Associations of neck muscle strength and cervical spine mobility with future neck pain and disability: a prospective 16-year study.

BACKGROUND: Neck pain has been associated with weaker neck muscle strength and decreased cervical spine range of motion. However, whether neck muscle strength or cervical spine mobility predict later neck disability has not been demonstrated. In this 16-year prospective study, we investigated whether neck muscle strength and cervical spine mobility are associated with future neck pain and related disability in women pain-free at baseline. METHODS: Maximal isometric neck muscle strength and passive range of motion (PROM) of the cervical spine of 220 women (mean age 40, standard deviation (SD) 12 years) were measured at baseline between 2000 and 2002. We conducted a postal survey 16 years later to determine whether any subjects had experienced neck pain and related disability. Linear regression analysis adjusted for age and body mass index was used to determine to what extent baseline neck strength and PROM values were associated with future neck pain and related disability assessed using the Neck Disability Index (NDI). RESULTS: The regression analysis Beta coefficient remained below 0.1 for all the neck strength and PROM values, indicating no association between neck pain and related disability. Of the 149 (68%) responders, mean NDI was lowest (3.3, SD 3.8) in participants who had experienced no neck pain (n = 50), second lowest (7.7, SD 7.1) in those who had experienced occasional neck pain (n = 94), and highest (19.6, SD 22.0) in those who had experienced chronic neck pain (n = 5). CONCLUSIONS: This 16-year prospective study found no evidence for an association between either neck muscle strength or mobility and the occurrence in later life of neck pain and disability. Therefore, screening healthy subjects for weaker neck muscle strength or poorer cervical spine mobility cannot be recommended for preventive purposes.

Use of conservative therapy before and after surgery for carpal tunnel syndrome.

BACKGROUND: Conservative therapies are typically offered to individuals who experience mild or intermittent symptoms of carpal tunnel syndrome (CTS) or postoperatively to subjects who have undergone carpal tunnel release. Although long-term studies report mostly positive results for carpal tunnel release, knowledge on the need for conservative treatments following surgery is scarce. The aim of this retrospective cohort study was to examine the use of conservative therapies before and after carpal tunnel releasing surgery. METHODS: Of 528 patients who underwent carpal tunnel release surgery in the study hospital during the study period, 259 provided sufficiently completed questionnaires (response rate 49 %). The patients completed a questionnaire battery including a sociodemographic, medical history and symptom questionnaire, the Boston Carpal Tunnel Syndrome Questionnaire, 6-item CTS symptoms scale and EuroQoL 5D. Frequencies of conservative therapies pre- and postoperatively were calculated. Association between Pain VAS and satisfaction with treatment were examined in patient groups according to the use of conservative therapies. RESULTS: Of all patients, 41 (16 %) reported receiving only preoperative, 18 (7 %) reported receiving only postoperative, 157 (60 %) reported receiving both pre- and postoperative conservative therapies and 43 (17 %) did not receive any therapies. Preoperative use of conservative therapies was more common in females than males (82 % vs. 64 %; p = 0.002), but postoperatively no significant gender difference was observed. The patients who received conservative therapies were younger than non-users in both the preoperative (median age 59 vs. 66; p < 0.001) and postoperative (59 vs. 66; p = 0.04) phases. The patients reported high satisfaction with their treatment and simultaneous improvement in Pain VAS scores. Those receiving conservative therapies only preoperatively reported the highest satisfaction. CONCLUSIONS: While the use of conservative therapies decreased after surgery, a large proportion of the patients received these adjunct interventions. Patients reported high satisfaction with their treatment one year post surgery. Pain outcome seems to be closely related to satisfaction with treatment. LEVEL OF EVIDENCE: Level III.

Enhanced rehabilitation guidance after arthroscopic capsulolabral repair of the shoulder: a randomized controlled trial.

