A new methodology based on functional principal component analysis to study postural stability post-stroke

Effects of muscle strength in different parts of adolescent standing long jump on distance based on surface electromyography

Objective: To reveal the influence of muscle strength in different parts of the body on the distance of standing jump, to establish the key force phases of muscle strength in different parts, and to improve the recognition of movement norms. Methods: VICON infrared three-dimensional motion capture acquisition and analysis system and Noraxon Ultium surface electromyography acquisition and analysis system were used to complete the surface electromyography signal acquisition of 18 randomly selected subjects performing standing long jump. Results: 1) Triceps brachii, anterior deltoid, latissimus dorsi, semitendinosus, rectus femoris, upper trapezius, pectoralis major, and biceps femoris had significant effects on standing jump distance. 2) From the point of view of the key exertion phase of the standing jump mainly affecting the muscle group; the main exertion phase of the semitendinosus occurs from the rising stage to the descending stage; the rectus femoris, triceps, and latissimus dorsi occur during the ascending phase of the flight; the anterior deltoid muscle occurs in the transition stage from rising to falling in the air; the trapezius muscle occurs in the transition stage from pre-swing to kick-off. Conclusion: 1) From the regression analysis of the measured muscles on the distance of each stage of standing long jump, deltoid muscle strength is conducive to the improvement of standing long jump distance, which further indicates the importance of upper limb deltoid muscle strength. 2) Through time series analysis, it is found that the force performance of the rectus femoris muscle at this stage can be used as the main identification parameter of standing long jump, and can effectively distinguish different types of movements.

Trunk training following stroke

BACKGROUND

Previous systematic reviews and randomised controlled trials have investigated the effect of post-stroke trunk training. Findings suggest that trunk training improves trunk function and activity or the execution of a task or action by an individual. But it is unclear what effect trunk training has on daily life activities, quality of life, and other outcomes.

OBJECTIVES

To assess the effectiveness of trunk training after stroke on activities of daily living (ADL), trunk function, arm-hand function or activity, standing balance, leg function, walking ability, and quality of life when comparing with both dose-matched as non-dose-matched control groups.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE, Embase, and five other databases to 25 October 2021. We searched trial registries to identify additional relevant published, unpublished, and ongoing trials. We hand searched the bibliographies of included studies.

