David Fewtrell - Academia.edu (original) (raw)

Papers by David Fewtrell

METHOD: The accuracy of CAST in quantifying axial rotation was compared with a goniometer. One su... more METHOD: The accuracy of CAST in quantifying axial rotation was compared with a goniometer. One subject (age 22; mass 80 kg; height 1.8 m) performed 5 isolated forearm rotations of 90°. The subject sat at a table with their forearm resting on it in a fully internally rotated position. This was set as 'zero'. The elbow remained flexed at an

The Foot and Ankle Online Journal

Accurate and reliable joint identification is imperative for the collection of meaningful kinetic... more Accurate and reliable joint identification is imperative for the collection of meaningful kinetic and kinematic data. Of the lower kinetic chain both the hip and knee joints have received a considerable amount of attention in 3D modelling. However, the reliability of methods to define the ankle joint center have received very little attention. This study investigated the reliability of the two marker method (TMM) and the functional ankle method (FAM) on estimating the ankle joint center. Furthermore, the effects of the two-marker method reliability for defining the ankle joint center when the ankle was covered with a brace or protector was investigated. 3D kinematic data was collected from ten participants (8 female and 2 male) whilst walking. The ankle joint center was defined twice using each test condition; TMM (WITHOUT), FAM (FUNCTIONAL), TMM when the ankle was covered with a brace (BRACE), and TMM when the ankle was covered with a protector (PROTECTOR). Intraclass correlations (ICC) were utilised to compare test and retest waveforms and paired samples t-tests were used to compare angular parameters. Significant differences were found in the test-retest angular parameters in the transverse and sagittal planes for the WITHOUT, BRACE, and FUNCTIONAL conditions. The strongest test-retest ICC's were observed in the WITHOUT and PROTECTOR conditions. The findings of the current investigation indicate that there are fewer errors using the TMM when the ankle is uncovered or when covered with soft foam that is easy to palpate through.

Journal of sports sciences, 2014

The current investigation aimed to determine whether there are differences in ball velocity and 3... more The current investigation aimed to determine whether there are differences in ball velocity and 3D kinematics when performing maximal kicks with the dominant and non-dominant limbs. Seventeen male academy soccer players performed maximal speed place kicks with their dominant and the non-dominant limbs. The 3D kinematics of the lower extremities were obtained using a 10-camera motion capture system operating at 500 Hz. Hip, knee and ankle joint kinematics were quantified in the sagittal, coronal and transverse planes and then contrasted using paired t-tests. Significantly higher ball velocities were obtained with the dominant limb. Foot linear velocity and knee extension velocity at ball contact were also found to be significantly greater in the dominant limb. That reduced ball velocities were observed between kicking limbs highlights the potential performance detriments that may occur when kicking with the non-dominant limb; thus, it is recommended that additional bilateral training...

International Journal of Performance Analysis in Sport

Golfers are able to attain a competitive advantage when they are able to achieve long hitting dis... more Golfers are able to attain a competitive advantage when they are able to achieve long hitting distances from the tee. Club-head velocity is perhaps the most commonly reported kinematic variable in the golfing scientific literature. This study aimed to identify 3-D kinematic aspects of the golf swing linked to the generation of club-head velocity using regression analyses. Maximal golf swings were obtained from fifty golfers using an eight camera motion capture system operating at 500 Hz. Full body three-dimensional kinematics were obtained. Multiple regression modelling was used to identify the discrete 3-D kinematic parameters associated with the development of club-head velocity. Two biomechanical parameters; sagittal plane wrist velocity and peak transverse plane torso rotation (Adj R2=0.58, p≤0.01) were obtained as significant predictors of club-head velocity. The findings from this study therefore suggest these parameters are the strongest contributors to ball velocity and pote...

Journal of Athletic Enhancement, 2014

It has been documented that the golf swing should be identical for all clubs, yet biomechanical s... more It has been documented that the golf swing should be identical for all clubs, yet biomechanical studies of the mechanics of the golf swing obtained with different clubs are somewhat lacking. The aim of the current investigation was to determine the three-dimensional kinematic differences in full body swing kinematics when using three different clubs (driver, 9 iron and 6 iron). Thirty five skilled male golfers performed maximal velocity swings using each of the three clubs. Full body 3D kinematics were obtained using an eight camera motion capture system operating at 500 Hz. Differences between clubs were examined using repeated measures ANOVA's and the similarity of the 3D kinematic waveforms were inspected using intraclass correlations. The results showed that the 3D kinematics waveforms from the three clubs generally exhibited a high level of similarity R 2 ≥ 0.861. However, both club head velocity and stance width were significantly greater when using the driver. It was also revealed that the torso, hip and knee were significantly more extended when using the driver. Thus before the notion that the mechanics of the golf swing are similar between clubs can be accepted, additional work is required.

