A review on muscle activation behaviour during gait in shallow water and deep-water running and surface electromyography procedures.

BACKGROUND: Surface electromyography (sEMG) can provide information on muscle activation patterns during gait. OBJECTIVES: To characterize electromyographic activity during gait in shallow water and during deep-water running compare to on land and to review and analyse underwater surface-electromyographic (sEMG) procedures. SEARCH METHODS: Eight databases (MEDLINE, EMBASE, WEB OF SCIENCE, SPORT Discus, CINAHL, SCOPUS, SCIELO, and LILACS) were searched from their inception to the December of 2019. SELECTION CRITERIA: The selected studies had to be related to electromyographic analysis of gait in an aquatic environment. DATA COLLECTION AND ANALYSIS: The studies that met the inclusion criteria were reviewed by two independent reviewers and divided into four groups. RESULTS: Ten studies met the inclusion criteria. Lower muscle activation was found with treadmill water walking compared to treadmill land walking. With deep-water running, the leg muscles (tibialis anterior and gastrocnemius lateralis) have lower muscle activation when compared to on land running, but the trunk and thigh muscles have higher activation. CONCLUSION: If gait is performed on an aquatic treadmill, the muscles assessed had lower muscle activation when compared to land. During deep-water running activities, lower activation of the distal leg muscles and a higher activation thigh muscles were found when compared to on land. Studies did not follow standard processes in sEMG procedures.

Posturography Comparison and Discriminant Analysis Between Individuals With and Without Chronic Low Back Pain.

OBJECTIVE: The aims of this study were to evaluate the center of pressure (CoP) in individuals with chronic low back pain (LBP) compared with matched controls and perform discriminant analysis to detect which CoP variables differentiate the groups. METHODS: Thirty-two participants with LBP and 33 matched controls were evaluated on a force plate in a bipedal static position for 30 seconds in 2 conditions: eyes open (EO) and eyes closed (EC). Two discriminant analyzes were performed to detect which CoP variables could discriminate between groups. RESULTS: Those with LBP had higher values (ie, poorer balance) for most variables compared with the control group. With EO, total displacement of sway (TDS) was as follows: LBP group (median [25%-75%]) 31.77 (26.39-41.79) cm, control group 27.21 (22.29-31.78) cm, P = .008 and area: LBP group 3.31 (2.33-4.68) cm2, control group 1.77 (1.3-2.71) cm2. With EC, TDS was as follows: LBP group 49.6 (39.65-68.15) cm, control group 38.77 (30.36; 45.65) cm, P = .003 and area: LBP group 4.68 (2.6-7.28) cm2, control group 2.4 (2.1-3.34) cm2. The discriminating variables in the EO condition were the TDS for the LBP group and the anteroposterior mean velocity for the control group, while in the EC condition they were mediolateral dispersion and area for the LBP group. CONCLUSION: Individuals with chronic LBP had worse postural control performance than matched controls, and it is possible to characterize those with and without LBP with CoP variables.

Postural Sway, Balance Confidence, and Fear of Falling in Women With Knee Osteoarthritis in Comparison to Matched Controls.

BACKGROUND: Osteoarthritis (OA) is a chronic degenerative disease that commonly affects the knee joints. Individuals older than 65 years of age with knee OA have a greater risk of falls. However, there has been limited examination of the parameters of postural sway (increased time, speed, and postural sway area [center of pressure{CoP}]), and OA of the knee. OBJECTIVES: The primary objective of this study was to determine whether the CoP variables discriminate between patients with knee OA and matched healthy volunteers, and to correlate the CoP variables with the Activities-Specific Balance Confidence Scale (ABC) and Falls Self-Efficacy Scale (FES). The secondary objective was to compare the CoP of older women with OA with a control group in bipedal support condition with eyes opened and closed. DESIGN: Cross-sectional study. SETTING: University Biomechanics Laboratory. PARTICIPANTS: A total of 22 participants were divided into the following 2 groups of 11 participants each: an OA group (mean = 68 years, standard deviation = 7.4 years) and a control group (mean = 66 years, standard deviation = 4.4 years). METHODS: Static postural balance was measured by a portable force platform. Data were collected in both visual conditions (eyes open and closed), in random order. Three attempts of 30 seconds were allowed for each participant on the force platform, with a 1-minute interval between attempts. MAIN OUTCOME MEASURE: Variables were the CoP total displacement of sway (TDS, in centimeters), anteroposterior amplitude displacement (APAD, in centimeters), medial-lateral amplitude displacement (MLAD, in centimeters), total mean velocity (TMV, in centimeters per second), and dispersion of the center of pressure (AREA, in centimeters squared). RESULTS: The postural sway analysis found statistically significant differences in the eyes open condition for the TDS (P = .020), APAD (P = .042), TMV (P = .010), and AREA (P = .045). In the discriminant analysis, none of the CoP variables were able to classify the groups (P = .15). The correlation analysis showed that only the AREA with eyes closed was associated with the ABC Scale (rho = -0.42). CONCLUSIONS: Women with knee OA had greater postural sway when compared with a control group for the eyes open condition. CoP variables could not discriminate between the groups. The AREA was negatively correlated with the ABC Scale, when the eyes were closed. LEVEL OF EVIDENCE: III.