Damien Van Tiggelen

Open Versus Closed Kinetic Chain Exercises in Patellofemoral Pain A 5-Year Prospective Randomized Study

Background Today, no clinical studies have been undertaken to examine the long-term effects of an open kinetic chain or closed kinetic chain program. Hypothesis The long-term follow-up results after a conservative exercise protocol are significantly worse than the short-term results. The long-term effect of closed kinetic chain training is significantly better compared to the effect of open kinetic chain training. Study Design Prospective randomized clinical trial. Methods Sixty patients were randomized into a 5-week conservative program, consisting of only closed kinetic chain exercises or only open kinetic chain exercises. Assessment of muscular characteristics, subjective symptoms, and functional performance was evaluated in this study at the time of initial physical examination, at the end of the treatment period, and 5 years later. Results At the 5-year follow-up, both groups demonstrated maintenance of good subjective and functional outcomes achieved immediately after the conservative treatment. No significant difference between both groups was observed at the 5-year follow-up for the majority of the examined parameters. However, on 3 of the 18 visual analog scales, the open kinetic chain group showed significantly less complaints compared to the closed kinetic chain group. Conclusions On the basis of these results, the authors conclude that both open kinetic chain and closed kinetic chain programs lead to an equal long-term good functional outcome.

Is Hip Muscle Weakness a Predisposing Factor for Patellofemoral Pain in Female Novice Runners? A Prospective Study

Background: Hip muscle weakness has been proposed to contribute to patellofemoral malalignment and the development of the patellofemoral dysfunction syndrome (PFDS). However, from the retrospective studies that have addressed this issue, it is still unclear if hip muscle weakness is a cause or a consequence of PFDS. Purpose: This study was undertaken to investigate if hip muscle weakness is a predisposing factor for the development of PFDS. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: Before the start of a 10-week “start to run” program, the isometric strength of the hip flexor, extensor, abductor, adductor, and external and internal rotator muscles was measured in 77 healthy female novice runners. During the 10-week training period, patellofemoral pain was diagnosed and registered by an orthopaedic surgeon. Results: Statistical analysis revealed that there was no significant difference in strength of any of the assessed hip muscle groups between the runners who did and did not develop PFDS. Logistic regression analysis did not identify a deviation in strength of any of the assessed hip muscle groups as a risk factor for PFDS. Conclusion: The findings of this study suggest that isometric hip muscle strength might not be a predisposing factor for the development of PFDS.

Prevalence and Risk Factors of Neck Pain in Military Office Workers

An extensive cross-sectional questionnaire was used to estimate the prevalence of neck pain and to identify risk factors (short term to long term) in the occurrence of neck pain in military office workers. Two standardized scales (Neck Disability Index and Tampa Scale for Kinesiophobia) allowed assessment of the impact of neck pain on the persons life and the pain-related fear avoidance. A total of 629 completed questionnaires were evaluated which revealed the following: lifetime prevalence (78%), week prevalence (53%), point prevalence (59%), year prevalence (65%) (once-only, 19%; regular, 51%; long term, 15%; never, 7%). The results of this study provided support for the role of physical and psychosocial job characteristics in the etiology of neck pain in military office workers.

Biceps femoris and semitendinosus—teammates or competitors? New insights into hamstring injury mechanisms in male football players: a muscle functional MRI study

Background The hamstring injury mechanism was assessed by investigating the exercise-related metabolic activity characteristics of the hamstring muscles using a muscle functional MRI (mfMRI) protocol. Methods 27 healthy male football players and 27 football players with a history of hamstring injuries (recovered and playing fully) underwent standardised mfMR Imaging. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exercise and a postexercise scan. The exercise-related T2 increase or the signal intensity shift between both scans was used to detect differences in metabolic activation characteristics (1) between the different hamstring muscle bellies and (2) between the injury group and the control group. Results A more symmetrical muscle recruitment pattern corresponding to a less economic hamstring muscle activation was demonstrated in the formerly injured group (p<0.05). The injured group also demonstrated a significantly lower strength endurance capacity during the eccentric hamstring exercise. Conclusions These findings suggest that the vulnerability of the hamstring muscles to football-related injury is related to the complexity and close coherence in the synergistic muscle recruitment of the biceps femoris and the semitendinosus. Discrete differences in neuromuscular coordination and activity distribution, with the biceps femoris partly having to compensate for the lack of endurance capacity of the semitendinosus, probably increase the hamstring injury risk.

