Tanneke Palmans

Descriptive profile of scapulothoracic position, strength and flexibility variables in adolescent elite tennis players

Study design Descriptive study, cross-sectional design. Background Tennis requires repetitive overhead movement patterns that can lead to upper extremity injury. The scapula plays a vital role in injury-free playing. Scapular dysfunction has been associated with shoulder injury in the overhead athlete. Objectives The purpose of this study was to describe variables regarding scapular position, muscle strength and flexibility in young elite tennis players. Methods Thirty-five adolescent Swedish elite tennis players (19 boys, aged 13.6 (±1.4) years, 16 girls, aged 12.6 (±1.3) years), selected on the basis of their national ranking, underwent a clinical screening protocol consisting of: scapular upward rotation at several angles of arm elevation; isometric scapular muscle strength; and anthropometric measurement of pectoralis minor (PM) length. Results The players showed significantly more scapular upward rotation on their dominant side (p<0.001). For both genders, upper trapezius (p=0.003) and serratus anterior (p=0.01) strength was significantly greater on the dominant side, whereas middle and lower trapezius strength showed no side differences. PM was shorter on the dominant side (p<0.001), and in the female players (p=0.006) compared with the boys. Conclusion These results indicate some sports-related adaptations of young tennis players on their dominant side at the scapulothoracic level to exposure to their sport. These data may assist the clinician in the prevention and rehabilitation of sport-specific injuries in adolescent tennis players.

Age-Related, Sport-Specific Adaptions of the Shoulder Girdle in Elite Adolescent Tennis Players

CONTEXT Tennis requires repetitive overhead movements that can lead to upper extremity injury. The scapula and the shoulder play a vital role in injury-free playing. Scapular dysfunction and glenohumeral changes in strength and range of motion (ROM) have been associated with shoulder injury in the overhead athlete. OBJECTIVE To compare scapular position and strength and shoulder ROM and strength between Swedish elite tennis players of 3 age categories (<14, 14-16, and >16 years). DESIGN Cross-sectional study. SETTING Tennis training sports facilities. PATIENTS OR OTHER PARTICIPANTS Fifty-nine adolescent Swedish elite tennis players (ages 10-20 years) selected based on their national ranking. MAIN OUTCOME MEASURE(S) We used a clinical screening protocol with a digital inclinometer and a handheld dynamometer to measure scapular upward rotation at several angles of arm elevation, isometric scapular muscle strength, glenohumeral ROM, and isometric rotator cuff strength. RESULTS Players older than 16 years showed less scapular upward rotation on the dominant side at 90° and 180° (P < .05). Although all absolute scapular muscle strength values increased with age, there was no change in the body-weight-normalized strength of the middle (P = .9) and lower (P = .81) trapezius or serratus anterior (P = .17). Glenohumeral internal-rotation ROM and total ROM tended to decrease, but this finding was not statistically significant (P = .052 and P = .06, respectively). Whereas normalized internal-rotator strength increased from 14 to 16 years to older than 16 years (P = .009), normalized external-rotator and supraspinatus strength remained unchanged. CONCLUSIONS Age-related changes in shoulder and scapular strength and ROM were apparent in elite adolescent tennis players. Future authors should examine the association of these adaptations with performance data and injury incidence.

Gait Analysis With Cognitive-Motor Dual Tasks to Distinguish Fallers From Nonfallers Among Rehabilitating Stroke Patients

OBJECTIVES To evaluate fall risk in stroke patients based on single- and dual-task gait analyses, and to investigate the difference between 2 cognitive tasks in the dual-task paradigm. DESIGN Prospective cohort study. SETTING Rehabilitation hospitals. PARTICIPANTS Subacute stroke patients (N=32), able to walk without physical/manual help with or without walking aids, while performing a verbal task. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Functional gait measures were Functional Ambulation Categories (FAC) and use of a walking aid. Gait measures were evaluated by an electronic walkway system under single- and dual-task (DT) conditions. For the single-task, subjects were instructed to walk at their usual speed. One of the DTs was a verbal fluency dual task, whereby subjects had to walk while simultaneously enumerating as many different animals as possible. For the other DT (counting dual task), participants had to walk while performing serial subtractions. After inclusion, participants kept a 6-month falls diary. RESULTS Eighteen (56.3%) of the 32 included patients fell. Ten (31.3%) were single fallers (SFs), and 8 (25%) were multiple fallers (MFs). Fallers (Fs) more frequently used a walking aid and more frequently needed an observatory person for walking safely (FAC score of 3) than nonfallers (NFs). Two gait decrement parameters in counting dual task could distinguish potential Fs from NFs: decrement in stride length percentage (P=.043) and nonparetic step length percentage (P=.047). Regarding the division in 3 groups (NFs, SFs, and MFs), only MFs had a significantly higher percentage of decrement for paretic step length (P=.023) than SFs. CONCLUSIONS Examining the decrement of spatial gait characteristics (stride length and paretic and nonparetic step length) during a DT addressing working memory can identify fall-prone subacute stroke patients.

