Comparison of landing kinematics and kinetics between experienced and novice volleyball players during block and spike jumps

BACKGROUND

The practice of volleyball requires many jumps. During landing, anterior cruciate ligament injuries may occur with high-risk lower limb kinematics and kinetics. Differences in landing strategies between experienced and novice volleyball players have not been fully explored. The purpose of the study was to compare lower limb kinematics and kinetics in experienced and novice volleyball players when performing volleyball specific jumps.

METHODS

A total of 30 healthy males, 15 experienced and 15 novice volleyball players, participated in the study. Participants performed block and spike jumps at a controlled jump height. Hip, knee and ankle joints angles at initial ground contact and ranges of motion in the sagittal plane, knee joint angles and moments in the frontal plane, vertical ground reaction force peak and loading rate were analyzed to investigate the expertise effect.

RESULTS

Experienced volleyball players landed with larger ankle dorsiflexion range of motion compared to novices. For the spike jump, experienced players landed with larger ankle plantarflexion angles at initial contact and larger ankle dorsiflexion ranges of motion, and for the block jump, they landed with larger knee flexion ranges of motion. Experienced players jumped significantly higher than novices. No difference was found in vertical ground reaction force peaks and loading rates.

CONCLUSIONS

Although the experienced group jumped higher than the novice group, no difference was found in ground reaction force parameters. These findings highlight that the experience of volleyball players acquired during regular trainings and competitions may play an important role in landing kinematics and kinetics to reduce the injury risk.

Safety and reliability of dobutamine stress echocardiography in pediatric and young adult patients with coronary arteries abnormalities

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study was conducted with the support of Regione Marche, Italy

Background

Risk stratification in coronary arteries abnormalities (CAA), both anomalous aortic origin of a coronary artery (AAOCA) and myocardial bridges (MBs), is still challenging. A reliable method to detect myocardial ischemia is missing in these anomalies. We studied the safety and feasibility of dobutamine stress echocardiography (DSE), compared with exercise stress echocardiography (ESE), in pediatric and young adult patients with CAA.

Methods

In 2019-21, N = 27 CAA [median age 16 years (Q1–Q3: 11, 22)] (n= 23 AAOCA, n = 4 MBs) were assessed. ESE was performed 1-2 days before the DSE examination, double-blinded for examiners and patients. Hemodynamic response and major (cardiac arrest, myocardial infarction, ventricular arrhythmia) and minor [hypertension (≥ 200/120 mmHg), paradoxical bradycardia, chest pain, nausea/vomiting, skin rash, anxiety, dizziness, dyspnea] events were recorded. Differences between rest/stress and DSE/ESE for wall motion abnormalities (WMA) and global longitudinal strain (GLS) were evaluated. Inter-observer agreement was also tested using the kappa (k) coefficient.

Results

Heart rate and blood pressure increased significantly from baseline (p < 0.001) in both DSE and ESE exams. Only DSE tests reached a heart rate ≥ 150 bpm (p < 0.001), while younger patients barely reached the heart rate target and frequently showed less compliance to the test. No patient had major events, while 5 (18.5%) had minor events, the majority during DSE. Inducible WMA were observed only at DSE examinations. Inter-observer agreement for WMA and GLS changes was good for both examinations (95%, k = 0.85, p < 0.001).

Conclusions

DSE is feasible in pediatric and young adult patients with AAOCA and MBs to assess inducible WMA and GLS rest/stress changes. It can be performed safely with a low incidence of major/minor events, with a better performance when compared to ESE. DSE is potentially a valuable test for detecting myocardial ischemia and probably helpful in managing CAA patients.

Ross procedure and aortic valve repair: long-term echocardiographic outcomes, quality of life and physical activity of different aortic valve surgery procedures

Funding Acknowledgements

Type of funding sources: None.

Background

 To compare long-term outcomes of aortic valve repair (AVr) and pulmonary autograft replacement (Ross procedure) in terms of echocardiographic parameters, quality of life (QoL), physical activity (PA).