OBJECTIVE: To compare the effects of a 12-month home-based exercise program to usual care in patients after arthroscopic capsulolabral repair of the shoulder. DESIGN: Randomized controlled trial. SETTING: Outpatient physical and rehabilitation medicine clinic. SUBJECTS: Forty-five patients (mean age: 35 years; standard deviation (SD): 10 years) who underwent arthroscopic capsulolabral repair due to labral lesion were randomized into an exercise group (EG) or a control group (CG). INTERVENTION: The EG received a 12-month home-based additional exercise program with four physiotherapy follow-up visits, while the CG received standard postoperative exercise instructions. MAIN MEASURES: Self-reported shoulder disability was assessed with the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and quality of life with the Short-Form (SF)-36 Health Survey. The function of the operated shoulder was evaluated with strength and range of motion measurements. RESULTS: No between-group differences were observed in any of the outcomes at the follow-up. Mean ASES score improved by 16 (95% confidence interval (CI): 10-23) points from the baseline 78 (SD: 17) in the EG and 13 (95% CI: 7-19) points from the baseline 79 (SD: 17) in the CG. Both groups achieved a significant improvement in the dimensions of Physical Functioning, Role-Physical, and Bodily Pain of the SF-36 and in every aspect of strength and range of motion measures. In EG, exercise adherence was moderate (52%) during the first six months and poor (22%) during the last six months. CONCLUSION: Home-based additional exercises with four outpatient follow-up visits did not improve outcome after arthroscopic capsular repair of the shoulder.

Structural validity of the Boston Carpal Tunnel Questionnaire and its short version, the 6-Item CTS symptoms scale: a Rasch analysis one year after surgery.

BACKGROUND: The Boston Carpal Tunnel Questionnaire (BCTQ) and its shorter version, the Six-Item Carpal Tunnel Symptoms Scale (CTS-6), are widely used for assessing function and/or symptoms in patients with carpal tunnel syndrome. This study examined the structural validity of the BCTQ and CTS-6 among patients who had undergone surgery for treatment of carpal tunnel syndrome. METHODS: The data for this cross-sectional analysis were obtained from 217 adult patients who had undergone carpal tunnel release surgery 1 year earlier. All patients completed the CTS-6, Symptom Severity Scale (SSS) and Functional Status Scale (FSS) of the BCTQ at 12 months after surgery. The Rasch Measurement Theory (RMT) was applied to investigate the unidimensionality, residual correlation, differential item functioning, scale coverage/targeting, and person separation of the CTS-6, SSS and FSS of the BCTQ. RESULTS: The FSS showed unidimensionality and good scale and item fit. All items showed ordered response category thresholds. Eight of the FSS items displayed differential item functioning favoring age or gender. The multidimensional structure of the CTS-6 was absorbed by creating a testlet for frequency of symptoms or testlets for pain and numbness. The testlets supported unidimensionality in the BCTQ SSS. One item in the CTS-6 and two items in the BCTQ SSS showed differential item functioning favoring age or gender. Four items in the BCTQ SSS and two items in the CTS-6 exhibited disordered response category thresholds. Merging of the relevant response categories led to ordered response category thresholds. The person separation indices were 0.73, 0.86 and 0.77 for the CTS-6, BCTQ SSS and FSS, respectively. CONCLUSIONS: Based on the RMT analysis, the CTS-6 has superior psychometric properties compared to the BCTQ SSS in surgically treated patients. The CTS-6 might be more accurate when separated into item sets measuring pain or numbness. The FSS of the BCTQ has acceptable construct validity, although gender differences at some ages were observed in responses.

Pulsed electromagnetic field therapy in the treatment of pain and other symptoms in fibromyalgia: A randomized controlled study.

Low-energy pulsed electromagnetic field (PEMF) therapy has been suggested as a promising therapy to increase microcirculation, which is of great concern in patients with fibromyalgia. This study evaluated the effectiveness of PEMF therapy on the treatment of fibromyalgia. A group of 108 women with fibromyalgia were allocated to a 12-week treatment period with an active Bio-Electro-Magnetic-Energy-Regulation (BEMER) device and a similar treatment period with an inactive device. Each patient received active and sham treatments in a random order. Pain and stiffness were assessed on a visual analog scale (VAS, scale 0-100 mm), and functional status was assessed by the Fibromyalgia Impact Questionnaire (FIQ). Mean VAS pain scores before the active and sham treatment periods were 66 (SD 22) and 63 (SD 22), respectively. After treatment periods, mean VAS pain scores had decreased significantly in active treatment, -12, 95% CI [-18, -6], and in sham treatment, -11, 95% CI [-17, -5]. Similarly, the decrease in stiffness and FIQ index after both treatments was statistically significant. However, per-protocol analysis showed no differences between active and sham treatments at any of the outcomes. This study demonstrated that low-energy PEMF therapy was not efficient in reducing pain and stiffness or in improving functioning in women with fibromyalgia. Bioelectromagnetics. 39:405-413, 2018. © 2018 Wiley Periodicals, Inc.

