The prevalence of rotator cuff weakness in patients with injured hands

Preoperative handgrip strength can predict early postoperative shoulder function in patients undergoing arthroscopic rotator cuff repair

BACKGROUND

Rotator cuff tears (RCTs) are a common musculoskeletal disorder, and arthroscopic rotator cuff repair (ARCR) is widely performed for tendon repair. Handgrip strength correlates with rotator cuff function; however, whether preoperative grip strength can predict functional outcomes in patients undergoing ARCR remains unknown. This study aimed to investigate the correlation between preoperative grip strength and postoperative shoulder function following ARCR.

METHODS

A total of 52 patients with full-thickness repairable RCTs were prospectively enrolled. Baseline parameters, namely patient characteristics and intraoperative findings, were included for analysis. Postoperative shoulder functional outcomes were assessed using the Quick Disabilities of the Arm, Shoulder, and Hand (QDASH) questionnaire and Constant-Murley scores (CMSs). Patients were followed up and evaluated at three and six months after ARCR. The effects of baseline parameters on postoperative outcomes were measured using generalized estimating equations.

RESULTS

At three and six months postoperatively, all clinical outcomes evaluated exhibited significant improvement from baseline following ARCR. Within 6 months postoperatively, higher preoperative grip strength was significantly correlated with higher CMSs (β = 0.470, p = 0.022), whereas increased numbers of total suture anchors were significantly correlated with decreased CMSs (β =  - 4.361, p = 0.03). Higher body mass index was significantly correlated with higher postoperative QDASH scores (β = 1.561, p = 0.03) during follow-up.

CONCLUSIONS

Higher baseline grip strength predicts more favorable postoperative shoulder function following ARCR. A preoperative grip strength test in orthopedic clinics may serve as a predictor for postoperative shoulder functional recovery in patients undergoing ARCR.

An electromyographic assessment pilot study on the reliability of the forearm muscles during multi-planar maximum voluntary contraction grip and wrist articulation in young males

BACKGROUND

Electromyographic systems are widely used in scientific and clinical practice. The reproducibility and reliability of these measures are crucial when conducting scientific research and collecting experimental data.

Comparison of anthropometric profile and handgrip strength between inter-university volleyball players and a reference group

Study aim: In a volleyball game, multiple elements can influence competitive success, e.g. height, arm span and other anthropometric variables. The present cross-sectional study was undertaken to find out whether any differences exist between Indian inter-university male and female volleyball players as well as between players and a reference group in terms of anthropometry and handgrip strength.

Materials and methods: The present cross-sectional research was conducted on 114 randomly selected Indian inter-university male (n = 50) and female (n = 64) volleyball players aged 18–25 years. An equal number of reference group individuals who did not participate in any exercise or training programme were also taken. Height, body weight, body mass index (BMI) (kg/m2), hand length, hand breadth, second digit length, fourth digit length, second and fourth digit ratio (2D/4D ratio), upper arm length, forearm length, total arm length, upper arm circumference, hip circumference; humerus and femur biepicondylar diameters, handgrip strength (dominant/non-dominant), arm muscle area, arm area, arm fat area, arm fat index, % body fat, and % lean body mass were measured with equipment including an anthropometer, sliding caliper, handgrip dynamometer and skinfold caliper using standard techniques. The data were analysed using SPSS version 17.0. Student’s t-test was applied for the comparison of data between players and the reference group. Differences between the groups were analysed using the oneway ANOVA test. Bonferroni post hoc test was applied after application of the ANOVA test. Effect size was also calculated. Statistical significance (p < 0.05) was indicated using a 5% level of probability.

Results: Male volleyball players had higher mean values in height, body weight, hand length, hand breadth, second and fourth digit length, dominant and non-dominant handgrip strength, humerus and femur biepicondylar diameter, upper arm length, forearm length and total arm length, arm muscle area, arm area and percent lean body mass than the reference group. Similar findings were observed between female players and the reference group also. Statistically significant differences (p < 0.05–0.001) were also observed between male and female players except BMI, 2D/4D ratio, and arm fat area. These findings were supported by the effect size (η) calculations.

Conclusion: Volleyball players had better height, weight, hand and arm anthropometrics, handgrip strength and % lean body mass as compared to the reference group. Significant differences were found in anthropometry and handgrip strength between players and reference group individuals, suggesting that these findings could be very useful for player selection and talent identification in sports.

Effects of hand grip exercise on shoulder joint internal rotation and external rotation peak torque

BACKGROUND AND OBJECTIVES

The goal of this study is to analyze the effects of hand grip training on shoulder joint internal rotation (IR)/external rotation (ER) peak torque for healthy people.