Methods

 In 2005-19, 129 patients (median age 22 [13, 33 IQR], 75% males) underwent aortic surgery in our Department: 40 were Ross (22 years [19, 51 IQR]), 67 AVr (17 years [1, 50 IQR]) and 22 aortic valve replacements (52 years [30, 80 IQR]). We focused on Ross and AVr. Retrospectively, relevant data were collected from medical records and phone re-calls. Physical activity (spontaneous and active) and QoL were assessed utilizing the IPAQ and SF-36 questionnaires. All patients underwent echocardiography pre/post-surgery and the follow-up lasted 12 ± 4 years.

Results

 At the baseline, Ross patients had more aortic stenosis than insufficiency (P = 0.045). At the follow-up, Ross procedures presented more right-ventricle and aortic annulus dilatation (P = 0.002 and P = 0.030, respectively), but higher left-ventricular global longitudinal strain (LV GLS: 18 ± 3.2 % vs. 16 ± 3.3, P = 0.0027). Conversely, AVr experienced more re-do operations (Log-rank P = 0.005). Ross reported better QoL (SF-36: 0.8 ± 0.07 vs. 19 ± 0.4, P-0.045) and were also more active in daily PA (IPAQ ≥ 2500 Mets: 63.8% vs. 6%; P = 0.006). Ross patients practiced more sports activities than AVr (P = 0.011).

Conclusions

 In a relatively small cohort of young and adults post aortic surgery patients, Ross procedures had better prognosis in terms of re-do operations; presented better ventricular function, as assessed by LV GLS. Ross patients had better long-term QoL and showed more spontaneous PA and involvement in sports activity.

A new approach for endoscopic neurolysis of the suprascapular nerve at the spinoglenoid notch: A preliminary cadaver study

The suprascapular nerve (SSN) can become compressed at its 2 scapular attachments: the suprascapular and the spinoglenoid notch. The objective of this study was to describe a new arthroscopic approach for SSN neurolysis at the spinoglenoid notch. Ten cadaver shoulders were used. Two were dissected to simulate the "classical" arthroscopic approach and to help in the creation of a new "direct medial retrospinal" approach. Eight other shoulders were used to validate this new approach, with control of the whole juxta-glenoid course of the SSN as criterion of success. The retrospinal posterior approach allowed the entire juxta-glenoid segment of the SSN to be explored in 6 cases out of 8. One exploration was incomplete, another not feasible. SSN neurolysis at the spinoglenoid notch was feasible in cadavers on a retrospinal approach.

[Analytic study of hopes and perceptions of second-year medical school students during gross anatomy laboratory cessions]

INTRODUCTION

Using an anonymous questionnaire, this study aimed to assess hopes and perceptions of second-year medical school students faced to gross anatomy dissections and to appreciate the status of dissection within the others anatomical teaching tools.

MATERIALS AND METHODS

The questionnaire was distributed among 210 second-year medical students during gross anatomy dissections. The first part of the questionnaire aimed to assess perceptions of students before dissections while the second part aimed to position dissection in their anatomical teaching cursus.

RESULTS

Within the 210 students participating to the study, 70 (45%) had not seen a dead human body before the laboratory cession. The main stressful factors were technical difficulties encountered during dissection more than embarrassment in front of the cadaver. The level of stress was significantly higher in female students. Hand, neck and gluteal regions were the most stressful regions reported by students. Students considered that gross anatomy dissection was a key ritual experience crucial for their formation that should not be only proposed to senior practitioners.

CONCLUSION

This study illustrates the invariable interest of medical students for gross anatomy laboratory cessions that permit a first technical experience, faced to the death.

Interest of complementary inferior glenohumeral ligament fixation in capsulo-labral repair for shoulder instability: A biomechanical study

Arthroscopic repair of Bankart lesions is part of the arsenal available to the shoulder surgeon to manage chronic anterior instability of the shoulder. Despite improvements in technique, rates of recurrence remain high. Some factors relate to the patients and their lesions, others to technique.The hypothesis that insufficient repair may be the cause of failure in Bankart arthroscopy was investigated in an anatomic and biomechanical study. Bankart lesions were made on 12 cadaver shoulders and repaired using two suture techniques. The aim was to investigate whether there was any biomechanical interest in reinforcing the labrum and capsule suture by a complementary inferior gleno-humeral ligament (IGHL) suture to double the labral repair. No significant difference in overall resistance was found between the two techniques. Failure generally started from the superior suture, and the present findings suggest that special attention should be paid to superior reinsertion. In the present model, complementary IGHL fixation did not alter the biomechanics of repair. Failure of repair can be traced to the superior suture.