Construct validity and reliability of the Finnish version of the Knee Injury and Osteoarthritis Outcome Score.

BACKGROUND: The Knee Injury and Osteoarthritis Outcome Score (KOOS) is a commonly used knee assessment and outcome tool in both clinical work and research. However, it has not been formally translated and validated in Finnish. The purpose of this study was to translate and culturally adapt the KOOS questionnaire into Finnish and to determine its validity and reliability among Finnish middle-aged patients with knee injuries. METHODS: KOOS was translated and culturally adapted from English into Finnish. Subsequently, 59 patients with knee injuries completed the Finnish version of KOOS, Western Ontario and McMaster Osteoarthritis Index (WOMAC), Short-Form 36 Health Survey (SF-36) and Numeric Pain Rating Scale (Pain-NRS). The same KOOS questionnaire was re-administered 2 weeks later. Psychometric assessment of the Finnish KOOS was performed by testing its construct validity and reliability by using internal consistency, test-retest reliability and measurement error. The floor and ceiling effects were also examined. RESULTS: The cross-cultural adaptation revealed only minor cultural differences and was well received by the patients. For construct validity, high to moderate Spearman's Correlation Coefficients were found between the KOOS subscales and the WOMAC, SF-36, and Pain-NRS subscales. The Cronbach's alpha was from 0.79 to 0.96 for all subscales indicating acceptable internal consistency. The test-retest reliability was good to excellent, with Intraclass Correlation Coefficients ranging from 0.73 to 0.86 for all KOOS subscales. The minimal detectable change ranged from 17 to 34 on an individual level and from 2 to 4 on a group level. No floor or ceiling effects were observed. CONCLUSION: This study yielded an appropriately translated and culturally adapted Finnish version of KOOS which demonstrated good validity and reliability. Our data indicate that the Finnish version of KOOS is suitable for assessment of the knee status of Finnish patients with different knee complaints. Further studies are needed to evaluate the predictive ability of KOOS in the Finnish population.

Preferences and Avoidance of Sleeping Positions Among Patients With Chronic Low Back Pain: A Cross-Sectional Study.

Background Chronic low back pain (CLBP) is a common issue among the working-age population. Sleeping position may affect CLBP, with the prone position commonly suggested to be avoided. This study aims to examine the relationship between preferred and avoided sleeping positions and to explore the frequency of increased pain in various sleeping positions among patients with nonspecific CLBP and pain and disability levels. Methods This cross-sectional study included all adult patients referred for specialist consultation for CLBP at the outpatient clinic of the Central Hospital of Central Finland's spine department. Pain intensity was measured using a visual analog scale (VAS), and disability was assessed with the Oswestry Disability Index (ODI). Patients completed a questionnaire detailing the main sleeping positions and positions avoided due to low back pain (LBP). Results The study enrolled 375 consecutive patients, with a mean age of 51 ± 17 years; 64% (n=240) were female. The mean VAS score was 63 ± 24, and the mean Oswestry Index was 38 ± 18%. The majority of patients (87%, n=327) reported sleeping in a side-lying position, followed by supine (47%, n=176) and prone (22%, n=82) positions. A negative correlation was found between age and the preference for sleeping in the prone position. No significant gender differences in sleep positions were observed (p=0.69). Sleep was disturbed in 77% of patients (n=289) due to LBP, and 87% (n=327) reported difficulties due to LBP when getting up. Overall, 92% of participants (n=345) experienced difficulties sleeping or getting up in the morning due to LBP. Many patients avoided certain positions due to pain: 42% (n=157) avoided the prone position, 35% (n=131) the back, 15% (n=56) the left side, and 13% (n=49) the right side. Although the prone position was most commonly linked with pain, especially among women, our findings suggest that any sleeping position could potentially exacerbate pain in individuals with CLBP. Conclusions This study highlights the variability in how sleeping positions affect pain in patients with nonspecific CLBP. While the prone position is most frequently associated with increased pain, individual preferences and responses vary significantly, and often sidelying and supine positions provoke pain. The diversity in sleeping positions that exacerbate pain highlights the need for tailored advice in the management of patients with CLBP.

