Spinal pain and nutrition in adolescents--an exploratory cross-sectional study.

BACKGROUND: Spinal pain is an important health issue for adolescents resulting in functional limitations for many and increasing the risk of spinal pain in adulthood. Whilst human and animal studies suggest nutrition could influence spinal pain, this has not been investigated in adolescents. The objective of this exploratory cross sectional study was to evaluate associations between diet and adolescent spinal pain. METHODS: This study surveyed the spinal pain (neck and back) and nutrition (specific nutrients, broad food groups, diet quality and dietary pattern) of 1424 male and female adolescents at 14 years of age, in Western Australia. RESULTS: Back or neck pain were experienced by around half of the adolescents, with females more likely to experience spinal pain. Nutrition differed between sexes and deviated from optimal intakes. Vitamin B12, eggs, cereals and meat consumption were related to spinal pain in sex specific multivariate analyses including primary carer education level and adolescent waist girth and smoking. CONCLUSIONS: The findings of this study suggest that certain aspects of diet may have an association with spinal pain in adolescence.

Is knee laxity change after ACL injury and surgery related to open kinetic chain knee extensor training load?

OBJECTIVE: The purpose of this study was to evaluate whether knee anterior laxity changes after anterior cruciate ligament injury and surgery are related to aspects of thigh muscle resistance training during rehabilitation. DESIGN: Forty-nine subjects (13 females) diagnosed with an anterior cruciate ligament-deficient knee or who had undergone anterior cruciate ligament reconstructive surgery participated in this study. The subjects trained their knee extensors in the open kinetic chain during a 6-wk program, and the relationship of aspects of training (for example, absolute resistance load) and other factors to anterior laxity change during this period were analyzed using linear regression analysis. RESULTS: The only factor found to be significantly related (r = -0.347) to anterior knee laxity change was average absolute load used in training the knee extensors. CONCLUSIONS: These results offer some early clinical support for increasing the strain on the anterior cruciate ligament graft (in patients treated with reconstruction) or other passive restraints to anterior tibial displacement, during rehabilitation after anterior cruciate ligament injury and reconstruction surgery to promote decreased knee anterior laxity.

Relationships between prolonged neck/shoulder pain and sitting spinal posture in male and female adolescents.

Neck/shoulder pain (NSP) is a common problem for adolescents and posture has been suggested as an important risk factor. The aim of this cross sectional study was to examine the relationship between prolonged NSP and habitual sitting posture in adolescents. The habitual sitting postures of 1593, 14-year-old adolescents with and without prolonged NSP were assessed using sagittal plane digital photographs. Cervicothoracic and lumbopelvic posture angles were calculated from the digital images using motion analysis software. Adolescents reported experience of NSP by questionnaire. Differences between postures of males and females and those with and without prolonged NSP were examined using independent t-tests. The relationships between cervicothoracic and lumbopelvic postures and presence of prolonged NSP were investigated using logistic regression models controlling for gender. Prolonged NSP was reported by 5.3% of the adolescents, with females reporting a higher prevalence rate (6.5%) than males (4.2%). Females also sat more erect with a more lordotic lumbar posture than males. Adolescents with prolonged NSP had more flexed cervicothoracic posture, more erect trunk and more lumbar lordosis. When gender was controlled, only lumbar lordosis was related to the presence of prolonged NSP.

Fitness, motor competence and body composition as correlates of adolescent neck/shoulder pain: an exploratory cross-sectional study.

