and walking in children with cerebral palsy (CP) and the efficacy of training reactive balance (recovering from a slip induced by a platform displacement) in children with both spastic hemiplegic and diplegic CP. Children with CP show (a) crouched posture, contributing to decreased ability to recover balance (longer time/increased sway); (b) delayed responses in ankle muscles; (c) inappropriate muscle response sequencing; (d) increased coactivation of agonists/antagonists. Constraints on gait include (a) crouched gait; (b) increased co-activation of agonists/antagonists; (c) decreased muscle activation; (d) spasticity. The efficiency of balance recovery can be improved in children with CP, indicated by both a reduction in the total center of pressure path used during balance recovery and in the time to restabilize balance after training. Changes in muscle response characteristics contributing to improved recovery include reductions in time of contraction onset, improved muscle response organization, and reduced co-contraction of agonists/antagonists. Clinical implications include the suggestion that improvement in the ability to recover balance is possible in school age children with CP.