ABSTRACT
Whole-body vibration (WBV) training has been employed alongside conventional exercise like resistance training to enhance skeletal muscle strength and performance. This systematic review examines the evidence regarding the effect of WBV on muscle activity, strength, and performance in healthy individuals. The Academic Search Ultimate, CINAHL, Cochrane CENTRAL, PubMed, ProQuest One Academic and SCOPUS databases were searched from 1990 to April 2023 to retrieve relevant studies. Methodological quality was assessed using the Modified Downs and Black checklist, while the level of evidence was evaluated through the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Even though the quality of the included studies was moderate to high, the level of evidence was very low owing to serious concerns with three or more GRADE domains (risk of bias, inconsistency, indirectness, imprecision, and publication bias) for each outcome of interest across studies. The review suggests that in WBV training, using moderate to high vibration frequencies (25-40 Hz) and high magnitudes (3-6 mm) can enhance muscle activation and strength in pelvis and lower limb muscles. However, findings regarding WBV effect on muscle performance measures were inconsistent. Future research with robust methodology is necessary in this area to validate and support these findings.
Subject(s)
Muscle Strength , Muscle, Skeletal , Vibration , Humans , Healthy Volunteers , Lower Extremity/physiology , Muscle Strength/physiology , Muscle, Skeletal/physiologyABSTRACT
This study investigated the effect of the arm posture and the type of material on the vibration measured at the hands during drilling operation. An experiment was conducted using three different materials (concrete, steel, and wood) and two different arm postures characterized as 90° and 180° angle between the upper arm and forearm. Six male subjects stood on a force platform to measure and control the feed force during the drilling operation. The vibration was measured at the interface between the drill and both hands. The results showed that the effect of arm posture was dependent on the type of material being drilled. For example, drilling in concrete yielded higher frequency-weighted acceleration with the 90° arm posture than the 180° posture while drilling in wood showed an opposite trend. The results tend to suggest no correlation between the material hardness and the vibration at the hands. Higher vibration was also observed at the right hand than the left hand. It is recommended to not use the vibration emission data reported by manufacturers of power tools to evaluate incidences of hand-arm vibration syndrome (HAVS) but to rely on real measurements taken in the field under typical operating conditions.
Subject(s)
Hand , Vibration , Humans , Male , Posture , ForearmABSTRACT
In recent years, whole-body vibration (WBV) training has received an increasing interest in the sports and medical fields. However, there has been inconsistency among several studies regarding the effect of WBV training on the human body, which is partly due to the lack of the existence of guidelines for using WBV training machines. To understand the effect of WBV training on the human body and build the needed regulations, it is essential first to understand the biodynamic responses to vibration which represent how vibration is transmitted to and through the human body. The purpose of this study is to systematically review previous studies that measured biodynamic responses when using WBV training machines to highlight inconsistencies in their results and provide possible reasons for them. An extensive literature search was performed on the SCOPUS database to obtain relevant studies. One hundred and fifty-six potentially relevant studies were obtained but after further screening, 23 papers from 2007 to 2020 met inclusion criteria and were included in the study. The papers were analysed with respect to acceleration, transmissibility, interface force, and apparent mass during different vibration settings, body posture, age, and sex. Results and conflicts among studies were highlighted and possible explanations for the inconsistency were provided.