The impact of rotator cuff tendinopathy on proprioception, measuring force sensation

BACKGROUND The impact of rotator cuff tendinopathy and related impingement on proprioception is not well understood. Numerous quantitative and qualitative changes in shoulder muscles have been shown in patients with rotator cuff tendinopathy. These findings suggest that control of force might be affected. This investigation wants to evaluate force sensation, a submodality of proprioception, in patients with rotator cuff tendinopathy. METHODS Thirty-six patients with rotator cuff tendinopathy and 30 matched healthy subjects performed force reproduction tests to isometric external and internal rotation to investigate how accurately they could reproduce a fixed target (50% MVC). Relative error, constant error, and force steadiness were calculated to evaluate respectively magnitude of error made during the test, direction of this error (overshoot or undershoot), and fluctuations of produced forces. RESULTS Patients significantly overshoot the target (mean, 6.04% of target) while healthy subjects underestimate the target (mean, -5.76% of target). Relative error and force steadiness are similar in patients with rotator cuff tendinopathy and healthy subjects. Force reproduction tests, as executed in this study, were found to be highly reliable (ICC 0.849 and 0.909). Errors were significantly larger during external rotation tests, compared to internal rotation. CONCLUSION Patients overestimate the target during force reproduction tests. This should be taken into account in the rehabilitation of patients with rotator cuff tendinopathy; however, precision of force sensation and steadiness of force exertion remains unaltered. This might indicate that control of muscle force is preserved.

Measuring Eccentric Strength of the Shoulder External Rotators Using a Handheld Dynamometer: Reliability and Validity

CONTEXT Shoulder strength assessment plays an important role in the clinical examination of the shoulder region. Eccentric strength measurements are of special importance in guiding the clinician in injury prevention or return-to-play decisions after injury. OBJECTIVE To examine the absolute and relative reliability and validity of a standardized eccentric strength-measurement protocol for the glenohumeral external rotators. DESIGN Descriptive laboratory study. SETTING Testing environment at the Department of Rehabilitation Sciences and Physiotherapy of Ghent University, Belgium. PATIENTS OR OTHER PARTICIPANTS Twenty-five healthy participants (9 men and 16 women) without any history of shoulder pain were tested by 2 independent assessors using a handheld dynamometer (HHD) and underwent an isokinetic testing procedure. INTERVENTION(S) The clinical protocol used an HHD, a DynaPort accelerometer to measure acceleration and angular velocity of testing 30°/s over 90° of range of motion, and a Biodex dynamometer to measure isokinetic activity. MAIN OUTCOME MEASURE(S) Three eccentric strength measurements: (1) tester 1 with the HHD, (2) tester 2 with the HHD, and (3) Biodex isokinetic strength measurement. RESULTS The intratester reliability was excellent (0.879 and 0.858), whereas the intertester reliability was good, with an intraclass correlation coefficient between testers of 0.714. Pearson product moment correlation coefficients of 0.78 and 0.70 were noted between the HHD and the isokinetic data, showing good validity of this new procedure. CONCLUSIONS Standardized eccentric rotator cuff strength can be tested and measured in the clinical setting with good-to-excellent reliability and validity using an HHD.

Acromiohumeral Distance and 3-Dimensional Scapular Position Change After Overhead Muscle Fatigue

CONTEXT Muscle fatigue due to repetitive and prolonged overhead sports activity is considered an important factor contributing to impingement-related rotator cuff pathologic conditions in overhead athletes. The evidence on scapular and glenohumeral kinematic changes after fatigue is contradicting and prohibits conclusions about how shoulder muscle fatigue affects acromiohumeral distance. OBJECTIVE To investigate the effect of a fatigue protocol resembling overhead sports activity on acromiohumeral distance and 3-dimensional scapular position in overhead athletes. DESIGN Cross-sectional study. SETTING Institutional laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 29 healthy recreational overhead athletes (14 men, 15 women; age = 22.23 ± 2.82 years, height = 178.3 ± 7.8 cm, mass = 71.6 ± 9.5 kg). INTERVENTION(S) The athletes were tested before and after a shoulder muscle-fatiguing protocol. MAIN OUTCOME MEASURE(S) Acromiohumeral distance was measured using ultrasound, and scapular position was determined with an electromagnetic motion-tracking system. Both measurements were performed at 3 elevation positions (0°, 45°, and 60° of abduction). We used a 3-factor mixed model for data analysis. RESULTS After fatigue, the acromiohumeral distance increased when the upper extremity was actively positioned at 45° (Δ = 0.78 ± 0.24 mm, P = .002) or 60° (Δ = 0.58 ± 0.23 mm, P = .02) of abduction. Scapular position changed after fatigue to a more externally rotated position at 45° (Δ = 4.97° ± 1.13°, P < .001) and 60° (Δ = 4.61° ± 1.90°, P = .001) of abduction, a more upwardly rotated position at 45° (Δ = 6.10° ± 1.30°, P < .001) and 60° (Δ = 7.20° ± 1.65°, P < .001) of abduction, and a more posteriorly tilted position at 0°, 45°, and 60° of abduction (Δ = 1.98° ± 0.41°, P < .001). CONCLUSIONS After a fatiguing protocol, we found changes in acromiohumeral distance and scapular position that corresponded with an impingement-sparing situation.

