Pia Janssen

What are causes and treatment strategies for patellar-tendinopathy in female runners?

Patellar-tendinopathy (PT) is a common overuse injury in long distance runners, especially in women. Until today, no definite combinations of clinical, biomechanical, or training variables, or causative factors in the development of PT have been found. This study focused on assessing the differences in biomechanical characteristics between healthy runners (CO) and runners with PT only. We examined a total of 42 women. 21 CO and 21 PT. 3D kinematics of barefoot running was used in the biomechanical setup. Both groups were matched with respect to height and weight. After determining dropouts due to forefoot running, poor quality of data and lack of matching subjects in CO in terms of body height and weight, the final population comprised 24 subjects (CO=12, PT=12). Biomechanical evaluations indicate eccentric overloading of the quadriceps muscle group (knee extensors), increased pronation velocity as well as a lack of joint coordination as major etiological factors in the development of PT. We assume that eccentric strengthening of the knee extensors, as well as reduction of pronation velocity through orthotics, proper running shoes, and balance training will help treat and possibly prevent PT.

Feasibility and efficacy of an 8-week progressive home-based strengthening exercise program in patients with osteoarthritis of the hip and/or total hip joint replacement: a preliminary trial

The feasibility and efficacy of an additional progressive home-based strengthening exercise program (PHSEP) on subjects that already attended supervised institutional exercise therapy was investigated. Thirty-six hip patients with hip osteoarthritis (OA) and/or total hip replacement in at least one hip joint were randomly assigned to an intervention group (IG) or a control group (CG). IG (18 patients, mean age 64.9, standard deviation (SD) 7.5) followed an 8-week PHSEP in addition to their weekly institutional exercise therapy, while CG (18 patients, mean age 64.7, SD 9) solely continued the weekly institutional exercise sessions. Before and after the intervention period, strength of hip muscles was quantified applying isokinetic concentric and isometric measurements, and health-related quality of life was monitored using the SF36 questionnaire. Adherence to the exercise program was evaluated using exercise logs. The PHSEP was feasible for all subjects in IG with an adherence of 99%. Exercise logs reported that pain resulting from the PHSEP was low. Increased strength in isokinetic concentric hip adduction (13%) and isometric hip abduction (9%), adduction (12%), and flexion (7%) was found in IG in comparison to CG. The results of the SF36 did not change during the intervention period. Consequently, supervised institutional exercise therapy supplemented by a PHSEP could increase hip muscle strength in patients with hip OA and/or total hip replacement. However, further research should evaluate the optimal frequency and duration of such supplementary sessions and their potential to increase physical function and reduce pain.

Prospective analysis of intrinsic and extrinsic risk factors on the development of Achilles tendon pain in runners

There are currently no generally accepted, consistent results that clearly characterize factors causing Achilles tendon pain (AT) in runners. Therefore, we carried out a prospective study to evaluate the multifactorial influence of clinical, biomechanical (isometric strength measurements and three‐dimensional kinematics) and training‐related risk factors on the development of AT. Two hundred sixty‐nine uninjured runners were recruited and underwent an initial examination. One hundred forty‐two subjects completed their participation by submitting training information on a weekly basis over a maximal period of 1 year. Forty‐five subjects developed an overuse injury, with 10 runners suffering from AT. In an uninjured state, AT runners already demonstrated decreased knee flexor strength and abnormal lower leg kinematics (sagittal knee and ankle joint) compared with a matched control group. A relationship between years of running experience or previous overuse injuries and the development of new symptoms could not be established. The interrelationship of biomechanical and training‐specific variables on the generation of AT is evident. A combination of alterations in lower leg kinematics and higher impacts caused by fast training sessions might lead to excessive stress on the Achilles tendon during weight bearing and thus to AT in recreational runners.

