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Background In aging, muscle stiffness is considered as one of the factors associated with the reduction of force generation capability. There have been inconsistent findings on age-related alteration in the passive stiffness of quadriceps muscle in the female adults. Thus, the aim of this study was to determine the effect of aging on the shear moduli of the superficial muscle heads of the quadriceps and to explore its relationship with knee extension force. Methods Passive shear moduli of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) were measured at rest using shear wave elastography in 20 young and 20 senior female adults. Measurements were repeated at four knee joint positions, that is, 30°, 60°, 90°, and 105° of knee flexion. Maximal isometric voluntary knee extension force was assessed at 30°, 60°, and 90° of knee flexion. Results As per our findings, senior adults were determined to have significantly higher passive muscle shear moduli in the RF (by 34% – 68%; all p p p = 0.020). The RF shear modulus was negatively correlated to the maximal isometric voluntary contraction force measured at 60° (r = − 0.485, p = 0.030) in senior adults. Conclusions Senior female adults had greater passive stiffness at the superficial muscle heads of the quadriceps muscles when measured at long muscle length. Among the senior female adults, the passive stiffness of RF has been determined to have a negative association with the knee extensor force only at 60° knee flexion. No significant association was noted for other angles and muscles.

We aimed to establish consensus for reporting recommendations relating to participant characteristics in tendon research. A scoping literature review of tendinopathy studies (Achilles, patellar, hamstring, gluteal and elbow) was followed by an online survey and face-to-face consensus meeting with expert healthcare professionals (HCPs) at the International Scientific Tendon Symposium, Groningen 2018. We reviewed 263 papers to form statements for consensus and invited 30 HCPs from different disciplines and geographical locations; 28 completed the survey and 15 attended the meeting. There was consensus that the following data should be reported for cases and controls: sex, age, standing height, body mass, history of tendinopathy, whether imaging was used to confirm pathology, loading tests, pain location, symptom duration and severity, level of disability, comorbidities, physical activity level, recruitment source and strategies, and medication use history. Standardised reporting of participant characteristics aims to benefit patients and clinicians by guiding researchers in the conduct of their studies. We provide free resources to facilitate researchers adopting our recommendations.

Context:Reduction of the subacromial space (SAS) during arm elevation may contribute to rotator cuff (RC) tendinopathy. The effects of scapular taping on the SAS in athletes with and without RC tendinopathy are unknown.Objective:To investigate the immediate effects of scapular taping on the SAS in athletes with and without RC tendinopathy.Design:Randomized controlled study with repeated measures.Setting:University laboratory.Participants:A total of 43 male volleyball players (17 asymptomatic and 26 with RC tendinopathy, mean age = 22.9 [3.5] y) participated in the study.Intervention:Three scapular taping protocols—no taping (control), taping with tension (therapeutic taping), and taping without tension (sham taping).Main Outcome Measures:Ultrasound measurements of the SAS with the arm at 0° and 60° of shoulder abduction, and the change in the SAS between 0° and 60° of shoulder abduction (SAS0°–60°) were calculated.Results:Athletes with RC tendinopathy demonstrated larger SAS with therapeutic taping at 60° of shoulder abduction (6.9 [1.9] mm vs 5.8 [1.7] mm, mean difference = 1.1 mm, 95% confidence interval, −1.80 to −0.39,P = .002) when compared with the no taping condition. The tendinopathy group also showed less reduction in the SAS with therapeutic taping during SAS0°–60°(2.0 [1.4] mm vs 2.8 [1.4] mm,P = .02) when compared with the no taping condition. When tape was applied to the scapula in asymptomatic athletes, our results showed a relatively small increase in the SAS with therapeutic taping during arm resting at 0° of abduction when compared with the no taping condition (8.7 [0.9] mm vs 8.3 [0.8] mm, mean difference = 0.4 mm, 95% confidence interval, −0.71 to −0.11,P = .01).Conclusions:Athletes with RC tendinopathy demonstrated less reduction of the SAS with rigid scapular taping during early arm abduction. Such observation was not evidenced in asymptomatic athletes.