SELECTION CRITERIA

We selected randomised controlled trials comparing trunk training versus non-dose-matched or dose-matched control therapy including adults (18 years or older) with either ischaemic or haemorrhagic stroke. Outcome measures of trials included ADL, trunk function, arm-hand function or activity, standing balance, leg function, walking ability, and quality of life.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two main analyses were carried out. The first analysis included trials where the therapy duration of control intervention was non-dose-matched with the therapy duration of the experimental group and the second analysis where there was comparison with a dose-matched control intervention (equal therapy duration in both the control as in the experimental group).  MAIN RESULTS: We included 68 trials with a total of 2585 participants. In the analysis of the non-dose-matched groups (pooling of all trials with different training duration in the experimental as in the control intervention), we could see that trunk training had a positive effect on ADL (standardised mean difference (SMD) 0.96; 95% confidence interval (CI) 0.69 to 1.24; P < 0.001; 5 trials; 283 participants; very low-certainty evidence), trunk function (SMD 1.49, 95% CI 1.26 to 1.71; P < 0.001; 14 trials, 466 participants; very low-certainty evidence), arm-hand function (SMD 0.67, 95% CI 0.19 to 1.15; P = 0.006; 2 trials, 74 participants; low-certainty evidence), arm-hand activity (SMD 0.84, 95% CI 0.009 to 1.59; P = 0.03; 1 trial, 30 participants; very low-certainty evidence), standing balance (SMD 0.57, 95% CI 0.35 to 0.79; P < 0.001; 11 trials, 410 participants; very low-certainty evidence), leg function (SMD 1.10, 95% CI 0.57 to 1.63; P < 0.001; 1 trial, 64 participants; very low-certainty evidence), walking ability (SMD 0.73, 95% CI 0.52 to 0.94; P < 0.001; 11 trials, 383 participants; low-certainty evidence) and quality of life (SMD 0.50, 95% CI 0.11 to 0.89; P = 0.01; 2 trials, 108 participants; low-certainty evidence). Non-dose-matched trunk training led to no difference for the outcome serious adverse events (odds ratio: 7.94, 95% CI 0.16 to 400.89; 6 trials, 201 participants; very low-certainty evidence). In the analysis of the dose-matched groups (pooling of all trials with equal training duration in the experimental as in the control intervention), we saw that trunk training had a positive effect on trunk function (SMD 1.03, 95% CI 0.91 to 1.16; P < 0.001; 36 trials, 1217 participants; very low-certainty evidence), standing balance (SMD 1.00, 95% CI 0.86 to 1.15; P < 0.001; 22 trials, 917 participants; very low-certainty evidence), leg function (SMD 1.57, 95% CI 1.28 to 1.87; P < 0.001; 4 trials, 254 participants; very low-certainty evidence), walking ability (SMD 0.69, 95% CI 0.51 to 0.87; P < 0.001; 19 trials, 535 participants; low-certainty evidence) and quality of life (SMD 0.70, 95% CI 0.29 to 1.11; P < 0.001; 2 trials, 111 participants; low-certainty evidence), but not for ADL (SMD 0.10; 95% confidence interval (CI) -0.17 to 0.37; P = 0.48; 9 trials; 229 participants; very low-certainty evidence), arm-hand function (SMD 0.76, 95% CI -0.18 to 1.70; P = 0.11; 1 trial, 19 participants; low-certainty evidence), arm-hand activity (SMD 0.17, 95% CI -0.21 to 0.56; P = 0.38; 3 trials, 112 participants; very low-certainty evidence). Trunk training also led to no difference for the outcome serious adverse events (odds ratio (OR): 7.39, 95% CI 0.15 to 372.38; 10 trials, 381 participants; very low-certainty evidence). Time post stroke led to a significant subgroup difference for standing balance (P < 0.001) in non-dose-matched therapy. In non-dose-matched therapy, different trunk therapy approaches had a significant effect on ADL (< 0.001), trunk function (P < 0.001) and standing balance (< 0.001). When participants received dose-matched therapy, analysis of subgroup differences showed that the trunk therapy approach had a significant effect on ADL (P = 0.001), trunk function (P < 0.001), arm-hand activity (P < 0.001), standing balance (P = 0.002), and leg function (P = 0.002). Also for dose-matched therapy, subgroup analysis for time post stroke resulted in a significant difference for the outcomes standing balance (P < 0.001), walking ability (P = 0.003) and leg function (P < 0.001), time post stroke significantly modified the effect of intervention.  Core-stability trunk (15 trials), selective-trunk (14 trials) and unstable-trunk (16 trials) training approaches were mostly applied in the included trials.

AUTHORS' CONCLUSIONS

There is evidence to suggest that trunk training as part of rehabilitation improves ADL, trunk function, standing balance, walking ability, upper and lower limb function, and quality of life in people after stroke. Core-stability, selective-, and unstable-trunk training were the trunk training approaches mostly applied in the included trials. When considering only trials with a low risk of bias, results were mostly confirmed, with very low to moderate certainty, depending on the outcome.

EVALUATION OF POSTURAL BALANCE INDICATORS IN HEALTHY INDIVIDUALS

OBJECTIVE

The aim: To determine and generalize the indicators of stabilometry in healthy individuals for their further use as a control group in studies of pathologies of the musculoskeletal system.

PATIENTS AND METHODS

Materials and methods: The study was conducted on a stable platform with biofeedback TYMO (Tyromotion). 30 male and female patients aged 18-25 years participated in the study. The following indicators were studied : distance traveled, medial-lateral deviation, anterior-posterior deviation, area of the statokinesiogram (COF), average speed, feedback system, Romberg index. Stabilometry was performed in a bipodal position, standing, in four functional positions: on a hard surface with eyes open and closed, on a soft surface with eyes open and closed.

