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D Hopper

Publications and source records attributed to D Hopper.

13 recordsLinked to original sources
PubMed2006

Dance training intensity at 11-14 years is associated with femoral torsion in classical ballet dancers.

OBJECTIVE: To examine in a cross sectional study the influence of femoral torsion (FT) and passive hip external rotation (PER) on turnout (TO). Starting age, years of classical ballet training, and current and past dance training intensity were assessed to determine their influence on FT, PER, and TO in pre-professional female dancers. METHODS: Sixty four dancers (mean (SD) age 18.16 (1.80) years) were recruited from four different dance training programmes. They completed a dance history questionnaire. FT was measured using a clinical method. PER was measured with the subjects prone, and TO was measured with the subjects standing. RESULTS: Mean TO was 136 degrees, mean unilateral PER was 49.4 degrees, and mean FT was 18.4 degrees. A positive correlation was observed between PER combined (PERC) and TO (r = 0.443, p < 0.001). A negative association was found between FT combined (FTC) and PERC (r = -0.402, p = 0.001). No association was found between starting age or years of classical ballet training and FTC, PERC, or TO. Dancers who trained for six hours a week or more during the 11-14 year age range had less FT than those who trained less (mean difference 6 degrees, 95% confidence interval 1.4 to 10.3). Students currently training for longer had higher levels of TO (p < 0.001) but comparable PERC and FTC. CONCLUSION: FT is significantly associated with PERC. Dancers who trained for six hours a week or more at 11-14 years of age had significantly less FT. FTC had a significant influence on PERC, but no influence on the execution of TO.

Adolescent↗
PubMed2005

Dynamic soft tissue mobilisation increases hamstring flexibility in healthy male subjects.

OBJECTIVES: The purpose of this study was to investigate the effect of dynamic soft tissue mobilisation (STM) on hamstring flexibility in healthy male subjects. METHODS: Forty five males volunteered to participate in a randomised, controlled single blind design study. Volunteers were randomised to either control, classic STM, or dynamic STM intervention. The control group was positioned prone for 5 min. The classic STM group received standard STM techniques performed in a neutral prone position for 5 min. The dynamic STM group received all elements of classic STM followed by distal to proximal longitudinal strokes performed during passive, active, and eccentric loading of the hamstring. Only specific areas of tissue tightness were treated during the dynamic phase. Hamstring flexibility was quantified as hip flexion angle (HFA) which was the difference between the total range of straight leg raise and the range of pelvic rotation. Pre- and post-testing was conducted for the subjects in each group. A one-way ANCOVA followed by pairwise post-hoc comparisons was used to determine whether change in HFA differed between groups. The alpha level was set at 0.05. RESULTS: Increase in hamstring flexibility was significantly greater in the dynamic STM group than either the control or classic STM groups with mean (standard deviation) increase in degrees in the HFA measures of 4.7 (4.8), -0.04 (4.8), and 1.3 (3.8), respectively. CONCLUSIONS: Dynamic soft tissue mobilisation (STM) significantly increased hamstring flexibility in healthy male subjects.

Adolescent↗
PubMed2004

An evaluation of differences in hip external rotation strength and range of motion between female dancers and non-dancers.

OBJECTIVES: To evaluate the differences in hip external rotation (ER) strength and inner, outer, and total hip ER range of motion (ROM) between dancers and non-dancers and between left and right sides in each group. METHODS: Seventy one subjects (34 dancers and 37 non-dancers) volunteered for this study. The strength (truncated range average torque (TRAT), work, and angle specific torque (AST)) of the hip external rotator muscle group, through the full available active hip ER ROM, was evaluated using concentric isokinetic (30 degrees /s) testing on a KinCom dynamometer. Adjustment for lean body mass (LBM) was made for comparison of strength between groups. A two way repeated analysis of covariance was used to compare strength between groups. A two way repeated analysis of variance was used to compare strength between sides and ROM between groups and sides. Bonferroni correction was made for multiple analyses, and significance was accepted at p<or=0.05. RESULTS: AST at 0 degrees , 20 degrees , 30 degrees , and 40 degrees of hip ER was greater in the dancers than the non-dancers (p<or=0.022). TRAT, work, AST(0 degrees ), AST(20 degrees ), and AST(30 degrees ) of hip ER were all greater on the right side than the left (p = 0.007) in both groups. Dancers had greater inner ER ROM (p = 0.013) and less outer ER ROM than non-dancers (p<or=0.001). There was no difference in total ER ROM between groups (p = 0.133). The right side had greater inner ER (p<or=0.001) and total ER ROM (p<or=0.001) than the left in both groups. CONCLUSIONS: Ballet dancers have greater inner range, angle specific strength and inner range ER ROM, demonstrated by a shift in the dancers' strength curves. This shift in the strength curve towards the inner range of hip ER may be an adaptive training response.

Adolescent↗
PubMed2000

Quantitative telomerase expression in glioblastomas shows regional variation and down-regulation with therapy but no correlation with patient outcome.