BackgroundThe absence of any agreed-upon tendon health-related domains hampers advances in clinical tendinopathy research. This void means that researchers report a very wide range of outcome measures inconsistently. As a result, substantial synthesis/meta-analysis of tendon research findings is almost futile despite researchers publishing busily. We aimed to determine options for, and then define, core health-relateddomainsfor tendinopathy.MethodsWe conducted a Delphi study of healthcare professionals (HCP) and patients in a three-stage process. In stage 1, we extracted candidate domains from clinical trial reports and developed an online survey. Survey items took the form: ‘The ‘candidate domain’is important enough to be included as a core health-related domain of tendinopathy’; response options were: agree, disagree, or unsure. In stage 2, we administered the online survey and reported the findings. Stage 3 consisted of discussions of the findings of the survey at the ICON (International Scientific Tendinopathy Symposium Consensus) meeting. We set 70% participant agreement as the level required for a domain to be considered ‘core’; similarly, 70% agreement was required for a domain to be relegated to ‘not core’ (see Results next).ResultsTwenty-eight HCP (92% of whom had >10 years of tendinopathy experience, 71% consulted >10 cases per month) and 32 patients completed the online survey. Fifteen HCP and two patients attended the consensus meeting. Of an original set of 24 candidate domains, the ICON group deemed nine domains to be core. These were: (1) patient rating of condition, (2) participation in life activities (day to day, work, sport), (3) pain on activity/loading, (4) function, (5) psychological factors, (6) physical function capacity, (7) disability, (8) quality of life and (9) pain over a specified time. Two of these (2, 6) were an amalgamation of five candidate domains. We agreed that seven other candidate domainswere notcore domains: range of motion, pain on clinician applied test, clinical examination, palpation, drop out, sensory modality pain and pain without other specification. We were undecided on the other five candidate domains of physical activity, structure, medication use, adverse effects and economic impact.ConclusionNine core domains for tendon research should guide reporting of outcomes in clinical trials. Further research should determine the best outcome measures for each specific tendinopathy (ie, core outcome sets).

This study aims to compare the isometric strength of hip abductors and external rotators in male athletes with and without patellar tendinopathy (PT), and to examine the correlation between hip strength, pain, and functional scores. Sixty male athletes (30 with PT and 30 controls) were recruited from local volleyball and basketball teams. The isometric strength of the hip abductors and external rotators was quantified using a belt-stabilized handheld dynamometer. This study used the visual analog scale (VAS) and the Victorian Institute of Sport Assessment-Patella (VISA-p) questionnaire to measure the intensity of pain and functional scores in athletes with PT, respectively. The normalized isometric strength of the hip abductors and external rotators was significantly less in the PT group compared with controls. In subjects with PT, the normalized isometric strength was decreased by 22.0% (p = 0.000) in the hip abductors and by 20.0% in the hip external rotators (p = 0.004), compared with controls. Significant correlations were found between the normalized isometric strength of the hip abductors and intensity of pain (r = − 0.70; p

To examine the effect of scapular taping on the activity onset of scapular muscles and the scapular kinematics during arm elevation in volleyball players with rotator cuff (RC) tendinopathy.Randomized placebo-controlled repeated measures METHODS: Twenty-six male volleyball players with RC tendinopathy (mean age=23.6±3.3years) participated in the study. Electromyography (EMG) activity onset of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT) and serratus anterior (SA) and the three-dimensional scapular kinematics quantified by using an acromial marker cluster method were compared with three scapular taping protocols, namely, no taping, therapeutic taping, and placebo taping.The MT, LT and SA activated significantly earlier in both therapeutic taping (all p0.005) and placebo taping conditions than no taping conditions (all p0.002). There was a small increase in the scapular upward rotation when therapeutic taping and no taping conditions were compared (p=0.007).Scapular taping may enhance the neuromotor control of the scapular muscles. Whether it provides adequate support for normal scapular kinematics during arm movement in athletes with RC tendinopathy await for further studies.

Background Supraspinatus tendinopathy is one of the common causes of subacromial pain syndrome (SAPS) in overhead athletes. Changes in tendon vascularity have been reported in painful tendons; however, the prevalence and distribution have not been investigated in young overhead athletes. Methods We conducted a cross-sectional study of 47 overhead athletes (male, 31; female, 16) aged 18 to 36 years with SAPS for >3 months. A sonographer graded the severity of the tendinopathy and area of vascularization. Ultrasound imaging was used to measure supraspinatus tendon thickness, vascularity, and resting subacromial space. A self-written program was used to semiquantify the intensity of vascularity, expressed as the vascular index. Results The majority (87.2%) of the participants had signs of tendinopathy in the supraspinatus tendon, and 40 (85.1%) of the tendinopathic tendons had vascularity. The majority (66.0%) of the vascularized subjects presented with minimal increase in vascularity, and 19.1% had moderate to severe vascularization. Most (79.2%) of the vascularization was observed in the pericortical region. The vascular index was negatively correlated with the resting subacromial space in male athletes with a reduced subacromial space (ρ = −0.63; P = .038). Conclusion Of overhead athletes with SAPS, 87.2% had supraspinatus tendinopathy with minimal to moderate vascularization, with the majority of vascularization occurring in the pericortical region. In male athletes with a reduced subacromial space, greater vascularity in the supraspinatus tendon was associated with a smaller resting subacromial space.

