BIOMECHANICAL ISSUES IN SPORTS PHYSIOTHERAPY AND REHABILITATION

In the last decades the number of people participating in sports and leisure time exercise activity has increased tremendously (Westerstahl et al., 2003). Due to this raise in participation the incidence of sports injuries increased, which resulted in a boost for medical interventions. For example, in the Netherlands with a population of about 15 million, there is an allover incidence of 3 injuries per 1000 hours spent on sports. One of these 3 injuries needed medical care (van Mechelen et al., 1992). Many injured athletes or leisure time sporting persons not only consult their sports physician (team physician), but also rely on the professionalism of the sports physiotherapists to increase the speed of their recovery and reduce time off of their sports and training (either competitive or a lower level of exercising). Sports physiotherapy is a specialty widely recognized as a profession with its own body of knowledge and as such represented in the World Confederation of Physical Therapy (WCPT) by the International Federation of Sports Physiotherapy (IFSP). As members of the sports medical team, sports physiotherapists are active in the prevention and rehabilitation of sports related lesions. Sports physiotherapists work with athletes of all ages and abilities, at individual and group levels, to prevent injury, restore optimal function and contribute to the enhancement of sports performance after injury, using sports-specific knowledge, skills and attitudes to achieve best clinical practice (Bulley &. Donaghy, 2005). Furthermore, sports physiotherapists are pioneers in their field, critically challenging, evaluating practice and developing new knowledge through research. However, for many years, sports physiotherapists have been relying too much on authority and non-scientific methods rather than on hard evidence for their clinical decision-making. With the risk of oversimplifying, it can be stated that many injuries are the result of a biomechanical “overuse” of the musculoskeletal system, either in an acute (trauma) or a chronic (fatigue) state. The rehabilitation of injured athletes to their functional pre-injury status is confronted with the loading capability of the injured tissue and its interaction with the known training principles (variation, overloading, specificity and recovery). Depending on the progression of the wound healing, the injured tissue may (and must) receive more and more loading in order to heal and regain functionality. Therefore, restoration of function will depend merely on the phases in which the immunological system is restoring the injured tissue (Cabri & Gomes-Pereira in E. Müller et al., 1998). For example, in muscle injuries, it is known that these phases of repair are linked with the amount of loading the injured tissue can bear (loading capability) and that early mobilization will contribute to increased efficacy of repair (Järvinen et al., 2005). In this context, biomechanical studies contribute much to the knowledge of loading on the musculoskeletal tissues during (rehabilitation) exercises, both quantitatively and qualitatively

Intramuscular Oxygenation and Muscle Activity of Extensor Carpi Radialis Brevis During Piano Performance: An Observational Study

BACKGROUND: Repetitive piano movements have been associated with playing-related musculoskeletal disorders (PRMDs) such as forearm myalgia and symptoms of lateral epicondylopathy. Despite the high prevalence of PRMDs among pianists, there is poor understanding regarding the underlying physiological mechanisms. Intramuscular oxygenation may play a role in the development of PRMDs. Therefore, this observational study aimed to explore the effect variability of playing piano repertoire on the oxygenation of the extensor carpi radialis brevis (ECRB). METHODS: Surface electromyography (EMG) activity and intramuscular oxygenation data (using near-infrared spectroscopy, NIRS) of the left and right ECRB were recorded in 13 conservatory piano students (8 female, 5 male, mean age 23.54 ± 3.24 years) while playing piano repertoire (virtuoso piece or études) for 20 minutes. From the oxygenation data, relative changes (in the percentage of the baseline measurements at rest) were calculated. RESULTS: For all participants, the oxygenated hemoglobin of the left ECRB over the piano play presented an averaged decline to the baseline resting value, with a sample mean for left ECRB of –7.48% and –11.88% for the right ECRB, ranging from –15.53% to –2.00% and –19.12% to –3.93%, respectively. The deoxygenated hemoglobin ranged in the left ECRB from –5.39% to 39.14% and from –9.37% to 54.01% in the right ECRB. The change in total hemoglobin ranged from –5.35% to 16.80% for the left ECRB and –12.10% to 10.37% for the right ECRB. EMG activity (in % maximal voluntary contraction) presented a mean of 16.85% (range 11.86 to 24.43) for the left ECRB and 23.65% (range 14.46 to 37.91) for the right ECRB. This pilot study presented a Pearson’s r between the averaged oxygenated hemoglobin and EMG of –0.60 for the right ECRB and –0.48 for the left ECRB. CONCLUSION: Piano performance induced an average decline in oxygenated hemoglobin in the left and right ECRB, which differed largely between the specific pieces played. The EMG activity can partially explain these differences. Further research is needed to explore the impact of a ‘dynamic index’ reflecting the piece’s dynamic characteristics and the individual oxygenation characteristics. Med Probl Perform Art 2023;38(4):214–223