The role of proximal dynamic joint stability in the development of exertional medial tibial pain: a prospective study

Objective To prospectively determine risk factors contributing to the development of exertional medial tibial pain (EMTP). Methods Data were prospectively collected on healthy female students in physical education, who were freshmen in 2010–2011 and 2011–2012. Eighty-six female students aged 19.38±0.85 years, were tested at the beginning of their first academic year. Kinematic parameters in the frontal and transverse plane were measured during a single-leg drop jump (SLDJ). For further analysis, the SLDJ task was divided in two phases: touchdown until maximal knee flexion (MKF) and then MKF until take-off, representing landing and push-off phase, respectively. The injury follow-up of the students was assessed using a weekly online questionnaire and a 3-monthly retrospective control questionnaire. EMTP was diagnosed by an experienced medical doctor. Cox regression analysis was used to identify the potential risk factors for the development of EMTP. Results During injury follow-up (1–2 years), 22 participants were diagnosed with EMTP. The results of this study identified that increased range of motion (ROM) in the transverse plane of hip and thorax during landing (p=0.010 and 0.026, respectively) and during push off (p=0.019 and 0.045, respectively) are predictive parameters for the development of EMTP in women. Conclusions Increased ROM values of hip and thorax in the transverse plane, which can be interpreted as impaired ability to maintain dynamic joint stability resulting in increased accessory movements, are significant contributors to the development of EMTP in women.

Multi-segment foot landing kinematics in subjects with chronic ankle instability

BACKGROUND Chronic ankle instability has been associated with altered joint kinematics at the ankle, knee and hip. However, no studies have investigated possible kinematic deviations at more distal segments of the foot. The purpose of this study was to evaluate if subjects with ankle instability and copers show altered foot and ankle kinematics and altered kinetics during a landing task when compared to controls. METHODS Ninety-six subjects (38 subjects with chronic ankle instability, 28 copers and 30 controls) performed a vertical drop and side jump task. Foot kinematics were obtained using the Ghent Foot Model and a single-segment foot model. Group differences were evaluated using statistical parametric mapping and analysis of variance. RESULTS Subjects with ankle instability had a more inverted midfoot position in relation to the rearfoot when compared to controls during the side jump. They also had a greater midfoot inversion/eversion range of motion than copers during the vertical drop. Copers exhibited less plantar flexion/dorsiflexion range of motion in the lateral and medial forefoot. Furthermore, the ankle instability and coper group exhibited less ankle plantar flexion at touchdown. Additionally, the ankle instability group demonstrated a decreased plantar flexion/dorsiflexion range of motion at the ankle compared to the control group. Analysis of ground reaction forces showed a higher vertical peak and loading rate during the vertical drop in subjects with ankle instability. INTERPRETATION Subjects with chronic ankle instability displayed an altered, stiffer kinematic landing strategy and related alterations in landing kinetics, which might predispose them for episodes of giving way and actual ankle sprains.

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).

Vibration perception threshold in relation to postural control and fall risk assessment in elderly

Abstract Purpose: This study investigates (i) the potential discriminative role of a clinical measure of peripheral neuropathy (PN) in assessing postural performance and fall risk and (ii) whether the integration of a simple screening vibration perception threshold (VPT) for PN in any physical (fall risk) assessment among elderly should be recommended, even if they do not suffer from DM. Method: One hundred and ninety-five elderly were entered in a four-group model: DM with PN (D+; n = 75), DM without PN (D−; n = 28), non-diabetic elderly with idiopathic PN (C+; n = 31) and non-diabetic elderly without PN (C−; n = 61). Posturographic sway parameters were captured during different static balance conditions (AMTI AccuGait, Watertown, MA). VPT, fall data, Mini-Mental State Examination and Clock Drawing Test were registered. Two-factor repeated-measures ANOVA was used to compare between groups and across balance conditions. Results: The groups with PN demonstrated a strikingly comparable, though bigger sway, and a higher prospective fall incidence than their peers without PN. Conclusions: The indication of PN, irrespective of its cause, interferes with postural control and fall incidence. The integration of a simple screening for PN (like bio-thesiometry) in any fall risk assessment among elderly is highly recommended. Implications for Rehabilitation The indication of peripheral neuropathy (PN), irrespective of its cause, interferes with postural control and fall incidence. Therefore, the integration of a simple screening for PN (like bio-thesiometry) in any fall risk assessment among elderly is highly recommended. It might be useful to integrate somatosensory stimulation in rehabilitation programs designed for fall prevention.