Trunk muscle activation of core stabilization exercises in subjects with and without chronic low back pain.

BACKGROUND: Weakness and atrophy in trunk muscles have been associated with chronic low back pain (CLBP). OBJECTIVE: This study aimed to identify isometric exercises resulting the highest trunk muscle activity for individuals with and without CLBP. METHODS: Fourteen males with CLBP and 15 healthy age-matched healthy subjects were recruited for this study. Muscle activity during maximal voluntary isometric contraction (MVIC) was measured for a comparative reference with surface electromyography (sEMG) from six trunk muscles. Thereafter maximum EMG amplitude values were measured during eleven trunk stability exercises. The maximal EMG activity in each exercise relative to the MVICs was analyzed using generalizing estimating equations (GEE) models with the unstructured correlation structure. RESULTS: The GEE models showed statistically significant differences in muscle activity between exercises within both groups (p< 0.001), with no significant differences between groups (p> 0.05). The highest muscle activity was achieved with the hip flexion machine for multifidus, side pull with a resistance band for lumbar extensors, side and single-arm cable pull exercises for thoracic extensors, rotary plank and the hip flexion machine for abdominal. CONCLUSION: This study found five isometric trunk exercises that exhibited highest muscle activity depending on muscle tested, with no significant difference between individuals with and without CLBP.

Effects of a progressive aquatic resistance exercise program on the biochemical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial.

BACKGROUND: Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. METHODS: A minimum of 80 volunteers who meet the inclusion criteria will be recruited from the local population through newspaper advertisements. Following initial assessment volunteers will be randomised into two groups. The intervention group will participate in a progressive aquatic resistance exercise program of 1-hour duration 3 times a week for four months. The control group will be asked to maintain normal care during this period. Primary outcome measure for this study is the biochemical composition of knee cartilage measured using quantitative magnetic resonance imaging; T2 relaxation time and delayed gadolinium-enhanced magnetic resonance imaging techniques. In addition, knee cartilage morphology as regional cartilage thickness will be studied. Secondary outcomes include measures of body composition and bone traits using dual energy x-ray absorptiometry and peripheral quantitative computed tomography, pain, function using questionnaires and physical performance tests and quality of life. Measurements will be performed at baseline, after the 4-month intervention period and at one year follow up. DISCUSSION: This randomised controlled trial will investigate the effect a progressive aquatic resistance exercise program has on the biochemical composition of cartilage in post-menopausal women with mild knee osteoarthritis. This is the first study to investigate what impact aquatic exercise has on human articular cartilage. In addition it will investigate the effect aquatic exercise has on physical function, pain, bone and body composition and quality of life. The results of this study will help optimise the prescription of aquatic exercise to persons with mild knee osteoarthritis. TRIAL REGISTRATION: ISRCTN65346593.

Interactive multiobjective optimization for finding the most preferred exercise therapy modality in knee osteoarthritis.