Despite the nearly ubiquitous expression of telomerase in almost all types of malignant human tumors, studies have shown widely varying positivity in the highest-grade glioma, the glioblastomas (GBMs), ranging from 26% to 100% of tumors analyzed. We have previously shown significant variability in positive versus negative telomerase expression from region to region within the same GBM. In this study, we hypothesized that application of new quantitative methodology would extend our previous observations and identify whether there is heterogeneity in levels of protein expression even within areas positive for telomerase in high-grade gliomas. Finally, we sought to correlate quantitative telomerase expression with patient outcome and therapeutic response. Quantitative analysis was achieved by polymerase chain-based TRAP assay with phosphorimager analysis and compared with clinical information obtained from 19 patients, most with primary, untreated GBMs. Results showed up to 3-fold variability in telomerase levels across multiple regional samples from the same patient, as well as between patients. In 5 of 6 patients with recurrent tumors who had received intervening radiation therapy or chemotherapy, telomerase was downregulated in the second, post-therapy sample. These data provide in vivo corroboration of recent in vitro experiments showing telomerase downregulation after radiation therapy or chemotherapy treatment of cell lines. Our finding of variability in levels of telomerase expression in GBMs parallels the known heterogeneity of these tumors for histologic features and cell growth-related factors. Statistical analysis showed no relationship between TRAP score and either time to clinical progression or time to death.

Adult↗
PubMed2000

Peroneal latency in normal and injured ankles at varying angles of perturbation.

The aim of this study was to determine whether there was a difference in latency of the peroneus longus muscle at varying amplitudes of ankle inversion perturbation and between individuals with and without a history of ankle injury. Thirty-four male athletes from different football codes (soccer, rugby) received four random tilts to their left ankles at 5 degrees, 10 degrees, and 15 degrees in the frontal plane on a dual platform trap door. Peroneal latency was defined as the time difference between onset of the trap door movement, as detected by an accelerometer, and the onset of muscle activation above a resting baseline, as recorded using surface electromyography. Latency was determined using an algorithm. A series of repeated measures analyses of variance indicated that the latency was reliable between trials. There was no statistical evidence that history of injury or subjective ankle instability influenced the latency; however, there was a systematic difference between dominant and nondominant legs (dominant, 6.3 ms faster), and there was a small systematic effect (3 ms) for the angle of inversion perturbation. Muscle latency responses in male football players are thought to be influenced more by dominance than by history of injury or amplitude of perturbation.

Adolescent↗
PubMed1998

Reliability of the peroneal latency in normal ankles.

The aim of this study was to determine the reliability of peroneal latency between trials and to compare the right and left sides in healthy subjects. A dual platform trapdoor was constructed to tilt the right or the left ankle by 30 degrees in the frontal plane. Electromyography recorded the onset of peroneal activity in response to this perturbation, and an accelerometer detected the onset of trapdoor movement. Peroneal latency was determined algorithmically as the time difference between the onset of trapdoor movement and the onset of peroneal activity. Twenty trials were recorded from 31 right leg dominant, healthy subjects. Peroneal latency was measured successfully for 613 trials (99% success rate). A repeated measures analysis of variance showed a main effect for side with the right, dominant side recording a longer latency. Intertrial reliability of the peroneal latency was high (intraclass correlation coefficients for the right and left legs were .91 and .82, respectively). Thus, peroneal latency is a reliable measure of the polysynaptic reflex ares involved in the response of these muscles to a sudden inversion stress.

Adult↗
PubMed1997

Does ice immersion influence ankle joint position sense?

The purpose of this study was to determine whether a fifteen minute ice immersion treatment influenced the normal ankle joint position sense at 40% and 80% range of inversion and to establish the length of treatment effect through monitoring the rewarming process. Forty nine healthy volunteers between the ages of 17 and 28 were tested. Subjects were screened to exclude those with a history of ankle injuries. The subject's skin temperature over antero-lateral aspect of the ankle was measured using a thermocouple device during the fifteen minutes ice intervention and thirty minutes post-intervention. Testing of ankle joint position sense using the pedal goniometer was performed before and after a clinical application of ice immersion. The testing required the subject to actively reposition their ankle at 40% and 80% of their total range of inversion. The majority of subjects experienced numbness of the foot and ankle by the fifth or sixth minute during ice immersion. One minute after immersion skin temperatures averaged 15 degrees C + 1.7 degrees C. Skin temperature was seen to rise relatively rapidly for the first ten minutes and then slowed considerably. Subjects had not returned to the pre-test skin temperatures by thirty minutes. A significant difference in ankle joint position sense (p < 0.0499) following fifteen minutes of ice immersion was found. However, the magnitude of this difference (0.5 degree) would not be deemed significant in clinical practice. The research found no significant difference in joint position sense between 40% and 80% of the range of inversion both before and after cryotherapy. These findings suggest that the clinical application of cryotherapy is not deleterious to joint position sense and assuming normal joint integrity patients may resume exercise without increased risk of injury.

