Best Core Stabilization for Anticipatory Postural Adjustment and Falls in Hemiparetic Stroke.

OBJECTIVES: To compare the effects of conventional core stabilization and dynamic neuromuscular stabilization (DNS) on anticipatory postural adjustment (APA) time, balance performance, and fear of falls in chronic hemiparetic stroke. DESIGN: Two-group randomized controlled trial with pretest-posttest design. SETTING: Hospital rehabilitation center. PARTICIPANTS: Adults with chronic hemiparetic stroke (N=28). INTERVENTIONS: Participants were randomly divided into either conventional core stabilization (n=14) or DNS (n=14) groups. Both groups received a total of 20 sessions of conventional core stabilization or DNS training for 30 minutes per session 5 times a week during the 4-week period. MAIN OUTCOME MEASURES: Electromyography was used to measure the APA time for bilateral external oblique (EO), transverse abdominis (TrA)/internal oblique (IO), and erector spinae (ES) activation during rapid shoulder flexion. Trunk Impairment Scale (TIS), Berg Balance Scale (BBS), and Falls Efficacy Scale (FES) were used to measure trunk movement control, balance performance, and fear of falling. RESULTS: Baseline APA times were delayed and fear of falling was moderately high in both the conventional core stabilization and DNS groups. After the interventions, the APA times for EO, TrA/IO, and ES were shorter in the DNS group than in the conventional core stabilization group (P<.008). The BBS and TIS scores (P<.008) and the FES score (P<.003) were improved compared with baseline in both groups, but FES remained stable through the 2-year follow-up period only in the DNS group (P<.003). CONCLUSIONS: This is the first clinical evidence highlighting the importance of core stabilization exercises for improving APA control, balance, and fear of falls in individuals with hemiparetic stroke.

Unipedal postural stability in nonathletes with core instability after intensive abdominal drawing-in maneuver.

CONTEXT: The exact neuromechanical nature and relative contribution of the abdominal drawing-in maneuver (ADIM) to postural instability warrants further investigation in uninjured and injured populations. OBJECTIVE: To determine the effects of the ADIM on static core and unipedal postural stability in nonathletes with core instability. DESIGN: Controlled laboratory study. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 19 nonathletes (4 women: age = 22.3 ± 1.3 years, height = 164.0 ± 1.7 cm, mass = 56.0 ± 4.6 kg; 15 men: age = 24.6 ± 2.8 years, height = 172.6 ± 4.7 cm, mass = 66.8 ± 7.6 kg) with core instability. INTERVENTION(S): Participants received ADIM training with visual feedback 20 minutes each day for 7 days each week over a 2-week period. MAIN OUTCOME MEASURES(S): Core instability was determined using a prone formal test and measured by a pressure biofeedback unit. Unipedal postural stability was determined by measuring the center-of-pressure sway and associated changes in the abdominal muscle-thickness ratios. Electromyographic activity was measured concurrently in the external oblique, erector spinae, gluteus medius, vastus medialis oblique, tibialis anterior, and medial gastrocnemius muscles. RESULTS: All participants initially were unable to complete the formal test. However, after the 2-week ADIM training period, all participants were able to reduce the pressure biofeedback unit by a range of 4 to 10 mm Hg from an initial 70 mm Hg and maintain it at 60 to 66 mm Hg with minimal activation of the external oblique (t(18) = 3.691, P = .002) and erector spinae (t(18) = 2.823, P = .01) muscles. Monitoring of the pressure biofeedback unit and other muscle activations confirmed that the correct muscle contraction defining the ADIM was accomplished. This core stabilization was well maintained in the unipedal-stance position, as evidenced by a decrease in the center-of-pressure sway measures (t(18) range, 3.953-5.775, P < .001), an increased muscle-thickness ratio for the transverse abdominis (t(18) = -2.327, P = .03), and a reduction in external oblique muscle activity (t(18) = 3.172, P = .005). CONCLUSIONS: We provide the first evidence to highlight the positive effects of ADIM training on core and postural stability in nonathletes with core instability.