Susceptibility to Hamstring Injuries in Soccer A Prospective Study Using Muscle Functional Magnetic Resonance Imaging

Background: Running-related hamstring strain injuries remain a delicate issue in several sports such as soccer. Their unremittingly high incidence and recurrence rates indicate that the underlying risk has not yet been fully identified. Among other factors, the importance of neuromuscular coordination and the quality of interplay between the different hamstring muscle bellies is thought to be a key determinant within the intrinsic injury risk. Muscle functional magnetic resonance imaging (mfMRI) is one of the tools that has been proven to be valid for evaluating intermuscular coordination. Purpose: To investigate the risk of sustaining an index or recurring soccer-related hamstring injury by exploring metabolic muscle characteristics using mfMRI. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 27 healthy male soccer players and 27 soccer players with a history of hamstring injuries underwent standardized mfMRI. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exercise, and a postexercise scan. The exercise-related T2 change, or the signal intensity shift between both scans, was used to detect differences in metabolic characteristics between (1) the different hamstring muscle bellies and (2) the prospective cohorts based on the (re)occurrence of hamstring injuries during a follow-up period of 18 months. Results: The risk of sustaining a first hamstring injury was associated with alterations in the intermuscular hierarchy in terms of the magnitude of the metabolic response after a heavy eccentric effort, with the dominant role of the semitendinosus set aside for a higher contribution of the biceps femoris (P = .017). Receiver operating characteristic (ROC) curve analysis demonstrated that this variable was significantly able to predict the occurrence of index injuries with a sensitivity of 100% and a specificity of 70% when the metabolic activity of the biceps femoris exceeded 10%. The risk of sustaining a reinjury was associated with a substantial deficit in hamstring strength endurance (P = .031). Soccer players who sustained a reinjury were only able to perform prone leg curls for a mean duration of 146.50 ± 76.16 seconds, whereas those with an injury history but no recurrence during follow-up were able to continue for a mean of 237.45 ± 110.76 seconds (95% CI, 11.9-230.5 seconds; P = .031). Conclusion: This was the first study to assess the causal relation between the intramuscular recruitment pattern and the risk of sustaining an index or secondary hamstring strain. Changes in intermuscular interplay seem to significantly increase the risk of sustaining index hamstring injuries in male amateur soccer players. Inadequate eccentric muscle endurance could be associated with an increased risk of sustaining a recurring hamstring injury.

Muscle functional MRI to evaluate quadriceps dysfunction in patellofemoral pain.

PURPOSE A dysfunction of the quadriceps muscle group has often been suggested to play an important role in the pathophysiology of patellofemoral pain (PFP). However, consensus is lacking regarding the quadriceps recruitment pattern of patients with PFP. The aim of this study was to examine by muscle functional magnetic resonance imaging if patients with PFP actually exhibit an altered activation of the muscles that play a significant role in the dynamic balance of the patella. METHODS Forty-six patients with PFP (25 female and 21 male, mean ± SD age = 25.0 ± 7.4 yr) and 30 healthy control subjects (17 female and 13 male, mean ± SD age = 21.6 ± 4.5 yr) underwent MRI of the quadriceps before and immediately after a squat exercise. The transverse relaxation time (T2) and the T2 shift were calculated for the vasti muscles. RESULTS There were no significant differences in the T2 values at rest and the T2 shift values between the patient and the control groups, except for the T2 rest value of the VMVI of females (P = 0.007). The T2 shift of the VL was significantly smaller than the T2 shift of the VMVI in both study groups (male P < 0.001 and female P = 0.044), while in females, the T2 shift of the VMO was also significantly smaller than the T2 shift of the VMVI (P = 0.027). CONCLUSIONS The activation pattern of the quadriceps is not altered in patients with PFP for both males and females. Because the relative contribution of the quadriceps muscles to a functional activity has not been modified, there is no evidence for quadriceps dysfunction.

Velocity of isokinetic trunk exercises influences back muscle recruitment patterns in healthy subjects

Isokinetic exercises at different angular velocities on Cybex devices are often used for assessment and therapy in chronic low back pain patients. Little is known about the effect of velocity of movement on the muscle activity during these exercises. The purpose of this study was to investigate both relative muscle activity and ratios of local to global muscle activity at the different velocities of isokinetic movements on a Cybex dynamometer. Fifty-three healthy employees of Belgian Defence (26 male and 27 female) aged between 20 and 57 years old voluntarily performed isometric and isokinetic exercises at four different velocities. Surface electromyographic signals of different abdominal and back muscles were recorded on both sides. Both the relative muscle activity and the local to global muscle activity ratio of the back muscles were affected by changes in velocities of isokinetic exercises. The global muscle system was more influenced by changes in velocity, than the local muscle system. Abdominal relative muscle activity and ratios were not influenced by velocity of movement. This study revealed that the velocity of isokinetic extension exercises influences the recruitment of the back muscles, meaning that protocols of training programs should be adapted in function of the focus of the therapy.

