Roger Wolman

The influence of winter vitamin D supplementation on muscle function and injury occurrence in elite ballet dancers: A controlled study

OBJECTIVES Athletes who train indoors during the winter months exhibit low serum 25-hydroxyvitamin D [25(OH)D] concentrations due to a lack of sunlight exposure. This has been linked to impaired exercise performance. The purpose of this study was to assess the effects of oral vitamin D₃ supplementation on selected physical fitness and injury parameters in elite ballet dancers. DESIGN Controlled prospective study. METHODS 24 elite classical ballet dancers (intervention n=17; control n=7) participated in a controlled 4-month oral supplementation of vitamin D₃ (2000 IU per day). Isometric muscular strength and vertical jump height were measured pre and post intervention. Injury occurrence during the intervention period was also recorded by the in-house medical team. Repeated measures ANOVA and Mann-Whitney-U statistical tests were used and significance was set at p ≤ 0.05. RESULTS Significant increases were noted for the intervention group for isometric strength (18.7%, p<0.01) and vertical jump (7.1%, p<0.01). The intervention group also sustained significantly less injuries than the controls during the study period (p<0.01). CONCLUSIONS Oral supplementation of vitamin D₃ during the winter months has beneficial effects on muscular performance and injury occurrence in elite ballet dancers.

Vitamin D status in professional ballet dancers: Winter vs. summer

OBJECTIVE Serum 25-hydroxyvitamin D is produced by the exposure of the skin to sunlight. Therefore athletes who train indoors, such as dancers, are vulnerable to vitamin D deficiency. The purpose of the study was to evaluate the serum 25-hydroxyvitamin D status in UK professional dancers during periods of reduced and increased sunlight exposure (i.e., winter vs. summer), and to assess the impact on bone metabolism and risk of injury. DESIGN Cohort study. METHODS 19 elite classical ballet dancers (age 26±8.86yr; height 1.66±8.84m; mass 54.3±10.47kg) were monitored over a 6 month period for 25-hydroxyvitamin D, PTH and blood serum bone turnover markers (CTX and PINP) along with injury data. Repeated measure ANOVA and Wilcoxon and Chi-square analyses were used and significance was set at p≤0.05. RESULTS Significant changes were noted between the winter and summer test dates for 25-hydroxyvitamin D (14.9ng/ml vs. 23.9ng/ml; p<0.001), PTH (38.7pg/ml vs. 26.3pg/ml; p<0.001) and PINP (89.9ng/ml vs. 67.6ng/ml; p<0.01). The oral contraceptive had a significant effect on serum 25-hydroxyvitamin D, PTH and CTX. Soft tissue injuries were significantly lower in summer compared to winter period (winter=24, summer=13; p<0.05). CONCLUSIONS Professional ballerinas characterized by a high incidence of low serum 25-hydroxyvitamin D levels which improve marginally in the summer. These dancers also demonstrate a higher injury incidence in the winter. Oral contraception seems to increase serum 25-hydroxyvitamin D levels and has a positive effect on bone metabolism.

Acute Effects of Vitamin D3 Supplementation on Muscle Strength in Judoka Athletes: A Randomized Placebo-Controlled, Double-Blind Trial.

Objective:Indoor athletes have been shown to be prone to vitamin D3 deficiency. The aim of the study was to examine the acute effects of vitamin D supplementation on muscle function using isokinetic dynamometry. Design:Randomized placebo-controlled, double-blind study. Setting:Institutional. Participants:Adult male white national level judoka athletes (n = 22) who were involved in full-time training. Exclusion criteria were vitamin supplementation, overseas travel to sunny climes, and/or an injury incurred during the last 3 months before testing. Interventions:Subjects were randomly allocated to the treatment (150 000IU vitamin D3) or placebo and given blinded supplements by an independent researcher. Participants were tested twice, 8 days apart, on a Monday morning before the start of judo training and after 2 days of rest. A 5 to 7 mL of blood sample was collected followed by isokinetic concentric quadriceps and hamstring muscle function assessments on the right leg at 30 and 200°·s−1. Main Outcome Measures:Repeated-measures analysis of variance was used to analyze isokinetic muscle force and serum 25(OH)D3. Regression to the mean was used to examine changes in 25(OH)D3 levels over the study period. Results:The treatment group demonstrated a significant increase in serum 25(OH)D levels (34%, P ⩽ 0.001) and muscle strength (13%, P = 0.01) between days 1 and 8. No significant differences were found for the placebo group for the same period. Conclusions:A single bolus of 150 000IU vitamin D3 had a significant positive effect on serum 25(OH)D levels and muscle function in vitamin D insufficient elite indoor athletes. Clinical Relevance:Serum 25(OH)D3 levels of indoor athletes should be monitored throughout the year and especially during winter months. Beneficial responses, in muscle strength and serum 25(OH)D3, to 1 dose of vitamin D3 supplementation can be observed within 1 week of ingestion. Muscle strength is linked to serum 25(OH)D levels.

