Leo Ng

Self-reported prevalence, pain intensity and risk factors of low back pain in adolescent rowers.

OBJECTIVES The primary objective of this study was to determine the lifetime and point prevalence of low back pain, the related pain intensity and the rowing-related aggravating factors for low back pain in adolescent rowers who participated in school-level competitions. The secondary objective was to determine whether between-gender differences existed in these data. DESIGN Retrospective cross-sectional survey METHODS 130 adolescent male and 235 adolescent female rowers aged between 14 and 16 years were recruited in this study. Participants completed a questionnaire to determine their lifetime and point prevalence of low back pain, their pain intensity and rowing-related factors that aggravated their low back pain. RESULTS A high lifetime and point prevalence of low back pain were found in both adolescent male (93.8% and 64.6%, respectively) and female (77.9% and 52.8%, respectively) rowers. A significant between-gender difference was reported for both statistics (p<0.001). A significantly lower (p=0.003) level of pain intensity via a visual analog scale was found for males (4.1/10) when compared to females (5.0/10). Similar rowing-related aggravating factors were reported by males and females although fewer males reported that lifting the rowing shell aggravated their low back pain. CONCLUSIONS A high lifetime and point prevalence of low back pain was reported by the adolescent rowers recruited in this study. While a greater proportion of adolescent male rowers reported low back pain, they reported a lower intensity of pain when compared to their female counterparts. Coaches, clinicians and rowers should be made aware of these findings such that future research and development can focus on promoting pain management strategies in this sport.

Caution: The use of an electromagnetic device to measure trunk kinematics on rowing ergometers

The aim of the study was to determine the accuracy and variability of an electromagnetic device in measuring spinal kinematics on a traditional and replica rowing ergometer. Kinematic data collected from the 3-Space FastrakTM system using a Standard Concept II ergometer were compared with a replica ergometer that was in part, composed of non-ferrous materials (modified ergometer). The Fastraks sensors were fixed to a wooden “spine” with known angles (as measured by an inclinometer). The mean inclinometer angle from four sensors (1 ± 0.2°) was significantly different than the mean angle recorded on the standard ergometer ( − 5.4 ± 3.4°) (p = 0.007) whilst the angles recorded on the modified ergometer (1.4 ± 0.8°) were statistically equivalent to the inclinometer recordings (p = 0.660). These results indicate that the presence of ferrous material in a standard ergometer reduced the accuracy and increased the variability of data collected with the electromagnetic device. However, information collected on largely non-ferrous ergometers can provide coaches, biomechanists and clinicians with a quick and effective way to measure trunk kinematics during ergometer rowing.

The effect of ankle bracing on knee kinetics and kinematics during volleyball-specific tasks

The purpose of this study was to examine the effects of ankle bracing on knee kinetics and kinematics during volleyball tasks. Fifteen healthy, elite, female volleyball players performed a series of straight‐line and lateral volleyball tasks with no brace and when wearing an ankle brace. A 14‐camera Vicon motion analysis system and AMTI force plate were used to capture the kinetic and kinematic data. Knee range of motion, peak knee anterior–posterior and medial–lateral shear forces, and peak ground reaction forces that occurred between initial contact with the force plate and toe off were compared using paired sample t‐tests between the braced and non‐braced conditions (P < 0.05). The results revealed no significant effect of bracing on knee kinematics or ground reaction forces during any task or on knee kinetics during the straight‐line movement volleyball tasks. However, ankle bracing was demonstrated to reduce knee lateral shear forces during all of the lateral movement volleyball tasks. Wearing the Active Ankle T2 brace will not impact knee joint range of motion and may in fact reduce shear loading to the knee joint in volleyball players.

Effects of two different knee tape procedures on lower-limb kinematics and kinetics in recreational runners

The purpose of this study was to compare the effects of Mulligans tape (MT) and kinesio tape (KT) with no tape (NT) on hip and knee kinematics and kinetics during running. Twenty‐nine female recreational runners performed a series of ‘run‐throughs’ along a 10‐m runway under the three taping conditions. Two force plates and a 14‐camera Vicon motion analysis system (Oxford Metrics, Inc., Oxford, UK) captured kinematic and kinetic data for each dependent variable from ground contact to toe off. Comparisons of each dependent variable under three taping conditions were assessed through Statistical Package for the Social Sciences (SPSS; SPSS, Inc., Chicago, Illinois, USA; P‐value < 0.01) using repeated measure analyses of variance. For each dependent variable with a P‐value < 0.01, repeated measures with pairwise comparisons and Bonferroni adjustment were conducted to compare the three taping conditions. MT induced a significant reduction in anterior and posterior hip forces, knee flexion angular velocity, knee extensor moments, and hip flexion and extension moments compared with NT and KT (P = 0.001). There was no difference in hip or knee, kinematics or kinetics, between KT and NT (P = 1.000). MT appears to influence hip and knee biomechanics during running in an asymptomatic sample, whereas KT appeared to be biomechanically not different from NT.

Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower‐limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligans tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain‐free 12–15‐year‐old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower‐limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.

The Relationship Between Landing Sound, Vertical Ground Reaction Force, and Kinematics of the Lower Limb During Drop Landings in Healthy Men

STUDY DESIGN Controlled laboratory study, cross-sectional. BACKGROUND Soft-landing instruction, which is advocated in several injury prevention programs, is thought to have a qualitative relationship with decreased vertical ground reaction forces (vGRFs) and increased lower-limb joint excursions. OBJECTIVE To quantify the relationships among landing sound, vGRFs, and lower-limb kinematics during a drop-landing task. METHODS Twenty-six asymptomatic men aged 18 to 35 years were asked to perform 15 single-leg drop landings from a 30-cm height. Five trials were collected under 3 sound conditions: normal, quiet, and loud. The vGRF, lower-limb kinematics (sagittal plane), and impact sound were recorded during the deceleration phase. RESULTS A simple linear regression revealed a significant relationship between landing sound and vGRF (R(2) = 0.42, P<.001). A repeated-measures analysis of variance showed that ankle and knee excursion significantly increased by 7.0° and 11.7°, respectively, during quiet landing (compared to normal landing; P<.001). During the loud landing condition, ankle joint excursion significantly decreased by 9.4° compared to the normal landing condition (P<.001), and hip joint excursion significantly increased by 4.0° compared to normal landing condition (P<.045). CONCLUSION As landing sound decreases, so does vGRF during a drop-landing task. These reductions were achieved by increasing ankle and knee joint excursions. Conversely, as the landing sound increases, so does vGRF. This was the result of decreasing ankle joint excursion and increasing hip joint excursion.

Cognitive Functional Therapy for the Management of Low Back Pain in an Adolescent Male Rower: A Case Report

STUDY DESIGN Case report. BACKGROUND Contemporary low back pain models propose that the experience of and responses to pain result from a complex interaction of biopsychosocial factors. This supports the need for a management approach that addresses the biological, psychological, and social components that may be related to the pain disorder. This case report demonstrates the application of, and outcomes associated with, a cognitive functional intervention that considers neurophysiological, physical, psychosocial, cognitive, and lifestyle dimensions for the management of a rower with nonspecific chronic low back pain. CASE DESCRIPTION An adolescent male club-level rower with nonspecific chronic low back pain was classified as having a motor control impairment with a lower lumbar compressive-loading pattern in flexion. Evaluation of this patient included ergometer rowing analysis (clinical and laboratory) before and after an 8-week intervention, and outcome measures at a 12-week follow-up. The intervention consisted of a cognitive functional approach that targeted optimization of movement behavior, providing the rower with alternative movement strategies to minimize sustained flexion loading. OUTCOMES Reduced temporal summation of pain while ergometer rowing and reduced functional disability were observed preintervention to 12 weeks postintervention by changes in Roland-Morris Disability Questionnaire score (12/24 to 1/24) and the Patient-Specific Functional Scale (4/30 to 26/30), and associated improvements in lower-limb and back muscle endurance and changes in hip and spinopelvic kinematics during ergometer rowing. In particular, there was a greater use of available range of movement in the lumbar spine postintervention. DISCUSSION The cognitive functional intervention for this patient resulted in reduced pain and functional disability related to ergometer rowing, which was associated with a change in lumbar kinematics and improved lower-limb and back muscle endurance. The results suggest that providing the rower with greater use of his available range of movement may enhance load distribution during the drive phase of rowing. Registered at Australian New Zealand Clinical Trials Registry (ACTRN12609000565246). LEVEL OF EVIDENCE Therapy, level 4.