A surface electromyography based objective method to identify patients with nonspecific chronic low back pain, presenting a flexion related movement control impairment.

Movement control impairments (MCI) are often present in patients with non-specific chronic low back pain (NS-CLBP). Therefore, movement control exercises are widely used to rehabilitate patients. However, the objective assessment remains difficult. The purpose of this study was to develop a statistical model, based on logistic regression analysis, to differentiate patients with NS-CLBP presenting a flexion-related MCI from healthy subjects. This model is based on trunk muscle activation patterns measured by surface electromyography (sEMG), during movement control exercises. Sixty-three healthy male subjects and 36 male patients with a flexion-related MCI participated in this study. Muscle activity of the internal obliques, the external obliques, the lumbar multifidus and the thoracic part of the iliocostalis was registered. Ratios of deep stabilizing to superficial torque producing muscle activity were calculated to examine trunk muscle recruitment patterns during 6 different exercises. Logistic regression analyses were performed (1) to define the ratios and exercises that were most discriminating between patients and non-patients, (2) to make a predictive model. K-Fold cross-validation was used to assess the performance of the predictive model. This study demonstrated that sEMG trunk muscle recruitment patterns during movement control tests, allows differentiating NSCLBP patients with a flexion-related MCI from healthy subjects.

Proximal Neuromuscular Control Protects Against Hamstring Injuries in Male Soccer Players: A Prospective Study With Electromyography Time-Series Analysis During Maximal Sprinting:

Background: With their unremittingly high incidence rate and detrimental functional repercussions, hamstring injuries remain a substantial problem in male soccer. Proximal neuromuscular control (“core stability”) is considered to be of key importance in primary and secondary hamstring injury prevention, although scientific evidence and insights on the exact nature of the core-hamstring association are nonexistent at present. Hypothesis: The muscle activation pattern throughout the running cycle would not differ between participants based on injury occurrence during follow-up. Study Design: Case-control study; Level of evidence, 3. Methods: Sixty amateur soccer players participated in a multimuscle surface electromyography (sEMG) assessment during maximal acceleration to full-speed sprinting. Subsequently, hamstring injury occurrence was registered during a 1.5-season follow-up period. Hamstring, gluteal, and trunk muscle activity time series during the airborne and stance phases of acceleration were evaluated and statistically explored for a possible causal association with injury occurrence and absence from sport during follow-up. Results: Players who did not experience a hamstring injury during follow-up had significantly higher amounts of gluteal muscle activity during the front swing phase (P = .027) and higher amounts of trunk muscle activity during the backswing phase of sprinting (P = .042). In particular, the risk of sustaining a hamstring injury during follow-up lowered by 20% and 6%, with a 10% increment in normalized muscle activity of the gluteus maximus during the front swing and the trunk muscles during the backswing, respectively (P < .024). Conclusion: Muscle activity of the core unit during explosive running appeared to be associated with hamstring injury occurrence in male soccer players. Higher amounts of gluteal and trunk muscle activity during the airborne phases of sprinting were associated with a lower risk of hamstring injuries during follow-up. Hence, the present results provide a basis for improved, evidence-based rehabilitation and prevention, particularly focusing on increasing neuromuscular control of the gluteal and trunk muscles during sport-specific activities (eg, sprint drills, agility drills).

A Didactical Approach for Musculoskeletal Physiotherapy: The Planetary Model

Objective Musculoskeletal physiotherapy has become a well-recognized and respected sub-discipline within the physiotherapy profession. The emergence of the biopsychosocial theory and the implementation of new insights into the pain mechanisms have been two of the most powerful catalysts for change at work within this profession. The fast evolution during past decades gave rise to the need for a structured framework. The purpose of this article is to introduce a didactical model which focuses on the relevant key elements within musculoskeletal physiotherapy. Findings A didactical model is put forward in the form of a “planetary model.” The planetary model is not a new model, but is a didactic representation mainly inspired by an adapted model of the International Classification of Functioning, Disability and Health [ICF]. The structure of the ICF is reflected in a vertical plan, whereas the pain mechanisms and psychosocial factors surround this vertical structure, reflecting their continuous interaction with the different components of the vertical axis. Conclusions The planetary model enables the therapist to systematically analyze and appraise the impact of the different components as a basis for clinical decisions and aims to contribute to a more efficient way of managing patients.