A protocol for a new methodological model for work-related shoulder complex injuries:From diagnosis to rehabilitation

Incluye 4 ficheros de datosBackground: Work-related injuries of the shoulder complex represent a challenge for clinicians because of the large variety of clinical entities involved and the broad anatomic structures that can be affected. Furthermore, commonly performed orthopedic tests have demonstrated limited accuracy for diagnosing the injury despite considerable research efforts. The aim of this study protocol is therefore to describe a comprehensive approach integrating both a clinical- and functional status-based pathology and an adapted rehabilitation prescription. Methods/Design: A longitudinal cohort study will be performed at the Department of Rehabilitation and Medical Assistance of a mutual insurance society for work-related injury management in Spain (Mutua Navarra, Pamplona, Navarra Spain). Patients will be attended by an occupational physician who specializes in work-related injuries and is part of the project team that will systematically visit all the participants. After the medical diagnosis and any requested supplementary evaluations (i.e., radiological examinations), the patients will be referred to the rehabilitation service. Before the physiotherapeutic rehabilitation program is initiated, the patients will undergo a comprehensive functional screening at the biomechanics laboratory. Using a decision-making scheme, the identified functional deficits will be used to customize the individual rehabilitation plan. Discussion: The proposed objective criteria-based shoulder diagnosis and rehabilitation model could be a new effective strategy for minimizing the time required to regain functional capacity and recover from symptoms among patients with work-related shoulder injuries

Anaerobic Energy Expenditure and Mechanical Efficiency during Exhaustive Leg Press Exercise

Information about anaerobic energy production and mechanical efficiency that occurs over time during short-lasting maximal exercise is scarce and controversial. Bilateral leg press is an interesting muscle contraction model to estimate anaerobic energy production and mechanical efficiency during maximal exercise because it largely differs from the models used until now. This study examined the changes in muscle metabolite concentration and power output production during the first and the second half of a set of 10 repetitions to failure (10RM) of bilateral leg press exercise. On two separate days, muscle biopsies were obtained from vastus lateralis prior and immediately after a set of 5 or a set of 10 repetitions. During the second set of 5 repetitions, mean power production decreased by 19% and the average ATP utilisation accounted for by phosphagen decreased from 54% to 19%, whereas ATP utilisation from anaerobic glycolysis increased from 46 to 81%. Changes in contraction time and power output were correlated to the changes in muscle Phosphocreatine (PCr; r = −0.76; P<0.01) and lactate (r = −0.91; P<0.01), respectively, and were accompanied by parallel decreases (P<0.01-0.05) in muscle energy charge (0.6%), muscle ATP/ADP (8%) and ATP/AMP (19%) ratios, as well as by increases in ADP content (7%). The estimated average rate of ATP utilisation from anaerobic sources during the final 5 repetitions fell to 83% whereas total anaerobic ATP production increased by 9% due to a 30% longer average duration of exercise (18.4±4.0 vs 14.2±2.1 s). These data indicate that during a set of 10RM of bilateral leg press exercise there is a decrease in power output which is associated with a decrease in the contribution of PCr and/or an increase in muscle lactate. The higher energy cost per repetition during the second 5 repetitions is suggestive of decreased mechanical efficiency

Additional file 3: of A protocol for a new methodological model for work-related shoulder complex injuries: From diagnosis to rehabilitation

(Red). Examples of exercises to improve strength deficits. The complexity of the exercises increases from (a) to (c). Progression is made in order to isolate different rotator cuff muscles isolated (a, b) or in combination to the scapular retractors (c). (TIF 689 kb

Increased PIO2 at exhaustion in hypoxia enhances muscle activation and swiftly relieves fatigue: a placebo or a PIO2 dependent effect?