BACKGROUND: Adolescent neck/shoulder pain (NSP) is a common and sometimes debilitating problem. Several risk factors for this condition have been investigated, but no studies have previously evaluated associations between fitness, motor competence, body composition and adolescent NSP. METHODS: 1608 males and females of mean age 14 years answered questions on their history of NSP (4 measures), and were tested for aerobic fitness, upper and lower limb power, trunk endurance, grip strength, shoulder flexibility, motor competence and anthropometric factors. Univariate and multivariate logistic regressions were used to test for associations between NSP and physical variables. RESULTS: There were significant gender differences for most physical and pain variables. After multivariate analysis, males had lower odds of NSP if they had reduced back endurance [OR: 0.66 (95% CI: 0.46-0.97)], reduced persistent control [0.42 (0.19-0.95], and increased muscle power [0.33 (0.12-0.94)], and higher odds of NSP if they had a higher basketball throw [2.47 (1.22-5.00)] and jump performance [3.47 (1.55-7.74)]. Females had lower odds for NSP if they had a reduced jump performance [0.61(0.41-0.92)], a better basketball throw [0.60(0.40-0.90)], lower shoulder flexibility [0.54 (0.30-0.98)] and a higher aerobic capacity [0.61 (0.40-0.93)], and higher odds for NSP if they had greater abdominal endurance [1.57(1.07-2.31)] and greater bimanual dexterity [1.77(1.18-2.65)]. Females showed a U shaped relationship between NSP and back endurance [low: 2.12 (1.20-3.74); high 2.12 (1.18-3.83)]. CONCLUSION: Adolescent NSP was associated with fitness and motor competence, although the associations varied with gender, and their strength was limited.

Sitting spinal posture in adolescents differs between genders, but is not clearly related to neck/shoulder pain: an observational study.

QUESTION: Is neck/shoulder pain in adolescents related to their sitting spinal posture, taking account of gender? DESIGN: Cross-sectional survey and direct observation. PARTICIPANTS: 1597 adolescents from the 'Raine' birth cohort study (781 females, 816 males) with a mean age of 14.1 years (SD 0.2). OUTCOME MEASURES: Neck/shoulder pain prevalence and gender was measured by survey. Spinal posture (7 angles) during sitting was measured from photographs. RESULTS: Life, month, and point prevalence for neck/shoulder pain among adolescents were 47%, 29%, and 5% respectively. Life prevalence was 10% higher in females than in males and month prevalence was 12% higher. When looking straight ahead, females sat with 2 degrees (95% CI 1 to 3) less neck flexion, 2 degrees (95% CI 0 to 3) less craniocervical angle, 7 degrees (95% CI 6 to 8) less cervicothoracic angle, 13 degrees (95% CI 12 to 14) less trunk angle, 10 degrees (95% CI 8 to 12) less lumbar angle, and 9 degrees (95% CI 7 to 11) more anterior pelvic tilt than males. Adolescents with neck/shoulder pain sat with 2 degrees (95% CI 1 to 3) less trunk angle, and 1 degree (95% CI 0 to 2) less cervicothoracic angle than those without pain. After controlling for gender, OR for neck/shoulder pain ever predicted by any angle ranged from 0.99 to 1.00 (range of 95% CI 0.98 to 1.01). CONCLUSION: Neck/shoulder pain is highly prevalent in Australian adolescents. Sitting spinal posture differs between males and females and differs slightly between those with and without neck/shoulder pain. However, posture was not predictive of neck/shoulder pain ever after controlling for gender.

Strength, power output and symmetry of leg muscles: effect of age and history of falling.

Risk factors for medically unexplained falls may include reduced muscle power, strength and asymmetry in the lower limbs. Conflicting reports exist about strength and there is little information about power and symmetry. Forty-four healthy young people (29.3 +/- 0.6 years), 44 older non-fallers (75.9 +/- 0.6 years), and 34 older fallers (76.4 +/- 0.8 years) were studied. Isometric, concentric and eccentric strength of the knee and ankle muscles and leg extension power were measured bilaterally. The younger group was stronger in all muscles and types of contraction than both older groups (P < 0.02-0.0001). Strength differences between the older groups occasionally reached significance in individual muscles and types of contraction but overall the fallers had 85% of the strength and 79% of the power of the non-fallers (P < 0.001). Young subjects generated more power than both older groups (P < 0.0001) and the fallers generated less than the non-fallers (P = 0.03). Strength symmetry showed an inconsistent age effect in some muscles and some contraction types. This was similar overall in the two older groups. Both older groups had greater asymmetry in power than the young (P < 0.02-0.004). Power asymmetry tended to be greater in the fallers than the non-fallers but this did not reach significance. These data do not support the suggestion that asymmetry of strength and power are associated with either increasing age or fall history. Power output showed clear differences between age groups and fall status and appears to be the most relevant measurement of fall risk and highlights the cumulative effects on function of small changes in strength in individual muscle groups.