Journal of Sports Sciences, 2004

In this study, we examined the effect of string vibration damping devices on reducing racket fram... more In this study, we examined the effect of string vibration damping devices on reducing racket frame vibration transfer to the forearm. Twenty participants volunteered to hold a tennis racket stationary in a forehand and backhand stroking position while tennis balls were fired at 20 m x s(-1) towards two impact locations, the node of vibration and the dead spot. A three-way analysis of variance with repeated measures on damping condition, impact location and stroke condition was performed on the data. The resonant frequency of the hand-held racket was found to be approximately 120 Hz. No significant differences in amplitude of vibration at the resonant frequency were found for the wrist or the elbow when damped and non-damped impacts were compared. Impacts at the dead spot produced greater amplitudes of vibration (P < 0.01) but no interaction between impact location and string dampers was evident. The string dampers had no effect on the grip force used or the muscle electrical activity in the forearm after impact. In conclusion, we found that string dampers do not reduce the amount of racket frame vibration received at the forearm. We suggest that string dampers remain a popular accessory among tennis players because of their acoustic effects and psychological support rather than any mechanical advantage.

Journal of sports sciences, 2012

The badminton serve requires great skill and may be affected by fatigue. The aim of the present s... more The badminton serve requires great skill and may be affected by fatigue. The aim of the present study was to determine whether carbohydrate ingestion affects badminton performance. Nine male badminton players (age 25 ± 7 years, mass 80.6 ± 8.0 kg) attended the laboratory on three occasions. The first visit involved an incremental exercise test to exhaustion to determine peak heart rate. Participants were given 1 L of a carbohydrate-electrolyte drink or a matched placebo during the experimental trials. The accuracy of 10 long and 10 short serves was determined before and after exercise. The fatiguing exercise was 33 min in duration (83 ± 10% and 84 ± 8% peak heart rate for the placebo and carbohydrate trial respectively). Capillary blood samples (20 μL) were taken before and after exercise for determination of blood glucose and lactate. There was deterioration in long serve accuracy with fatigue (P = 0.002), which carbohydrate ingestion had a tendency to prevent (P = 0.077). There wa...

Journal of Affective Disorders, 2001

Depersonalisation may be part of a symptom-complex, a primary or a secondary disorder. Optimal me... more Depersonalisation may be part of a symptom-complex, a primary or a secondary disorder. Optimal methods of measurement and diagnosis have not been established. We assessed 42 patients with primary or secondary depersonalisation, plus psychiatric and non-psychiatric controls using a variety of self-report questionnaire scales including the Beck depression and anxiety Inventories, and one developed by the authors (the Fewtrell Depersonalisation Scale (FDS)). The correlations between the scales and measures of anxiety and depression were calculated, as were sensitivity and specificity against an operational case definition. All the scales were highly correlated. All could distinguish depersonalisation cases from the rest but none could distinguish between primary and secondary depersonalisation disorder. Anxiety and especially depression were correlated with depersonalisation symptoms. The FDS had high sensitivity (85.7%) and specificity (92.3%) which compared favourably with other instruments. Patients with both derealisation and depersonalisation scored the highest on the FDS. Depersonalisation disorder comprises a measurable cluster of symptoms which may be quantified with the help of self-report scales. Primary and secondary forms overlap, with depressed mood a frequent feature.

Gait & Posture, 2013

Background: During functional wheelchair movement there are several types of stroke pattern that ... more Background: During functional wheelchair movement there are several types of stroke pattern that a manual wheelchair user (MWCU) can utilize in order to propel. Objectives: To examine the biomechanical differences between disabled (WCU) and able-bodied (NWCU) children whilst taking part in functional activities at the Cheetahs Wheelchair Sports Club. Study Design: A multiple measures cohort study. Methods: Eleven participants were divided into two groups; WCU (n = 7) and NWCU (n = 4). All subjects were asked to perform three functional tasks; 30-second agility test, 1-minute distance test and a 10-metre sprint test. Upper body kinematics were recoded using a XSens MVN BIOMECH motion capture suit. Results: NWCU outperformed the WCU in all of the tasks, however, no significant differences between the group's results were found. Nevertheless, significant differences were found in the maximum shoulder flexion angle for both right and left with NWCU utilizing more flexion and near significant differences in the NWCU overall shoulder range for right and left. Conclusions: In order to increase function in young MWCU then more specific-based sessions should be implemented targeting the exploitation of large shoulder ranges during propulsion, consequently resulting in more efficient movement.

European Journal of Sport Science, 2014

Achieving a high ball velocity is important during soccer shooting, as it gives the goalkeeper le... more Achieving a high ball velocity is important during soccer shooting, as it gives the goalkeeper less time to react, thus improving a player's chance of scoring. This study aimed to identify important technical aspects of kicking linked to the generation of ball velocity using regression analyses. Maximal instep kicks were obtained from 22 academy-level soccer players using a 10-camera motion capture system sampling at 500 Hz. Three-dimensional kinematics of the lower extremity segments were obtained. Regression analysis was used to identify the kinematic parameters associated with the development 15 20 of2 ball velocity. A single biomechanical parameter; knee extension velocity of the kicking limb at ball contact Adjusted R = 0.39, p  0.01 was obtained as a significant predictor of ball-velocity. This study suggests that sagittal plane knee extension velocity is the strongest contributor to ball velocity and potentially overall kicking performance. It is conceivable therefore that players may benefit from exposure to coaching and strength techniques geared towards the improvement of knee extension angular velocity as highlighted in this study.