BACKGROUND: There are no explicit guidelines or tools available to support clinicians in selecting exercise therapy modalities according to the characteristics of individual patients despite the apparent need. OBJECTIVE: This study develops a methodology based on a novel multiobjective optimization model and examines its feasibility as a decision support tool to support healthcare professionals in comparing different modalities and identifying the most preferred one based on a patient's needs. METHODS: Thirty-one exercise therapy modalities were considered from 21 randomized controlled trials. A novel interactive multiobjective optimization model was designed to characterize the efficacy of an exercise therapy modality based on five objectives: minimizing cost, maximizing pain reduction, maximizing disability improvement, minimizing the number of supervised sessions, and minimizing the length of the treatment period. An interactive model incorporates clinicians' preferences in finding the most preferred exercise therapy modality for each need. Multiobjective optimization methods are mathematical algorithms designed to identify the optimal balance between multiple conflicting objectives among available solutions/alternatives. They explicitly evaluate the conflicting objectives and support decision-makers in identifying the best balance. An experienced research-oriented physiotherapist was involved as a decision-maker in the interactive solution process testing the proposed decision support tool. RESULTS: The proposed methodology design and interactive process of the tool, including preference information, graphs, and exercise suggestions following the preferences, can help clinicians to find the most preferred exercise therapy modality based on a patient's needs and health status; paving the way to individualize recommendations. CONCLUSIONS: We examined the feasibility of our decision support tool using an interactive multiobjective optimization method designed to help clinicians balance between conflicting objectives to find the most preferred exercise therapy modality for patients with knee osteoarthritis. The proposed methodology is generic enough to be applied in any field of medical and healthcare settings, where several alternative treatment options exist.KEY MESSAGESWe demonstrate the potential of applying Interactive multiobjective optimization methods in a decision support tool to help clinicians compare different exercise therapy modalities and identify the most preferred one based on a patient's needs.The usability of the proposed decision support tool is tested and demonstrated in prescribing exercise therapy modalities to treat knee osteoarthritis patients.

Cross-cultural adaptation and validation of the Kerlan-Jobe Orthopaedic Clinic shoulder and elbow score in Finnish-speaking overhead athletes.

BACKGROUND: The Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow score (KJOC) is developed to evaluate the shoulder and elbow function in overhead athletes. To date, the score has not been adapted into Finnish language. The aim of this study was to perform a cross-cultural adaptation of the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow score (KJOC) into Finnish language and evaluate its validity, reliability, and responsiveness in overhead athletes. METHODS: Forward-backward translation method was followed in the cross-cultural adaptation process. Subsequently, 114 overhead athletes (52 males, 62 females, mean age 18.1 ± 2.8 years) completed the Finnish version of KJOC score, Disabilities of the Arm, Shoulder and Hand (DASH), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and RAND-36 to assess validity of the KJOC score. To evaluate reliability and responsiveness, the participants filled in the KJOC score 16 days and eight months after the first data collection. Validity, reliability, and responsiveness of the Finnish KJOC score were statistically tested. RESULTS: Minor modifications were made during the cross-cultural translation and adaptation process, which were related to culture specific terminology in sports and agreed by an expert committee. Construct validity of the KJOC score was moderate to high, based on the correlations with DASH (r = - 0.757); DASH sports module (r = - 0.667); ASES (r = 0.559); and RAND-36 (r = 0.397) questionnaires. Finnish KJOC score showed excellent internal consistency (α = 0.92) and good test-retest reliability (2-way mixed-effects model ICC = 0.77) with acceptable measurement error level (SEM 5.5; MDC 15.1). Ceiling effect was detected for asymptomatic athletes in each item (23.2-61.1%), and for symptomatic athletes in item 5 (47.4%). Responsiveness of the Finnish KJOC score could not be confirmed due to conflicting follow-up results. CONCLUSION: The Finnish KJOC score was found to be a valid and reliable questionnaire measuring the self-reported upper arm status in Finnish-speaking overhead athletes.

Impact or No Impact for Women With Mild Knee Osteoarthritis: A Bayesian Meta-Analysis of Two Randomized Controlled Trials With Contrasting Interventions.

OBJECTIVE: To predict the probability of a benefit from 2 contrasting exercise programs for women with a new diagnosis of mild knee osteoarthritis, and to estimate the short- and long-term effects of aquatic resistance training (ART) and high-impact aerobic land training (HLT) compared with a control. METHODS: Original data sets from 2 previously conducted randomized controlled trials were combined and used in a Bayesian meta-analysis. Group differences in multiple response variables were estimated. Variables included cardiorespiratory fitness, dynamic maximum leg muscle power, maximal isometric knee extension and flexion force, pain, other symptoms, and quality of life. The statistical model included a latent commitment variable for each female participant. RESULTS: ART had a 55-71% probability of benefits in the outcome variables, and as the main effect, the intervention outperformed the control in cardiorespiratory fitness, with a probability of 71% immediately after the intervention period. HLT had a 46-63% probability of benefits after intervention with the outcome variables, but differently from ART; the positive effects of physical performance fade away during the follow-up period. Overall, the differences between groups were small, and the variation in the predictions between individuals was high. CONCLUSION: Both interventions had benefits, but ART has a slightly higher probability of long-term benefits on physical performance. Because of high individual variation and no clear advantage of one training method over the other, personal preferences should be considered in the selection of the exercise program to ensure highest commitment to training.