RESULTS

Results: The reference values of the stabilometric parameters: the traveled distance, medio-lateral deviation, anterior-posterior deviation, the area of the statokinesiogram, the average speed, the feedback system, the Romberg index in healthy individuals aged 18-25 years were determined . When evaluating the feedback system, it was established that the visual component was 34% (32.0; 36.0), the vestibular 34% (32.0; 35.0), the somatosensory 33% (30.0; 36.0). The reflex-driven index was 0.55 (0.46, 0.62), the central nervous system (CNS)-driven index was 1.55 (1.25, 1.89) . The Romberg index M1/ M2 was 0.94 (0.78, 1.07), M2/M3 was 0.98 (0.86, 1.10).

CONCLUSION

Conclusions: The obtained indicators of movement in the sagittal plane, the area of the statokinesiogram, the average speed of movement, the feedback system (visual, vestibular, proprioceptive (somatosensory) components), the Romberg index (RI) can be considered reference values for healthy individuals aged 18-25 years .

Applying the Minimal Detectable Change of a Static and Dynamic Balance Test Using a Portable Stabilometric Platform to Individually Assess Patients with Balance Disorders

Balance disorders have a high prevalence among elderly people in developed countries, and falls resulting from balance disorders involve high healthcare costs. Therefore, tools and indicators are necessary to assess the response to treatments. Therefore, the aim of this study is to detect relevant changes through minimal detectable change (MDC) values in patients with balance disorders, specifically with vertigo. A test-retest of a static and dynamic balance test was conducted on 34 healthy young volunteer subjects using a portable stabilometric platform. Afterwards, in order to show the MDC applicability, eight patients diagnosed with balance disorders characterized by vertigo of vestibular origin performed the balance test before and after a treatment, contrasting the results with the assessment by a specialist physician. The balance test consisted of four tasks from the Romberg test for static balance control, assessing dynamic postural balance through the limits of stability (LOS). The results obtained in the test-retest show the reproducibility of the system as being similar to or better than those found in the literature. Regarding the static balance variables with the lowest MDC value, we highlight the average velocity of the center of pressure (COP) in all tasks and the root mean square (RMS), the area, and the mediolateral displacement in soft surface, with eyes closed. In LOS, all COP limits and the average speed of the COP and RMS were highlighted. Of the eight patients assessed, an agreement between the specialist physician and the balance test results exists in six of them, and for two of the patients, the specialist physician reported no progression, whereas the balance test showed worsening. Patients showed changes that exceeded the MDC values, and these changes were correlated with the results reported by the specialist physician. We conclude that (at least for these eight patients) certain variables were sufficiently sensitive to detect changes linked to balance progression. This is intended to improve decision making and individualized patient monitoring.

Cross-sectional study of quadriceps properties and postural stability in patients with chronic stroke and limited vs. non-limited community ambulation

Background: Changes in the paretic-side metabolism post-stroke and quadriceps muscle mechanical properties favour muscle wasting, affecting postural instability and walking impairment. Further clarification is needed in subjects post-stroke who show limited or non-limited community ambulation. Objectives: To analyze between-limb differences in quadriceps muscle thickness, strength and thigh cutaneous temperature, as well as investigate postural stability in subjects with chronic stroke and limited vs. non-limited community ambulation and compared against healthy controls. Methods: In this controlled cross-sectional study, 26 participants with chronic hemiparesis post-stroke (divided in a slow gait group (SG<0.8 m/s) (n = 13) and a fast gait group with full community ambulation speed (FG≥0.8 m/s)) and 18 healthy people were recruited. Thigh surface temperature, rectus femoris (RF) and vastus intermedius (VI) muscles thickness, quadriceps' isometric maximal voluntary contraction and postural stability were measured. Results: The SG presented significantly lower RF (P = .019) and VI (P = .006) muscle thickness, less peak force (P < .001) and lower temperature (P = .002) in the paretic vs the non-paretic limb. The FG showed significantly lower VI thickness (P = .036) and peak force (P < .001) in the paretic vs the non-paretic limb. Regarding balance, all indices were worse in the SG versus the FG and CG. Conclusions: Subjects of the FG, despite showing full community ambulation speed, had less quadriceps strength and VI muscle thickness but not RF muscle wasting in the paretic limb. The paretic VI muscle wasting may be an important factor to reach normal walking. The SG showed between-limb differences in all the studied variables and the worst postural stability.