Can usual gait speed be used as a prognostic factor for early palliative care identification in hospitalized older patients? A prospective study on two different wards

Background Timely palliative care in frail older persons remains challenging. Scales to identify older patients at risk of functional decline already exist. However, factors to predict short term mortality in older hospitalized patients are scarce. Methods In this prospective study, we recruited patients of 75 years and older at the department of cardiology and geriatrics. The usual gait speed measurement closest to discharge was chosen. We used the risk of dying within 1 year as parameter for starting palliative care. ROC curves were used to determine the best cut-off value of usual gait speed to predict one-year mortality. Time to event analyses were assessed by COX regression. Results On the acute geriatric ward (n = 60), patients were older and more frail (assessed by Katz and iADL) in comparison to patients on the cardiology ward (n = 82); one-year mortality was respectively 27 and 15% (p = 0.069). AUC on the acute geriatric ward was 0.748 (p = 0.006). The best cut-off value was 0.42 m/s with a sensitivity and specificity of 0.857 and 0.643. Slow walkers died earlier than faster walkers (HR 7.456, p = 0.011), after correction for age and sex. On the cardiology ward, AUC was 0.560 (p = 0.563); no significant association was found between usual gait speed and survival time. Conclusions Usual gait speed may be a valuable prognostic factor to identify patients at risk for one-year mortality on the acute geriatric ward but not on the cardiology ward

Changes in balance coordination and transfer to an unlearned balance task after slackline training: a self-organizing map analysis

How humans maintain balance and change postural control due to age, injury, immobility or training is one of the basic questions in motor control. One of the problems in understanding postural control is the large set of degrees of freedom in the human motor system. Therefore, a self-organizing map (SOM), a type of artificial neural network, was used in the present study to extract and visualize information about high-dimensional balance strategies before and after a 6-week slackline training intervention. Thirteen subjects performed a flamingo and slackline balance task before and after the training while full body kinematics were measured. Range of motion, velocity and frequency of the center of mass and joint angles from the pelvis, trunk and lower leg (45 variables) were calculated and subsequently analyzed with an SOM. Subjects increased their standing time significantly on the flamingo (average +2.93 s, Cohen’s d = 1.04) and slackline (+9.55 s, d = 3.28) tasks, but the effect size was more than three times larger in the slackline. The SOM analysis, followed by a k- means clustering and marginal homogeneity test, showed that the balance coordination pattern was significantly different between pre- and post-test for the slackline task only (χ2 = 82.247; p 0.001). The shift in balance coordination on the slackline could be characterized by an increase in range of motion and a decrease in velocity and frequency in nearly all degrees of freedom simultaneously. The observation of low transfer of coordination strategies to the flamingo task adds further evidence for the task-specificity principle of balance training, meaning that slackline training alone will be insufficient to increase postural control in other challenging situations

Treadmill Training in Multiple Sclerosis: Can Body Weight Support or Robot Assistance Provide Added Value? A Systematic Review

Purpose. This systematic review critically analyzes the literature on the effectiveness of treadmill training (TT), body-weight-supported TT (BWSTT), and robot-assisted TT (RATT) in persons with multiple sclerosis (MS), with focus on gait-related outcome measurements. Method. Electronic databases (Pubmed, Pedro, Web of Science, and Cochrane Library) and reference lists of articles and narrative reviews were searched. Pre-, quasi- and true-experimental studies were included if adult persons with MS were involved in TT, BWSTT, or RATT intervention studies published before 2012. Descriptive analysis was performed and two researchers scored the methodological quality of the studies. Results. 5 true- and 3 preexperimental studies (mean quality score: 66%) have been included. In total 161 persons with MS were involved (TT, BWSTT, or RATT, 6–42 sessions; 2–5x/week; 3–21 weeks). Significant improvements in walking speed and endurance were reported. Furthermore, improvements of step length, double-support time, and Expanded Disability Status Scale were found. Conclusions. There is a limited number of published papers related to TT in persons with MS, concluding that TT, BWSTT, and RATT improve the walking speed and endurance. However, it is not clear what type of TT is most effective. RCTs with larger but more homogeneous populations are needed

