Prediction of peak plantar pressure for diabetic foot: the regressional model.

Background - The increase in peak plantar pressure could be the most important etiological factor for pathogenesis of a diabetic foot. Thus the fate of a diabetic foot syndrome which is a clinical triad of neurological, vascular and musculoskeletal changes could be biomechanically predictive and preventive using clinical parameters. In the presence of peripheral neuropathy, certain clinical parameters could be severely altered resulting into increased peak plantar pressure. Therefore the aim of the study was to identify the most important clinical parameters for the prediction of peak plantar pressure between neuropathy and non-neuropathy type 2 diabetes mellitus participants. Methodology - A total of 380 participants were recruited under the study and divided into two groups (190 each group). The cross-sectional study was conducted at Kasturba Hosipal, Manipal, India. Multiple regression analysis was performed to find the hyperplane of best fit. Stepwise regression was performed with (α entry = 0.15 and α removal = 0.2) to select the best subset of predictors. Results - Adjusted R2 of the final model which included the predictors showed 90.8% variability for the dependent variable. Conclusion - The findings from the regression analysis suggested model was found to be strongly significant in predicting the peak plantar pressure between neuropathy and non-neuropathy type 2 diabetes mellitus participants. Since higher values of peak plantar pressure is strongly associated with risk for future diabetic foot complications, it could be suggested that these clinical parameters could be very useful to assess and should be used in routine clinical practice very effectively. Please note that the running title on the document "A clinical tool for diabetic prediction: the regressional model" differs slightly from the published title

Kinematic and kinetic analysis of maximal velocity deadlifts performed with and without the inclusion of chain resistance.

The purpose of this study was to investigate whether the deadlift could be effectively incorporated with explosive resistance training (ERT) and to investigate whether the inclusion of chains enhanced the suitability of the deadlift for ERT. Twenty-three resistance trained athletes performed the deadlift with 30, 50, and 70% 1-repetition maximum (1RM) loads at submaximal velocity, maximal velocity (MAX), and MAX with the inclusion of 2 chain loads equal to 20 or 40% of the subjects' 1RM. All trials were performed on force platforms with markers attached to the barbell to calculate velocity and acceleration using a motion capture system. Significant increases in force, velocity, power, rate of force development, and length of the acceleration phase (p < 0.05) were obtained when repetition velocity increased from submaximal to maximal. During MAX repetitions with a constant resistance, the mean length of the acceleration phase ranged from 73.2 (±7.2%) to 84.9 (±12.2%) of the overall movement. Compared to using a constant resistance, the inclusion of chains enabled greater force to be maintained to the end of the concentric action and significantly increased peak force and impulse (p < 0.05), while concurrently decreasing velocity, power, and rate of force development (p < 0.05). The effects of chains were influenced by the magnitude of the chain and barbell resistance, with greater increases and decreases in mechanical variables obtained when heavier chain and barbell loads were used. The results of the investigation suggest that the deadlift can be incorporated effectively in ERT programs. Coaches and athletes should be aware that the inclusion of heavy chains may have both positive and negative effects on kinematics and kinetics of an exercise

Head and trunk kinematics and kinetics in normal and cerebral palsy gait: a systematic review.

Background: Cerebral palsy (CP) is a neuromuscular disability characterised by a persistent disorder of movement and posture due to a non-progressive lesion in a developing brain. In children with CP, gait is compromised in a variety of ways. A number of studies have suggested that there is a higher degree of biomechanical variations including kinematics and kinetics at head and trunk while analysing a CP gait. Since coordinated movements of head and trunk are important to analyse a typical gait, it is important to determine these biomechanical changes among children with CP for altered movements such as decreased head and trunk stability. Studies have also reported a variety of outcome measures for clinical use. However, the results among the studies are not consistent as there is variability for altered biomechanics based on type and level of the disorder which requires further investigation. Although clinically very useful, the data regarding the head and trunk biomechanics in children with CP is limited. In this study, a systematic review was done to determine the head and trunk kinematic and kinetics variations in CP gait compared to TD children of the same age-group. Methodology: Scientific articles were obtained by a search in databases including Science Direct, Cinahl, Springer Link, Sport discuss, Web of Science and Pubmed. Limitations used were AND/OR. Full-text articles from 1999 to 2017 in English were selected. Results: A total of 3029 records were identified that included Science Direct (n=1854), Cinahl (n=176), Springer Link (n=121), Sports Discuss (n=101), Web of Science (n=14) and Pubmed (n=763). After removing the duplicates, 1786 records were obtained. Fifty-one full text articles were selected for the eligibility and 27 were included in the study. Conclusions: In this review study, we conclude that children with CP have a significant difference in head and trunk kinetics and kinematics compared to age-matched TD children

A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads.