Steadiness of quadriceps contractions in young and older adults with and without a history of falling.

Decreased steadiness of muscle force may be associated with ageing and could be a cause of falls in older people. We studied this in isometric and anisometric quadriceps contractions in healthy young and older people. The older group contained people with and without a history of medically unexplained falls. Forty-four young (aged 18-40 years) and 78 older (aged > 70 years) subjects participated. In the latter group 34 people had a history of falling (fallers) and 44 did not (non-fallers). Isometric steadiness was measured by the coefficient of variation (CoV) of force at 10, 25 and 50% maximal voluntary force (MVC). Anisometric steadiness was measured by the SD of acceleration during concentric and eccentric contractions against two external loads (1 and 5 kg). There was an overall trend for the younger subjects to be most steady and the fallers the least but the differences were not consistently significant. Isometric steadiness was unaffected by force in all groups. The fallers were less steady (P < 0.001) than both the young and non-fallers, who had similar values. During anisometric contractions, steadiness was similar with both external loads and types of contraction in all groups. During dynamic contractions the older subjects were less steady (P < 0.002). Only eccentric contractions distinguished between the two older groups, with the fallers being less steady by 31% (P = 0.013). These data indicate ageing per se is associated with decreased anisometric, but not isometric, steadiness. Greater unsteadiness during eccentric contractions in the fallers could be an important mechanism of medically unexplained falls.

Knee extensors kinetic chain training in anterior cruciate ligament deficiency.

Open kinetic chain (OKC) knee extensor resistance training has lost favour in rehabilitation of patients with knee ACLD due to concerns that this exercise is harmful to the remaining portion of the ACL and its secondary stabilizers, and will be less effective in improving function. In this randomized, single-blind clinical trial, closed and OKC knee extensor training were compared for their effects on knee laxity and function in patients with ACLD knees. Sixty-four patients with a diagnosis of knee ACLD (49 M, 15 F; mean age=30 years) were measured for knee laxity, using a ligament arthrometer, and function with the Hughston Clinic knee self-assessment questionnaire and maximal effort single leg jump testing. Between the above tests and identical tests carried out 6 weeks later, subjects trained using either open or closed kinetic chain resistance of their knee and hip extensors as part of formal physical therapy sessions three times per week for 6 weeks. The groups exhibited no statistically significant differences (p<0.083) in outcome. These results indicate that knee extensor OKC training, as used in this study, can be safely applied to patients with knee ACL deficiency, and shows no superiority to CKC training.

Effects of closed versus open kinetic chain knee extensor resistance training on knee laxity and leg function in patients during the 8- to 14-week post-operative period after anterior cruciate ligament reconstruction.

Open kinetic chain (OKC) knee extensor resistance training has lost favour in ACLR rehabilitation due to concerns that this exercise is harmful to the graft and will be less effective in improving function. In this randomized, single-blind clinical trial OKC and closed kinetic chain (CKC) knee extensor training were compared for their effects on knee laxity and function in the middle period of ACLR rehabilitation. The study subjects were 49 patients recovering from ACLR surgery (37 M, 12 F; mean age=33 years). Tests were carried out at 8 and 14 weeks after ACLR with knee laxity measured using a ligament arthrometer and function with the Hughston Clinic knee self-assessment questionnaire and single leg, maximal effort jump testing (post-test only). Between tests, subjects trained using either OKC or CKC resistance of their knee and hip extensors as part of formal physical therapy sessions three times per week. No statistically significant (one-way ANOVA, p>0.05) differences were found between the treatment groups in knee laxity or leg function. OKC and CKC knee extensor training in the middle period of rehabilitation after ACLR surgery do not differ in their effects on knee laxity or leg function. Exercise dosages are described in this study and further research is required to assess whether the findings in this study are dosage specific.