Effect of object width on precision grip force and finger posture

This study aimed to define the effect of object width on spontaneous grasp. Participants held objects of various masses (0.75 to 2.25 kg) and widths (3.5 to 9.5 cm) between thumb and index finger. Grip force, maximal grip force and corresponding finger postures were recorded using an embedded force sensor and an optoelectronic system, respectively. Results showed that index finger joints varied to accommodate the object width, whereas thumb posture remained constant across conditions. For a given object mass, grip force increased as a function of object width, although this result is not dictated by the laws of mechanics. Because maximal grip force also increased with object width, we hypothesise that participants maintain a constant ratio between grip force and their maximal grip force at each given width. Altogether we conclude that when the task consists in manipulating objects/tools, the optimal width is different than when maximal force exertions are required.

Exercise physiology in COPD

Multiple mechanisms contribute to exercise limitation in chronic obstructive pulmonary disease (COPD). The ability to increase ventilation during exercise is reduced; the more advanced the disease, the more impaired the exercise tolerance is. However, factors other than ventilatory limitation play an important role in reducing the exercise capacity in COPD. Data implicating peripheral muscle atrophy and muscle weakness as cofactors have been reported in individuals with advanced disease. At this stage daily activities are curtailed to avoid exertional respiratory discomfort. Recent studies have demonstrated that the muscle aerobic capacity of stable hypoxemic COPD patients is impaired; oxygen uptake (V'O2) kinetics and 31P magnetic resonance spectroscopy studies have shown that these patients rely heavily on non-aerobic energy sources even during moderate, sustained workloads. Finally, early occurrence of metabolic acidosis has been demonstrated in patients with mild to severe COPD during exercise. Inadequate tissue oxygenation appears to result from a defect in peripheral oxygen utilization rather than from a reduction in O2 bulk flow. Peripheral factors may include: a) impaired diffusive conductance for O2 between red cells and mitochondria; b) heterogeneous distribution of O2 bulk flow within the exercising muscle fibers; c) inertia of the oxidative processes at the cellular level; d) changes in distribution of muscle fibers, e) reduction in muscle aerobic enzymes; and f) poor nutritional status. Since muscle dysfunction has an important role in the development of exercise intolerance, physical rehabilitation is more and more used as part of the treatment of COPD. The aim of this review is to briefly discuss current views on the mechanisms responsible for the reduced ability to exercise and the rationale for exercise rehabilitation in COPD patients.

Skeletal muscle dysfunction in chronic obstructive pulmonary disease

During the last decade evidence has been accumulated on the role of skeletal muscle dysfunction in reducing exercise capacity and affecting the quality of life of patients with chronic obstructive pulmonary disease (COPD). An appreciable body of research has helped to identify morphological and biochemical alterations, physiological consequences, and possible therapeutic interventions. There are, however, still many areas of uncertainty. For example it is not clear how much of the alterations are within the muscle itself or the consequence of the altered environment in which the muscle works. Similarly it is not clear how much of the impairment is simply due to aging and chronic inactivity. Another key issue is the possible additive effect of drugs often used in COPD patients, such as steroids, beta 2-agonist and cyclosporin. A specific additional layer of complexity comes from nutritional considerations and in particular loss of muscle mass which not infrequently accompanies severe disease and even greater exercise intolerance. Studies on the effects of training or other therapeutic interventions have shown that muscle dysfunction is partially reversible. There is, however, a clear need for studies based on cellular and molecular methods aimed to clarify the role of factors such as oxidative stress, inflammation and nutritional deficiencies on skeletal muscle structure and function. The focus of this review is to highlight the current knowledge on skeletal muscle dysfunction in COPD and briefly summarize the possible therapeutic implications.