Introduction. Dentists and hygienists are strongly affected by musculoskeletal disorders (MSDs). As workstation concepts are supported by subjective arguments only, the aim of this study was to use objective measurements to compare the variability of strain in various concepts: a dental chair equipped with a cart or an over-the-patient delivery system without an assistant, and Dr Daryl Beach’s concept with an assistant. Methods. Goniometric and electromyographic recordings were made on 8 subjects, during a scaling operation. The electrical activity of their trapezius and lumbar muscles was compared, as were their cervical and lumbar ranges of motion. Results. The results showed that there was a wide variability depending on the workstation. However, the Beach concept tended to reduce physical strain on most parameters: duration of left lumbar muscle activity (2% compared to 15% of time spent in >10% maximal voluntary contraction, MVC), time spent in cervical side bending (4% compared to 30%), cervical flexion of >20° (9% compared to 40%), and left trapezius activity (9% of time spent >10% MVC compared to 28%). Conclusion. Practitioners and students should adjust their workstations to reduce the prevalence of MSDs.
Purpose: Footwear and equipment worn by military personnel is of importance for them to be able to meet the physical demands specific to their profession daily activities. Aim of the present study was to investigate by means of gait analysis how army-provided footwear and equipment influence the range of motion of hip, knee and ankle joints as well as stride length.Methods: Thirty-two soldiers were subjected to gait analysis on a treadmill by way of video recordings and goniometric measurements. Results: The stride length increased when military shoes are worn. We found no influence on stride length in connection to increased loading. The weight of the shoes represents the decisive factor. Neither shoes nor equipment changed the range of motion of the knee joint.Weight of equipment affected range of motion of the hip joint. The range of motion of the upper and lower ankle joints was mainly influenced by the properties of the shoes. Conclusions: Military footwear and weight of equipment influence stride length and range of motion of joints of the lower extremities in a specific way. Shape of material is the decisive factor.
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