Maternal risk factors of urinary incontinence during pregnancy and postpartum: A prospective cohort study.

INTRODUCTION: Urinary incontinence (UI) during pregnancy is a common health problem. Vaginal delivery in particular affects the pelvic floor and increases the risk of pelvic floor dysfunctions. This prospective cohort study was conducted to investigate the incidence of UI during pregnancy and three months postpartum and determine the risk factors underlying UI. METHODS: In total, 547 volunteer women were recruited from the maternity clinic of a tertiary hospital. The participants filled out a questionnaire twice, one in the second trimester and the other three months after delivery. A multivariate logistic regression model with forward stepwise selection was used to analyze known risk factors for UI. RESULTS: The prevalence of UI during pregnancy was 39.5% and three months after childbirth 16.1%. Twenty-two percent of participants had pre-existing UI compared to 41.0% of the 88 women with UI three months postpartum. UI before pregnancy (OR 2.2), during pregnancy (OR 3.8) and primiparity (OR 2.3) were significantly associated with postpartum UI. CONCLUSIONS: Women with UI before or during pregnancy and who are primiparous are at increased risk for postpartum UI. To prevent and reduce the risk factors contributing to UI, pregnant women should be routinely counseled.

Effect of biomechanical footwear on upper and lower leg muscle activity in comparison with knee brace and normal walking.

AIM: To evaluate the activity of knee stabilizing muscles while using custom-made biomechanical footwear (BF) and to compare it when walking barefoot and with a knee brace (Unloader®). METHODS: Seventeen healthy working-aged (mean age: 29 years; standard deviation: 8 years) individuals participated. The knee brace was worn on the right knee and BF in both legs. Surface electromyography (sEMG) data was recorded bilaterally from vastus medialis (VM), semitendinosus (ST), tibialis anterior (TA) and lateral gastrocnemius (LG) muscles during walking, and repeated-measures ANOVA with a post-hoc t-test was used to determine differences between the different walking modalities (barefoot, brace and BF). RESULTS: Averaged sEMG was significantly higher when walking with BF than barefoot or knee brace in the ST muscles, in the right LG, and left TA muscle. It was significantly lower when walking with the brace compared to barefoot in the right ST and LG muscles, and left TA muscle. Analysis of the ensemble-averaged sEMG profiles showed earlier activation of TA muscles when walking with BF compared to other walking modalities. CONCLUSION: BF produced greater activation in evaluated lower leg muscles compared to barefoot walking. Thus BF may have an exercise effect in rehabilitation and further studies about its effectiveness are warranted.

Effects of Exercise on Patellar Cartilage in Women with Mild Knee Osteoarthritis.

PURPOSE: This study aims to investigate the effects of exercise on patellar cartilage using T2 relaxation time mapping of magnetic resonance imaging in postmenopausal women with mild patellofemoral joint osteoarthritis (OA). METHODS: Eighty postmenopausal women (mean age, 58 (SD, 4.2) yr) with mild knee OA were randomized to either a supervised progressive impact exercise program three times a week for 12 months (n = 40) or a nonintervention control group (n = 40). Biochemical properties of cartilage were estimated using T2 relaxation time mapping, a parameter sensitive to collagen integrity, collagen orientation, and tissue hydration. Leg muscle strength and power, aerobic capacity, and self-rated assessment with the Knee Injury and Osteoarthritis Outcome Score were also measured. RESULTS: After intervention, full-thickness patellar cartilage T2 values had medium-size effect (d = 0.59; 95% confidence interval, 0.16 to 0.97; P = 0.018); the change difference was 7% greater in the exercise group compared with the control group. In the deep half of tissue, the significant exercise effect size was medium (d = 0.56; 95% confidence interval, 0.13 to 0.99; P = 0.013); the change difference was 8% greater in the exercise group compared with controls. Furthermore, significant medium-size T2 effects were found in the total lateral segment, lateral deep, and lateral superficial zones in favor of the exercise group. Extension force was 11% greater (d = 0.63, P = 0.006) and maximal aerobic capacity was 4% greater (d = 0.55, P = 0.028) in the exercise group than in controls. No changes in Knee Injury and Osteoarthritis Outcome Score emerged between the groups. CONCLUSIONS: Progressively implemented high-impact and intensive exercise creates enough stimuli and exerts favorable effects on patellar cartilage quality and physical function in postmenopausal women with mild knee OA.