Spinal Kinematics of Adolescent Male Rowers with Back Pain in Comparison with Matched Controls During Ergometer Rowing

There is a high prevalence of low back pain (LBP) in adolescent male rowers. In this study, regional lumbar spinal kinematics and self-reported LBP intensity were compared between 10 adolescent rowers with moderate levels of LBP relating to rowing with 10 reporting no history of LBP during a 15-minute ergometer trial using an electromagnetic tracking system. Adolescent male rowers with LBP reported increasing pain intensity during ergometer rowing. No significant differences were detected in mean upper or lower lumbar angles between rowers with and without LBP. However, compared with rowers without pain, rowers with pain: (1) had relatively less excursion of the upper lumbar spine into extension over the drive phase, (2) had relatively less excursion of the lower lumbar spine into extension over time, (3) had greater variability in upper and lower lumbar angles over the 15-minute ergometer trial, (4) positioned their upper lumbar spine closer to end range flexion for a greater proportion of the drive phase, and (5) showed increased time in sustained flexion loading in the upper lumbar spine. Differences in regional lumbar kinematics exist between adolescent male rowers with and without LBP, which may have injury implication and intervention strategies.

Effect of External Ankle Support on Ankle and Knee Biomechanics During the Cutting Maneuver in Basketball Players

Background: Despite the high prevalence of lower extremity injuries in female basketball players as well as a high proportion of athletes who wear ankle braces, there is a paucity of research pertaining to the effects of ankle bracing on ankle and knee biomechanics during basketball-specific tasks. Purpose: To compare the effects of a lace-up brace (ASO), a hinged brace (Active T2), and no ankle bracing (control) on ankle and knee joint kinematics and joint reaction forces in female basketball athletes during a cutting maneuver. Study Design: Controlled laboratory study. Methods: Twenty healthy, semi-elite female basketball players performed a cutting task under both ankle brace conditions (lace-up ankle brace and hinged ankle brace) and a no-brace condition. The 3-dimensional kinematics of the ankle and knee during the cutting maneuver were measured with an 18-camera motion analysis system (250 Hz), and ground-reaction force data were collected by use of a multichannel force plate (2000 Hz) to quantify ankle and knee joint reaction forces. Conditions were randomized using a block randomization method. Results: Compared with the control condition, the hinged ankle brace significantly restricted peak ankle inversion (mean difference, 1.7°; P = .023). No significant difference was found between the lace-up brace and the control condition (P = .865). Compared with the lace-up brace, the hinged brace significantly reduced ankle and knee joint compressive forces at the time of peak ankle dorsiflexion (mean difference, 1.5 N/kg [P = .018] and 1.4 N/kg [P = .013], respectively). Additionally, the hinged ankle brace significantly reduced knee anterior shear forces compared with the lace-up brace both during the deceleration phase and at peak ankle dorsiflexion (mean difference, 0.8 N/kg [P = .018] and 0.9 N/kg [P = .011], respectively). Conclusion: The hinged ankle brace significantly reduced ankle inversion compared with the no-brace condition and reduced ankle and knee joint forces compared with the lace-up brace in a female basketball population during a cutting task. Compared with the lace-up brace, the hinged brace may be a better choice of prophylactic ankle support for female basketball players from a biomechanical perspective. However, both braces increased knee internal rotation and knee abduction angles, which may be problematic for a population that already has a high prevalence of knee injuries.

The prevalence and severity of injuries in field hockey drag flickers: a retrospective cross-sectional study

ABSTRACT The drag flick is the preferred method of scoring during a penalty corner in field hockey. Performing the drag flick requires a combination of strength, coordination and timing, which may increase susceptibility to injuries. However, injury prevalence in drag flickers has not previously been investigated. Therefore, this study compared the injury prevalence and severity of lower limb and lower back injuries between drag flickers and non-drag flickers in field hockey. A total of 432 local, national and international adult field hockey players (242 males, 188 females) completed an online questionnaire to retrospectively determine the 3-month prevalence and severity of ankle, knee, hip and lower back injuries. Of this group, 140 self-identified as drag flickers and 292 as non-drag flickers. The results showed that drag flickers had significantly higher prevalence of hip (OR: 1.541; 95% CI: 1.014, 2.343) and lower back injury (OR: 1.564; 95% CI: 1.034, 2.365) compared to non-drag flickers. No significant differences were observed between drag flickers and non-drag flickers in injury prevalence at the ankle and knee. There were no significant between-group differences in injury severity scores. Overall, the prevalence of hip and lower back injuries was significantly higher in drag flickers compared to non-drag flickers.