Stiffness, Pain, and Hip Muscle Strength Are Factors Associated With Self-reported Physical Disability in Hip Osteoarthritis

Background:Physical disability (PD) is common among patients with osteoarthritis (OA) of the hip. Exercise therapy is proposed to be a potential intervention to reduce PD. However, the optimal targets of an exercise program are not known. Purpose:The aim of the present study was to identify factors that explain the level of self-reported PD in patients with hip OA. Knowledge of these factors will help develop specific and effective exercise programs. Methods:Data from 149 patients with hip OA (85 men and 64 women) were analyzed. Self-reported PD was quantified using the physical function subscale of the Western Ontario and McMaster index. A stepwise regression analysis was conducted to identify significant factors associated with self-reported PD. Results:Stiffness, pain, and hip muscle strength were found to be significant factors related to the level of self-reported PD in hip OA. These factors explained 59% (r2 adjusted = 0.59) of the variance. Body mass index, gender, age, and passive internal hip rotation and flexion range of motion explained only minor parts of the dependent variable self-reported PD. Discussion and Conclusion:Stiffness, pain, and hip muscle strength are associated with self-reported PD in hip OA. It is imperative that exercise treatments for hip OA include strategies to modify these factors. Further research should evaluate their role in preventing hip OA.

Comparison of distinctive gait variables using two different biomechanical models for knee joint kinematics in subjects with knee osteoarthritis and healthy controls.

BACKGROUND Gait analysis is an important instrument in clinical research and results should be objective. The purpose of this study was to quantify clinical outcomes of two biomechanical models with different anatomical coordinate systems and angle decomposition strategies for knee joint kinematics. METHODS The study was designed to compare a functional approach and a predictive approach with a single comprehensive marker set. 10 healthy subjects and 12 subjects with knee osteoarthritis were analysed. Distinctive gait variables were averaged across five trials. Agreement between methods was illustrated with the so-called levels of agreement. Differences between models were quantified using a paired t-test or Wilcoxon-Signed Rank test in case of non-normality (Shapiro-Wilk test). Unpaired t-tests/Wilcoxon tests were used to compare gait variables between healthy subjects and subjects with knee osteoarthritis, and to examine whether statistical analysis of this comparison would yield different data interpretations when using different models. FINDINGS Outcome variables differed between the functional and predictive approaches in the sagittal plane (0.1-3.1°), and transverse plane (1.0-3.7°). With respect to the range of motion in the given movement plane, variables in the sagittal plane of the knee were more consistent between methods. The functional approach was more sensitive for detecting differences between groups for sagittal plane kinematics. Statistical analysis for transverse plane kinematics differed substantially between models. INTERPRETATION Sensitivity to detect differences of kinematic data between population groups can vary between biomechanical models. Rotational gait variables are inconsistent between models and should not be used as clinical outcome variables in daily routine.

Comparison of distinctive gait variables using two different biomechanical models for ankle joint kinematics

Gait analysis is an important instrument to investigate foot and ankle biomechanics in the field of footwear design. Results of this method should be objective and comparable. The purpose of this study was to compare two different approaches to quantify ankle joint kinematics: Functionally determined joint centres/axes (FA) versus a predictive model (PA). A single comprehensive marker set was defined. Twenty-two subjects were analysed, and distinctive gait variables were averaged across five trials. Agreement between methods was quantified according to Bland & Altman (Bland and Altman 1986. Lancet, i (8476), 307). Outcome variables differed remarkably between FA and PA at the talocrural (2–9°) and subtalar joints (1–6°). Considerable differences between variables describing motion of the ankle joint complex were primarily related to the use of different rotational axes and definitions of foot segments. This should be considered when studies using different foot models are compared.