To determine the level of hypoxia from which muscle activation (MA) is reduced during incremental exercise to exhaustion (IE), and the role played by PIO2 in this process, ten volunteers (21±2 years) performed four IE in severe acute hypoxia (SAH) (PIO2=73 mmHg). Upon exhaustion, subjects were asked to continue exercising while the breathing gas mixture was swiftly changed to a placebo (73 mmHg) or to a higher PIO2 (82, 92, 99, 142 mmHg), and the IE continued until a new exhaustion. At the second exhaustion, the breathing gas was changed to room air (normoxia) and the IE continued until the final exhaustion. MA, as reflected by the vastus medialis (VM) and lateralis (VL) EMG raw and normalized root mean square (RMSraw, RMSNz, respectively), normalized total activation index (TAINz), and burst duration were 8-20 % lower at exhaustion in SAH than in normoxia (P<0.05). The switch to a placebo or higher PIO2 allowed for the continuation of exercise in all instances. RMSraw, RMSNz and TAINz were increased by 5-11% when the PIO2 was raised from 73 to 92 or 99 mmHg, and VL and VM averaged RMSraw by 7% when the PIO2 was elevated from 73 to 142 mmHg (P<0.05). The increase of VM-VL average RMSraw was linearly related to the increase in PIO2, during the transition from SAH to higher PIO2 (R2=0.99, P<0.5). In conclusion, increased PIO2 at exhaustion reduces fatigue and allows for the continuation of exercise in moderate and SAH, regardless of the effects of PIO2 on MA. At task failure, MA is increased during the first 10 s of increased PIO2 when the IE is performed at a PIO2 close to 73 mmHg and the PIO2 is increased to 92 mmHg or higher. Overall, these findings indicate that one of the central mechanisms by which severe hypoxia may cause central fatigue and task failure is by reducing the capacity for reaching the appropriate level of muscle activation to sustain the task. The fact that at exhaustion in severe hypoxia the exercise was continued with the placebo-gas mixture demonstrates that this central mechanism has a cognitive component

Additional file 3: of A protocol for a new methodological model for work-related shoulder complex injuries: From diagnosis to rehabilitation

(Red). Examples of exercises to improve strength deficits. The complexity of the exercises increases from (a) to (c). Progression is made in order to isolate different rotator cuff muscles isolated (a, b) or in combination to the scapular retractors (c). (TIF 689Â kb

Additional file 2: of A protocol for a new methodological model for work-related shoulder complex injuries: From diagnosis to rehabilitation

(Pink). Examples of internal rotation deficit exercises. The complexity of the exercises increases from (a) to (c). The patient imposes different stretching intensities to the shoulder posterior capsule depending on his/her tolerance. (TIF 563Â kb

Additional file 1: of A protocol for a new methodological model for work-related shoulder complex injuries: From diagnosis to rehabilitation

(Blue). Example of scapulothoracic instability exercises. The complexity of the exercises increases from a to b. The patient must control scapular retraction (a) and co-contraction from scapular retractor and protractors (b). (TIF 482Â kb

A protocol for a new methodological model for work-related shoulder complex injuries: From diagnosis to rehabilitation

Abstract Background Work-related injuries of the shoulder complex represent a challenge for clinicians because of the large variety of clinical entities involved and the broad anatomic structures that can be affected. Furthermore, commonly performed orthopedic tests have demonstrated limited accuracy for diagnosing the injury despite considerable research efforts. The aim of this study protocol is therefore to describe a comprehensive approach integrating both a clinical- and functional status-based pathology and an adapted rehabilitation prescription. Methods/Design A longitudinal cohort study will be performed at the Department of Rehabilitation and Medical Assistance of a mutual insurance society for work-related injury management in Spain (Mutua Navarra, Pamplona, Navarra Spain). Patients will be attended by an occupational physician who specializes in work-related injuries and is part of the project team that will systematically visit all the participants. After the medical diagnosis and any requested supplementary evaluations (i.e., radiological examinations), the patients will be referred to the rehabilitation service. Before the physiotherapeutic rehabilitation program is initiated, the patients will undergo a comprehensive functional screening at the biomechanics laboratory. Using a decision-making scheme, the identified functional deficits will be used to customize the individual rehabilitation plan. Discussion The proposed objective criteria-based shoulder diagnosis and rehabilitation model could be a new effective strategy for minimizing the time required to regain functional capacity and recover from symptoms among patients with work-related shoulder injuries. Trial registration The study protocol has been registered on Clinical Trials.gov as NCT02732002 (April 10th 2016)