METHODS

The research was conducted on 23 healthy adults in their 20 s-30 s who volunteered to participate in the experiment. Hand grip power test was performed on both hands of the research subjects before/after the test to study changes in hand grip power. Isokinetic machine was used to measure the concentric IRPT (internal rotation peak torque) and concentric ERPT (external rotation peak torque) at the velocity of 60°/sec, 90°/sec, and 180°/sec before/after the test. Hand grip training was performed daily on the subject's right hand only for four weeks according to exercise program. Finally, hand grip power of both hands and the maximum torque values of shoulder joint IR/ER were measured before/after the test and analyzed.

RESULTS

There was a statistically significant difference in the hand grip power of the right hand, which was subject to hand grip training, after the experiment. Also, statistically significant difference for shoulder ERPT was found at 60°/sec.

CONCLUSION

Hand grip training has a positive effect on shoulder joint IRPT/ERPT and therefore can help strengthen muscles around the shoulder without using weight on the shoulder. Consequently, hand grip training would help maintain strengthen the muscles around the shoulder in the early phase of rehabilitation process after shoulder surgery.

Do changes in hand grip strength correlate with shoulder rotator cuff function?

BACKGROUND

Shoulder pain as a result of rotator cuff pathology is one of the most common musculoskeletal complaints presenting within primary care. Assessment of hand grip strength has been proposed as an indicator of rotator cuff function. This experimental study assessed the relationship between grip strength and shoulder lateral rotator muscle strength in a number of different shoulder positions, aiming to investigate whether such a relationship existed and whether grip strength could be used as a functional assessment tool for the posterior cuff.

METHODS

Twenty-seven healthy, physically active, volunteers (19 males, eight females) with no history of shoulder, upper limb or neck injury comprised the study group. The mean (SD) age was 19.8 (5.7) years (range 18 years to 23 years). Grip strength (measured with hand grip dynamometer) and lateral rotator strength (measured with a hand held dynamometer) was measured at neutral, 90° abduction, and 90° abduction with 90° external rotation.

RESULTS

The correlation between grip strength and shoulder lateral rotation strength ranged between r = 0.91 (r (2 )= 0.84) and r = 0.72 (r (2 )= 0.52) across all positions.

CONCLUSIONS

A strong correlation between grip strength and lateral rotator strength was shown at all positions for both left and right hands, suggesting that assessment of grip strength could be used as a rotator cuff monitor of recruitment function.

Correlations of Handgrip Strength with Selected Hand-Arm-Anthropometric Variables in Indian Inter-university Female Volleyball Players

Purpose

The purpose of this study was to estimate the dominant handgrip strength and its correlations with some hand and arm anthropometric variables in 101 randomly selected Indian inter-university female volleyball players aged 18-25 years (mean age 20.52±1.40) from six Indian universities.

Methods

Three anthropometric variables, i.e. height, weight, BMI, two hand anthropometric variables, viz. right and left hand width and length, four arm anthropometric variables, i.e. upper arm length, lower arm length, upper extremity length, upper arm circumference and dominant right and non-dominant handgrip strength were measured among Indian inter-university female volleyball players by standard anthropometric techniques.

Results

The findings of the present study indicated that Indian female volleyball players had higher mean values in eleven variables and lesser mean values in two variables than their control counterparts, showing significant differences (P<0.032-0.001) in height (t=2.63), weight (t=8.66), left hand width (t=2.10), left and right hand length (t=9.99 and 10.40 respectively), right upper arm length (t=8.48), right forearm length (t=5.41), dominant (right) and non-dominant (left) handgrip strength (t=9.37 and 6.76 respectively). In female volleyball players, dominant handgrip strength had significantly positive correlations (P=0.01) with all the variables studied.

Conclusion

It may be concluded that dominant handgrip strength had strong positive correlations with all the variables studied in Indian inter-university female volleyball players.

Upper limb muscle imbalance in tennis elbow: a functional and electromyographic assessment

The purpose of this study was to investigate strength, fatigability, and activity of upper limb musculature to elucidate the role of muscular imbalance in the pathophysiology of tennis elbow. Sixteen patients clinically diagnosed with tennis elbow, recruited from a university hospital upper limb orthopedic clinic, were compared with 16 control subjects with no history of upper limb musculoskeletal problem, recruited from university students and staff. Muscle strength was measured for grip, metacarpophalangeal, wrist, and shoulder on both sides. Electromyographic activity (RMS amplitude) and fatigue characteristics (median frequency slope) of five forearm and two shoulder muscles were measured during isometric contraction at 50% maximum voluntary contraction. All strength measurements showed dominance difference in C, but none in TE. In tennis elbow compared to controls, hand/wrist and shoulder strength and extensor carpi radialis (ECR) activity were reduced (p < 0.05), while fatigue was normal. A global upper limb weakness exists in tennis elbow. This may be due to disuse and deconditioning syndrome caused by fear avoidance, and needs to be addressed in prevention and treatment. Activation imbalance among forearm muscles (reduced extensor carpi radialis activity) in tennis elbow, probably due to protective pain-related inhibition, could lead to a widespread upper limb muscle imbalance.