Exercise therapy in patients with hip osteoarthritis: Effect on hip muscle strength and safety aspects of exercise—results of a randomized controlled trial

Abstract Purpose: To evaluate the effect of an exercise therapy concept (the Tübingen exercise therapy approach THüKo) for increasing hip muscle strength (HMS) in patients with hip osteoarthritis (OA), and to investigate whether patients do adhere to the intervention and if there are any adverse events related to the intervention. Methods: A total of 210 hip OA patients (89 females, 121 males) were randomized into a 12-week exercise intervention (THüKo) including group sessions (1/week) and home exercising (2/week), a placebo ultrasound group (1/week) or a control group (no treatment). HMS was measured as isometric peak torque of hip abduction, adduction, flexion, and extension. Adherence to exercise and safety aspects were monitored as additional outcomes. Results: Baseline adjusted post intervention HMS of the THüKo group were higher compared to the control group (differences of 0.11–0.27 Nm/kg, p < 0.01) and to the placebo ultrasound group (differences of 0.09–0.19 Nm/kg, p < 0.01). Adherence to exercise was high (about 90%). No subject had to refuse from training because of an exercise related adverse event and exercise related pain was only of intermittent nature without sustainable adverse effects. Conclusions: The Tübingen exercise therapy approach has shown to have a significant positive effect on HMS. Its implementation has shown to be feasible and safe according to the percentage of exercise participation and the absence of sustainable adverse events.

Do lower extremity kinematics and training variables affect the development of overuse injuries in runners? - a prospective study

Background The incidence of running injuries appears to be multifactorial, e.g. with regard to training errors or kinematics of the lower extremity [1,2]. To date, studies examining differences between healthy and injured runners are mainly retrospective, and therefore not able to determine whether these differences are the cause or effect of injury. The goal of this prospective study is to evaluate whether the development of overuse injuries in initially healthy subjects is caused by alterations in lower extremity kinematics and/or training habits.

The influence of footwear and ankle kinematics on the development of overuse injuries in runners. A prospective study

Running is a popular recreational activity that has many benefits for the cardiovascular system. Despite the positive effects on the human body, between 20% and 80% of all runners suffer from an overuse injury every year (van Gent et al. 2007). The incidence of running injuries appears to be multi-factorial. Training errors, such as weekly mileage or training surfaces (Macera et al. 1989), and alterations in ankle kinematics are often considered to influence the occurrence of overuse injuries in runners (Willems et al. 2006). Supported footwear is propagated to reduce an increased amount of rearfoot motion to minimize the risk of overuse injury (Krauss et al. 2010), but evidence to substantiate this is still needed (Richards et al. 2009).

Effectiveness and efficiency of different weight machine-based strength training programmes for patients with hip or knee osteoarthritis: a protocol for a quasi-experimental controlled study in the context of health services research

Introduction Osteoarthritis is a chronic musculoskeletal disease with a major impact on the individual and the healthcare system. As there is no cure, therapy aims for symptom release and reduction of disease progression. Physical exercises have been defined as a core treatment for osteoarthritis. However, research questions related to dose response, sustainability of effects, economic efficiency and safety are still open and will be evaluated in this trial, investigating a progressive weight machine-based strength training. Methods and analysis This is a quasi-experimental controlled trial in the context of health services research. The intervention group (n=300) is recruited from participants of an offer for insurants of a health insurance company suffering from hip or knee osteoarthritis. Potential participants of the control group are selected and written to from the insurance database according to predefined matching criteria. The final statistical twins from the control responders will be determined via propensity score matching (n=300). The training intervention comprises 24 supervised mandatory sessions (2/week) and another 12 facultative sessions (1/week). Exercises include resistance training for the lower extremity and core muscles by use of weight machines and small training devices. The training offer is available at two sites. They differ with respect to the weight machines in use resulting in different dosage parameters. Primary outcomes are self-reported pain and function immediately after the 12-week intervention period. Health-related quality of life, self-efficacy, cost utility and safety will be evaluated as secondary outcomes. Secondary analysis will be undertaken with two strata related to study site. Participants will be followed up 6, 12 and 24 months after baseline. Trial registration number German Clinical Trial Register DRKS00009257. Pre-results.