Effects of high-impact training on bone and articular cartilage: 12-month randomized controlled quantitative MRI study.

Osteoarthritis and osteoporosis often coexist in postmenopausal women. The simultaneous effect of bone-favorable high-impact training on these diseases is not well understood and is a topic of controversy. We evaluated the effects of high-impact exercise on bone mineral content (BMC) and the estimated biochemical composition of knee cartilage in postmenopausal women with mild knee osteoarthritis. Eighty women aged 50 to 66 years with mild knee osteoarthritis were randomly assigned to undergo supervised progressive exercise three times a week for 12 months (n = 40) or to a nonintervention control group (n = 40). BMC of the femoral neck, trochanter, and lumbar spine was measured by dual-energy X-ray absorptiometry (DXA). The biochemical composition of cartilage was estimated using delayed gadolinium-enhanced magnetic resonance imaging (MRI) cartilage (dGEMRIC), sensitive to cartilage glycosaminoglycan content, and transverse relaxation time (T2) mapping that is sensitive to the properties of the collagen network. In addition, we evaluated clinically important symptoms and physical performance-related risk factors of falling: cardiorespiratory fitness, dynamic balance, maximal isometric knee extension and flexion forces, and leg power. Thirty-six trainees and 40 controls completed the study. The mean gain in femoral neck BMC in the exercise group was 0.6% (95% CI, -0.2% to 1.4%) and the mean loss in the control group was -1.2% (95% CI, -2.1% to -0.4%). The change in baseline, body mass, and adjusted body mass change in BMC between the groups was significant (p = 0.005), whereas no changes occurred in the biochemical composition of the cartilage, as investigated by MRI. Balance, muscle force, and cardiorespiratory fitness improved significantly more (3% to 11%) in the exercise group than in the control group. Progressively implemented high-impact training, which increased bone mass, did not affect the biochemical composition of cartilage and may be feasible in the prevention of osteoporosis and physical performance-related risk factors of falling in postmenopausal women.

Neuromuscular performance and body mass as indices of bone loading in premenopausal and postmenopausal women.

The strong association between body mass and skeletal robusticity has been attributed to increasing skeletal loading with increasing mass. However, it is unclear whether body mass is merely a coarse substitute for bone loading rather than a true independent predictor of bone strength. As indices of neuromuscular performance, impulse and peak power were determined from vertical ground reaction force during a maximal counter movement jump test in 221 premenopausal and 82 postmenopausal women. Bone compressive (BSI(d) g(2)/cm(4)) and bending (SSImax(mid) mm(3)) strength indices were measured with peripheral quantitative computed tomography (pQCT) at the distal ((d)) and midshaft ((mid)) sites of the tibia. A two-step forced regression model for predicting bone strength indices was constructed. Age, height and body mass were entered first, followed by impulse as an indicator of skeletal loading. The basic model explained 14% (P<0.001) of the variance in BSI(d) in the premenopausal group and 16% (P=0.004) in the postmenopausal group, and 32% (P<0.001) and 25% (P<0.001) of the variance in SSImax(nud) respectively. Entering impulse into the model increased the explanatory power by 9% (P<0.001) and 7% (P<0.001) for BSI(d) and by 8% (P<0.001) and 12% (P<0.001) for SSImax(mid). Furthermore, impulse replaced body mass as an independent significant factor explaining the variance in bone strength. These results indicate that neuromuscular performance should be measured and preferred over body mass in models predicting skeletal robusticity.