THREE DIMENSIONAL ARTHROKINEMATIC ANALYSIS OF THE LATE PREPARATORY PHASE OF HANDBALL THROWING

INTRODUCTION: At full cocking, functional instability of the glenohumeral (GH) joint is commonly found in handball players. In the past, 2D radiography was used to examine the in vivo translation of the humeral head (HH) on the glenoid cavity (GC). Considering the restraint validity of 2D methods to estimate 3D motion, 3D intra-articular GH kinematical data were obtained on the late cocking phase of handball throwing, using fast helical CT scanning. METHODS: Based on the CT data, 3D bone reconstructions of 3 asymptomatic and 3 functionally unstable GH joints (1 internal impingement, 2 with minor anterior GH instability) in handball players were acquired from a position with the shoulder in 90° abduction and 90° external rotation, and from a position of full cocking assessed on an individual basis. Kinematic analysis was based on a least squares method and linked to the finite helical axis (FHA) concept. After virtual disarticulation, a local frame was embedded on the GC. Subsequently, the GH FHA parameters of direction, rotation and shift were decomposed on this local frame. The displacement of the center of curvature of the HH was related to the GC. Based on an analytic error propagation model, the estimates of the rotation angle, the direction vector and the shift showed highly accurate results. The estimate of the position vector was insufficient for a mathematical analysis and therefore obtained graphically in the finite plane of motion, perpendicularly situated on the FHA. Subsequently, GH contact areal displacement of the mating articular surfaces was analyzed in this finite plane of motion. RESULTS: Towards full cocking, the HH of the asymptomatic shoulders practically did not externally/internally rotate on the local GC frame. The internal impingement demonstrated an accentuated GH external rotation, attended by a dysfunction in scapular setting, with a normal posterior translation of the HH on the GC. Minor anterior GH instability showed a diminished posterior translation of the center of the HH on the GC, as well as an accentuated external rotation. GH contact areal displacement in the normal throwing shoulders and the test case with internal impingement revealed roll behavior. The test cases with minor anterior GH instability featured a pivot. CONCLUSIONS: This research demonstrated the use of helical CT data reconstruction of joint structures with the implementation of an FHA approach to study the 6 degrees of freedom of intra-articular motion assessing a local articular embedded frame and contact areal displacements. The study provided insight in the arthrokinematics of functional instability of the GH joint at late cocking

Wavelet analyses of electromyographic signals derived from lower extremity muscles while walking or running: A systematic review.

Surface electromyography is often used to assess muscle activity and muscle function. A wavelet approach provides information about the intensity of muscle activity and motor unit recruitment strategies at every time point of the gait cycle. The aim was to review papers that employed wavelet analyses to investigate electromyograms of lower extremity muscles during walking and running. Eleven databases were searched up until June 1st 2017. The composition was based on the PICO model and the PRISMA checklist. First author, year, subject characteristics, intervention, outcome measures & variables, results and wavelet specification were extracted. Eighteen studies included the use of wavelets to investigate electromyograms of lower extremity muscles. Three main topics were discussed: 1.) The capability of the method to correctly assign participants to a specific group (recognition rate) varied between 68.4%-100%. 2.) Patients with ankle osteoarthritis or total knee arthroplasty presented a delayed muscle activation in the early stance phase but a prolonged activation in mid stance. 3.) Atrophic muscles did not contain type II muscle fiber components but more energy in their lower frequencies. The simultaneous information of time, frequency and intensity is of high clinical relevance because it offers valuable information about preand reflex activation behavior on different walking and running speeds as well as spectral changes towards high or low frequencies at every time point of the gait cycle

An Exploratory Meta-Analytic Review on the Empirical Evidence of Differential Learning as an Enhanced Motor Learning Method

Background: Differential learning (DL) is a motor learning method characterized by high amounts of variability during practice and is claimed to provide the learner with a higher learning rate than other methods. However, some controversy surrounds DL theory, and to date, no overview exists that compares the effects of DL to other motor learning methods. Objective: To evaluate the effectiveness of DL in comparison to other motor learning methods in the acquisition and retention phase. Design: Systematic review and exploratory meta-analysis. Methods: PubMed (MEDLINE), Web of Science, and Google Scholar were searched until February 3, 2020. To be included, (1) studies had to be experiments where the DL group was compared to a control group engaged in a different motor learning method (lack of practice was not eligible), (2) studies had to describe the effects on one or more measures of performance in a skill or movement task, and (3) the study report had to be published as a full paper in a journal or as a book chapter. Results: Twenty-seven studies encompassing 31 experiments were included. Overall heterogeneity for the acquisition phase (post-pre; I-2 = 77%) as well as for the retention phase (retention-pre; I-2 = 79%) was large, and risk of bias was high. The meta-analysis showed an overall small effect size of 0.26 [0.10, 0.42] in the acquisition phase for participants in the DL group compared to other motor learning methods. In the retention phase, an overall medium effect size of 0.61 [0.30, 0.91] was observed for participants in the DL group compared to other motor learning methods. Discussion/Conclusion: Given the large amount of heterogeneity, limited number of studies, low sample sizes, low statistical power, possible publication bias, and high risk of bias in general, inferences about the effectiveness of DL would be premature. Even though DL shows potential to result in greater average improvements between pre- and post/retention test compared to non-variability-based motor learning methods, more high-quality research is needed before issuing such a statement. For robust comparisons on the relative effectiveness of DL to different variability-based motor learning methods, scarce and inconclusive evidence was found