The purpose of the investigation was to compare the kinematics and kinetics of the deadlift performed with 2 distinct barbells across a range of submaximal loads. Nineteen male powerlifters performed the deadlift with a conventional straight barbell and a hexagonal barbell that allowed the lifter to stand within its frame. Subjects performed trials at maximum speed with loads of 10, 20, 30, 40, 50, 60, 70, and 80% of their predetermined 1- repetition maximum (1RM). Inverse dynamics and spatial tracking of the external resistance were used to quantify kinematic and kinetic variables. Subjects were able to lift a heavier 1RM load in the hexagonal barbell deadlift (HBD) than the straight barbell deadlift (SBD) (265±41 kg vs. 245±39 kg, p < 0.05). The design of the hexagonal barbell significantly altered the resistance moment at the joints analyzed (p < 0.05), resulting in lower peak moments at the lumbar spine, hip, and ankle (p < 0.05) and an increased peak moment at the knee (p < 0.05). Maximum peak power values of 4,388±713 and 4,872±636 W were obtained for the SBD and HBD, respectively (p < 0.05). Across the submaximal loads, significantly greater peak force, peak velocity and peak power values were produced during the HBD compared to during the SBD (p ± 0.05). The results demonstrate that the choice of barbell used to perform the deadlift has a significant effect on a range of kinematic and kinetic variables. The enhanced mechanical stimulus obtained with the hexagonal barbell suggests that in general the HBD is a more effective exercise than the SBD

A biomechanical comparison of the traditional squat, powerlifting squat and box squat.

The purpose of this study was to compare the biomechanics of the traditional squat with two popular exercise variations, commonly referred to as the powerlifting squat and box squat. Twelve male powerlifters performed the exercises with 30, 50 and 70% of their measured 1RM, with instruction to lift the loads as fast as possible. Inverse dynamics and spatial tracking of the external resistance were used to quantify biomechanical variables. A range of significant kinematic and kinetic differences (p < 0.05) emerged between the exercises. The traditional squat was performed with a narrow stance, whereas the powerlifting squat and box squat were performed with similar wide stances (48.3 ± 3.8cm, 89.6 ± 4.9cm, and 92.1 ± 5.1cm, respectively). During the eccentric phase of the traditional squat the knee travelled past the toes resulting in anterior displacement of the system center of mass (COM). In contrast, during the powerlifting squat and box squat a more vertical shin position was maintained, resulting in posterior displacements of the system COM. These differences in linear displacements had a significant effect (p < 0.05) on a number of peak joint moments, with the greatest effects measured at the spine and ankle. For both joints the largest peak moment was produced during the traditional squat, followed by the powerlifting squat, then box squat. Significant differences (p < 0.05) were also noted at the hip joint where the largest moment in all three planes was produced during the powerlifting squat. Coaches and athletes should be aware of the biomechanical differences between the squatting variations and select according to the kinematic and kinetic profile that best match the training goals

Effect of load positioning on the kinematics and kinetics of weighted vertical jumps.

One of the most popular exercises for developing lower-body muscular power is the weighted vertical jump. The present study sought to examine the effect of altering the position of the external load on the kinematics and kinetics of the movement. Twenty-nine resistance-trained rugby union athletes performed maximal-effort jumps with 0, 20, 40 and 60% of their squat 1RM, with the load positioned as follows: 1) on the posterior aspect of the shoulder using a straight barbell (SBJ); and 2) at arms length using a hexagonal barbell (HBJ). Kinematic and kinetic variables were calculated through integration of the vertical ground reaction force data using a forward dynamics approach. Performance of the HBJ resulted in significantly (p < 0.05) greater values for jump height, peak force, peak power and peak rate of force development, compared to the SBJ. Significantly (p < 0.05) greater peak power was produced during the unloaded jump compared to all trials where the external load was positioned on the shoulder. In contrast, significantly (p < 0.05) greater peak power was produced when using the hexagonal barbell combined with a load of 20% 1RM compared to all other conditions investigated. The results suggest that weighted vertical jumps should be performed with the external load positioned at arms length rather than on the shoulder when attempting to improve lower-body muscular performance

Kinetics and kinematics of diabetic foot in type 2 diabetes mellitus with and without peripheral neuropathy: a systematic review and meta-analysis.

Diabetes mellitus patients are at increased risk of developing diabetic foot with peripheral neuropathy, vascular and musculoskeletal complications. Problems develop with a relatively high risk of infection, gangrene and amputation. In addition, altered plantar pressure distribution is an important etiopathogenic risk factor for the development of foot ulcers. The purpose of this systematic review is to understand the biomechanical changes involved through studies of foot kinematic and kinetic in type 2 diabetes mellitus. Scientific articles were identified using electronic databases including Science Direct, CINAHL, Springer Link, Medline, Web of Science, and Pubmed. The selection of articles to include in the systematic review was narrorwed after reading the full text, focusing on studies that used experimental designs relating to the biomechanics of diabetic foot. The meta-analysis report on gait velocity (neuropathy = 128 and non-diabetes = 131) showed that there was a significantly lower gait velocity in neuropathy participants compared to non-diabetes age-matched participants at a high effect level (-0.09, 95% CI -0.13 to 0.05; p < 0.0001). Regarding knee-joint flexion range, there was a significant difference between neuropathy and non-diabetes groups (4.75, 95% CI, -7.53 to 1.97, p = 0.0008). The systematic review found significant differences in kinematic and kinetic variables among diabetic with neuropathy, diabetic without neuropathy and non-diabetic individuals. The review also found that the sample sizes used in some studies were not statistically significant enough contribute reliably to the meta-analysis, so further studies with higher sample sizes are required