Effect of sex and neck positions on hand grip strength in healthy normal adults: a cross-sectional, observational study

Head posture mediates the association of cognition with hand grip and pinch strength in older adults: an examination using structural equation modeling

BACKGROUND

The association of cognition with hand grip and pinch strength has been well-recognized in older adults. The authors sought to explore: (1) associations among forward head posture (FHP), cognition, and hand grip and pinch strength in older adults; and (2) the mediator role of FHP in these pathways using structural equation modeling (SEM).

METHODS

This cross-sectional study included 88 older adults (70.5% male; mean age = 68.75±3.87 years). Cognition was assessed by the Mini-Mental State Examination (MMSE), head posture by the Craniovertebral Angle (CVA) obtained from photographic analysis, hand grip strength by a handheld dynamometer, and pinch strength by a pinch meter. Using the two SEMs, a potential mediator role of the CVA was investigated. While the MMSE was addressed as an independent variable in both models, hand grip and pinch strength were addressed as dependent variables in model 1 and model 2, respectively.

RESULTS

The correlations between the CVA and MMSE (r = 0.310), hand grip strength (r = 0.370), and pinch strength (r = 0.274 to 0.292) were statistically significant (p < 0.001). In addition, significant associations were found between the MMSE and hand grip and pinch strength, ranging from 0.307 to 0.380 (p < 0.001). The mediation analysis showed that the standardized total (β = 0.41, p < 0.001) and indirect (mediated) effects (β = 0.12, p = 0.008) of the MMSE on hand grip strength were significant in model (1) The results were similar for model (2) The standardized total (β = 0.39, p = 0.001) and indirect effects (β = 0.10, p = 0.026) of the MMSE on pinch strength were significant. As a partial mediator in both models, the CVA explained 29% and 26% of the total effect in models 1 and 2, respectively.

CONCLUSIONS

The CVA was associated with the MMSE, hand grip strength, and pinch strength, and CVA partially mediates the association of the MMSE with grip and pinch strength in older adults, indicating that cognition had an effect on grip and pinch strength through an indirect path via head posture. This finding reveals that evaluating head posture and providing corrective therapeutic interventions as needed may be beneficial in reducing the negative impact of decreased cognition on motor functions in older adults.

Dynamometer based hand grip strength as a clinical tool for objective assessment of post-operative residual muscle weakness

Background and Aims:

Residual neuromuscular block continues to be a significant postoperative complication despite neuromuscular monitoring. This study aims to determine the applicability of a hand-held forced dynamometer for hand grip strength assessment as an objective measure of residual muscle weakness.

Methods:

The study included patients undergoing surgery under general anaesthesia. A demonstration was given to the patient on the usage of a dynamometer for handgrip strength and a peak expiratory flow meter for peak expiratory flow rate (PEFR) and baseline values were recorded. The parameters were monitored at 15 minutes post-extubation and again at intervals of 15 minutes until one hour, half-hourly until four hours, and hourly until six hours post-operatively. Paired t-test was used for comparison of baseline muscle strength and PEFR with the parameters at different time points. Association between muscle strength and PEFR was tested with the Pearson-correlation test.

Results:

Muscle strength was 50 to 60%, 75% and 100% of baseline at 15, 45 and 210 minutes after extubation, respectively. PEFR was 50 to 60%, 75% and 100% of baseline at 15, 60 and 180 minutes after extubation. The Pearson-correlation test established a positive correlation between handgrip strength and PEFR (correlation-coefficient 0.86).

Conclusion:

A significant reduction in the postoperative muscle strength can be detected using an objective forced dynamometer to measure handgrip strength even when train of four count has returned to unity and even when there are no clinical signs of muscle weakness. The residual muscle weakness is significant enough to affect the PEFR in the postoperative period.

Effect of forward head and rounded shoulder posture on hand grip strength in asymptomatic young adults: a cross-sectional study

Background

Forward head and rounded shoulder posture (FHRSP) is a common clinical postural misalignment. It leads to flexion posture of the spine which increases the amount of tension on the nerve roots, which inversely affects muscle strength and function of the upper extremity. So, this study was conducted to examine the effect of FHRSP on hand grip strength in asymptomatic young adults and to explore the relationship between the craniovertebral angle (CVA) and hand grip strength.

Results

There was no significant difference in hand grip strength between the groups (p = 0.812). There was no correlation between the CVA and right and left hand grip of the normal group (p = 0.840, 0.816 respectively), rounded shoulder posture (RSP) group (p = 0.523, 0.650 respectively), and FHRSP group (p = 0.855, 0.736 respectively). Regarding the right and left hand grip strength, there was no significant difference between the groups (p = 0.798, 0.826 respectively). The right hand grip strength was significantly higher than the left hand for all groups (p = 0.001).

Conclusion

This study displayed that hand grip strength was not affected by FHRSP nor RSP in asymptomatic young adults. Moreover, the degree of the CVA was not associated with an inverse effect on hand grip strength.

Influences of Neck and/or Wrist Pain on Hand Grip Strength of Industrial Quality Proofing Workers

Background

The aim of this study was to analyze the interaction between neck and/or wrist pain and hand grip strength (HGS) and to investigate factors (age, sex, neck disorders, and carpal tunnel syndrome) influencing the HGS of industrial quality proofing workers (N = 145).

Methods

Standardized questionnaires [Neck Disability Index (NDI), Boston Carpal Tunnel Questionnaire] were used to evaluate existing neck and/or wrist pain. HGS measurements were performed in different wrist positions.

Results

Significant differences between participants with and without neck pain were found in different wrist positions, in neutral wrist position right [without neck pain (n = 48) 46.34 (43.39 - 49.30); with neck pain (n = 97) 38.46 (36.20 - 40.72), F _(1,144)  = 16.82, p < 0.001, ŋ _p ² = 0.11] and left [without neck pain 44.06 (41.19 - 46.94); with neck pain 37.36 (35.13 - 39.58), F _(1,144)  = 12.70, p < 0.001, ŋ _p ² = 0.08]. A significant difference between participants with and without wrist pain was found for neutral wrist position right [without wrist pain (n = 105) 42.53 (40.37 - 44.70); with wrist pain (n = 40) 37.24 (33.56 - 40.91), F _(1,144)  = 6.41, p = 0.01, ŋ _p ² = 0.04]. Regression analysis showed significant results especially for steps two (age and weight, NDI) and three (age and weight, NDI, Boston Carpal Tunnel Questionnaire) for neutral position right (R² = 0.355, R² = 0.357, respectively).

Conclusion

Neck pain has an impact on HGS but should be evaluated in consideration of age and sex.