Osgood-Schlatter disease

An active 14 year old boy, accompanied by his father, presents because of persisting knee pain, which is worse during and after sports. In 1903, Osgood and Schlatter separately described a painful overuse condition affecting the tibial tuberosity. Osgood-Schlatter disease is a common cause of knee pain in children, associated with growth spurts, peaking in boys at about 12 to 15 years and girls at about 10 to 12 years. It is more common in boys than girls and up to 30% of children present with bilateral symptoms.1 Cadaveric and radiological studies have led to the theory that Osgood-Schlatter disease may be caused by forceful contractions of the quadriceps muscles at the proximal tibial apophysis insertion leading to multiple small avulsion fractures.2 This may lead to a firm enlargement of the tibial tubercle over time. The age of onset may be caused by the relative imbalance of strengthening quadriceps muscles compared with the growing bone. It is also …

Changes in bone turnover markers during the close season in elite football (soccer) players.

OBJECTIVES Bone turnover marker changes in response to physical activity are well documented. There is, however, little information on the extent and severity of skeletal de-conditioning in athletes in response to rest periods. This study analyses changes in markers of bone resorption and bone formation during the close season within the squad of an English Football Association Championship club. DESIGN Evaluation was performed on the first team football squad just before the end of the 2007/2008 football season and again 8 weeks later before pre-season testing and training. METHOD Bone resorption was measured by serum concentration of C-terminal telopeptide (CTx) and bone formation by serum concentration of the N-terminal propeptide of type I procollagen (PINP). Twenty football players aged from 18 to 36 years (mean 23.6 years) were included in the study. RESULTS The mean change in CTx during the close season was +0.14 ng/ml (95% CI: 0.21 to 0.06, p=0.001). The mean change in PINP was -10.8 ng/ml (95% CI: -3.9 to -17.7, p=0.004). CONCLUSIONS In professional football players, a close season rest of 8 weeks results in an increase in bone resorption and a decrease in bone formation markers. This imbalance between formation and resorption may have negative effects on bone mass and structure. Future research should focus on understanding the many factors that could contribute to the changes found in the study during the close season.

Groin pain in athletes: a consequence of femoral head avascular necrosis after testicular cancer chemotherapy.

A thletes frequently present with groin pain. Development after testicular cancer chemotherapy can indicate avascular necrosis (osteonecrosis) of the femoral head. Sports medicine specialists and allied professionals must promptly recognize this condition, which affects young male athletes. Femoral head collapse can result in hip replacement. We present 2male athletes who required joint resurfacing surgery.

Treatment of Lumbar Pars Interarticularis Stress Injuries in Athletes With Intravenous Bisphosphonates: Five Case Studies

INTRODUCTION Stress fractures of the pars interarticularis are a recognized cause of lower back pain in athletes. Sports that involve repetitive flexion, extension, and rotation of the spine are associated with a higher incidence of this condition. Treatment measures, such as activity restriction, bracing, and physical therapy, are not always effective in the management of pars fractures. Recently, bisphosphonates have been viewed with interest as pharmaceutical agents that could be of use in promoting healing of stress fractures. In this retrospective case series, we report the use of intravenous pamidronate or ibandronate in athletes with lumbar pars interarticularis stress injuries who were seen at the Royal National Orthopaedic Hospital Sports Medicine Clinic between 2006 and 2009.

Quadriceps Traumatic Myositis Ossificans in a Football Player: Management With Intravenous Pamidronate

Myositis ossificans (MO) can be a significant complication of traumatic muscle contusion. Bisphosphates have been used in management of heterotopic ossification after spinal cord injury, but there is a lack of evidence with respect to MO in the sporting population. We present a case of a 14-year-old male football player with posttraumatic quadriceps MO, treated with 2 doses of intravenous pamidronate. This was associated with improvement in clinical features and imaging and a reduced urinary N-terminal telopeptide, a marker of bone turnover. This case demonstrates that bisphosphonates may be a potential treatment option in MO.

Epidemiology: knee injuries in female athletes.

Why are female athletes more susceptible to knee ligament injuries than male athletes performing the same activities? Several theories have been put forward to explain this phenomenon.

The Effect of Vitamin D Supplementation in Elite Adolescent Dancers on Muscle Function and Injury Incidence: A Randomised Double-Blind Study.

PURPOSE A number of studies have noted low levels of Vitamin D in dancers and this has been associated with increased risk of injuries and decreased muscular strength indices. The aim of the present study was to examine whether vitamin D supplementation over a 4-month period can improve muscle function and injury incidence. METHODS Eighty-four participants volunteered, exclusion criteria and drop out (19%) reduced cohort to 67 (f=29, m=38; 17-19yrs). Participants were randomly assigned to either an intervention or placebo group (2:1 ratio). All provided a venous blood sample pre and post the 4-month study period. The intervention group received 120,000IU vitamin D to be taken over a 1-week period and the placebo group received the same number of inert pills. Participants completed a series of muscle function tests pre and post the monitoring period. Injury incidence was recorded by the independent health team at the school. RESULTS Pre-intervention 6% of the cohort were vitamin D deficient, 81% were insufficient and 13% had sufficient levels; post-intervention 53% were insufficient and 47% were sufficient. The intervention group reported a significant increase in serum 25(OH)D3 (57%; p<0.00) and isometric strength (7.8%; p=0.022) but not muscular power. There was a significant association between traumatic injury occurrence for the intervention and control groups (10.9% vs. 31.8%; p < .02). CONCLUSION Vitamin D supplementation decreased the numbers of deficient and insufficient participants within this cohort. The intervention group reported a small significant increase in muscle strength that was negatively associated with traumatic injury occurrence.