Adult↗
PubMed1995

A descriptive epidemiology of netball injuries during competition: a five year study.

OBJECTIVE: To investigate the relation between injury profiles - including assessment, treatment, severity, and the perceived reason for the injury - and participation in competitive netball. METHODS: Between 1985 and 1989, approximately 11,228 netball players participated in a 14 week netball competition held at the major competitive centre in Western Australia; 608 netball players presented to the first aid room with an injury and were assessed and treated by the same physiotherapist and St John First Aid officer. RESULTS: The overall incidence rate during competition was 5.4%, with more injuries occurring in the A grade level of play. Ankle injuries (84%) were most frequent, with 67% of these injuries diagnosed as lateral ligament sprains while a further 10% of players who suffered this classification of injury sustained a fracture to the ankle or foot. Few injuries occurred at the knee joint (8.3%) and only 1.8% of these injuries were diagnosed as an injury to the anterior cruciate ligament. The direct probability of a netball players' risk estimate was 0.054 per person per match which implied that netball was a relatively safe game. Injuries sustained during practice were not included in this study. CONCLUSIONS: Netball is a relatively safe game though the potential for injury increases with the level of competition.

Adolescent↗
PubMed1994

Foot types and lower limb injuries in elite netball players.

In assessing the foot types and lower limb injuries of elite netball players, the following summary seems warranted. Ninety percent of elite female netball players had symmetrical foot types for both feet and these players had experienced at least one lower limb injury. Only 7.6% players (N = 16) of the 204 players surveyed had never sustained a lower limb injury during their netball careers. Regardless of foot type, the injury history of these elite netball players presented with a total number of 449 injuries that occurred to both ankle joints (36%), one ankle joint (16%), both knee joints (6%), one knee joint (13%), shin soreness (18%), and retropatellar pain problems (11%). On further inspection, 55% of players experienced one to two lower limb injuries throughout their netball careers. Injured players showed that players with the pronating foot types with rearfoot abnormalities (57%) were the most commonly injured and that compensated rearfoot varus foot type presented the most lower limb injuries for all body sites.

Adolescent↗
PubMed1993

Lower limb and back injury patterns of elite netball players.

The purpose of this study was to investigate the relationships between lower limb and back injuries with perceived landing patterns and podiatric variables for injured and uninjured elite netball players. 228 players of a possible 240 participants at the 1988 Australian netball championships completed injury questionnaires and were assessed for injury status. Approximately 92% of those who were part of the injury surveys were also given a podiatric assessment. Pearson chi 2 and unpaired t-tests were used to assess relationships between injury status in 2 groups (history of injury, and injuries sustained during the championships) and perceived landing patterns during play and podiatric variables. A significant association was found between history of lower limb and back injuries and level of competition. Open age netballers reported more injuries than the younger players. During each championship, a similar number of players (23%) were injured irrespective of playing level. 71% of these players sustained a grade 1 injury, 15.4% a grade 2 injury and 13.5% presented with severe grade 3 injuries. 2 players were diagnosed with an anterior cruciate ligament injury and a further 3 players sustained a fracture during the championships. Most of the injuries were ligamentous (40.5%) with some overuse tendinitis (11.5%) problems. The injury history profiles of the elite players surveyed showed that ankle and knee injuries were the most common lower limb injuries with incidences of 58 and 22%, respectively. More than a quarter of the players had overuse type injuries (24% retropatellar pain, 38% shin soreness) and 33% complained of back problems during their careers. 18 significant relationships were found between injuries sustained during a player's career and podiatric measures. Only 22.5% of a player's foot types were classified as normal while 42% presented with rearfoot varus and 20% were grouped into pronated foot postures.

Adolescent↗
PubMed1992

Landing patterns in netball: analysis of an international game.

The passing and landing patterns among netball players were investigated by examining all the 595 passes in an international match between Australia and New Zealand. Intra-class correlations were used to test inter-observer reliability. The independence of two variables was tested using a Pearson chi 2 test and a contingency coefficient was used to assess the degree of association between variables. An inter-rater reliability in the identification of movement patterns was 0.99. Most of the landings observed in this match were on the forefoot and not the hindfoot as generally reported in controlled experiments. Only 14% of the players leapt to receive a pass compared with 76% reported earlier under controlled environments. The distribution of passing techniques unexpectedly showed that approximately 50% of all the players did not reach for the ball as it was thrown directly to them. However, over 70% of the players threw straight passes which were mainly received in the chest quadrant and other types of passes such as loop, bounce and rebound were used less frequently. Nearly 50% of all players used a right-handed pass to dispose of the ball, while the next most popular pass was to use both hands (40.2%). Landing and passing patterns differed between players in different positions. Footfall patterns on landing after a catch were associated with the trajectory of the ball.

Australia↗