To compare tendon strain and stiffness between athletes with patellar tendinopathy and healthy controls, and explore whether the intensity of pain and dysfunction were related to the mechanical properties of the tendon. Thirty-four male athletes with patellar tendinopathy and 13 healthy controls matched by age and activity levels were recruited. The in vivo mechanical properties of the patellar tendon were examined by ultrasonography and dynamometry. In subjects with patellar tendinopathy, the intensities of self-perceived pain (maximal pain in the past 7 days and pain during a single-legged declined-squat test) using the visual analogue scale and the assessment of functional disability using the Victorian Institute of Sport Assessment—patellar questionnaire, were collected. In subjects with patellar tendinopathy, tendon strain was significantly reduced by 22% (8.9 ± 3.7 vs. 14.3 ± 4.7%, P = 0.005) when compared with healthy controls. There was no significant group difference in tendon stiffness (P = 0.27). Significant negative correlations between tendon strain and the maximal self-perceived pain over 7 days (r = −0.37, P = 0.03), and pain during a single-legged declined-squat test (r = −0.37, P = 0.03) were detected. A trend of significant positive correlation was found between tendon stiffness and pain during a single-legged declined-squat test (r = 0.30, P = 0.09). Our findings show that tendon strain is reduced in athletes with patellar tendinopathy, and a lower tendon strain is associated with a greater magnitude of pain perceived.

Eccentric exercise is commonly used as a form of loading exercise for individuals with patellar tendinopathy. This study investigated the change of mechanical properties and clinical outcomes and their interrelationships after a 12-week single-legged decline-board exercise with and without extracorporeal shockwave therapy (ESWT).Randomized controlled trial.Outpatient clinic of a university.Thirty-four male in-season athletes with patellar tendinopathy for more than 3 months were randomized into exercise and combined groups.The exercise group received a 12-week single-legged decline-squat exercise, and the combined group performed an identical exercise program in addition to a weekly session of ESWT in the initial 6 weeks.Tendon stiffness and strain were examined using ultrasonography and dynamometry. Visual analog scale and Victoria Institute of Sports Assessment-patella (VISA-p) score were used to assess pain and dysfunction. These parameters were measured at preintervention and postintervention.Significant time effect but no significant group effect on the outcome measures; significant reduction in tendon stiffness (P = 0.02) and increase in tendon strain (P = 0.00); and reduction of intensity of pain (P = 0.00) and dysfunction (P = 0.00) were observed. Significant correlations between changes in tendon stiffness and VISA-p score (ρ = -0.58, P = 0.05); alteration in tendon strain, pain intensity (ρ = -0.63, P = 0.03); and VISA-p score (ρ = 0.60, P = 0.04) were detected after the exercise program.Eccentric exercise-induced modulation on tendon mechanical properties and clinical symptoms are associated in athletes with patellar tendinopathy.

Introduction Tendinopathy (local tendon pain associated with physical activity) is a challenge to treat despite recent advances. One factor contributing to this challenge is our limited ability to synthesise/meta-analyse research findings, which is further compounded by a lack of valid outcome measures. We determined the core outcome domains against which outcome measures could be recommended. Materials and methods We conducted a Delphi study of patients and health care professionals (HCP) in two parts: an online survey and consensus meeting. Online survey items were extracted from clinical trial reports. Agree, disagree, or unsure were options in response to: ‘The ‘item’ is important enough to be included in a core domain set of tendinopathy’. A-priori criterion of ≥70% participant agreement was deemed for selection of a core domain. Results 32 patients and 28 HCP (92% had >10 years of tendinopathy experience, 71% consulted >10 cases per month) completed the online survey. 2 patients and 15 HCP attended the consensus meeting. Of the original 24 items (from trial reports); 9 were core: Patient overall rating, participation, pain on activity/loading, disability, function, physical function capacity, quality of life, psychology, and pain over a specified timeframe. Eight items were not core domains: range of motion, palpation, clinical examination, structure, pain on examination or without other specification, drop out, and sensory modality pain. Remaining seven items did not meet criterion. Conclusion The core domain set serves as a guide for reporting of outcomes in clinical trials. Further research should determine these outcomes for each specific tendon.

Torsional malalignment was detected in subjects with medial knee osteoarthritis (KOA) but few studies have reported the effect of torsional deformity on knee joint loads during walking. Therefore, this study examined the relationships between lower limb torsional alignments and knee joint loads during gait in people with symptomatic medial KOA using cross-sectional study design. Lower limb alignments including tibial torsion, tibiofemoral rotation and varus/valgus alignments in standing were measured by EOS low-dose bi-planar x-ray system in 47 subjects with mild or moderate KOA. The external knee adduction moment (KAM), flexion moment (KFM) and the KAM index which was defined as (KAM/ (KAM+KFM)*100) during walking were analyzed using a motion analysis system so as to estimate the knee loads. Results revealed externaltibial torsion was positively associated with KAM in subjects with moderate KOA (r = 0.59, p = 0.02) but not in subjects with mild KOA. On the contrary, significant association was found between knee varus/valgus alignment and KAM in the mild KOA group (r = 0.58, p

To investigate the passive muscle tension of the quadriceps muscle heads in male athletes clinically diagnosed with patellar tendinopathy (PT) with those of healthy controls and explore the interplay between passive muscle tension and patellar tendon stiffness. Between November 2012 and December 2013, 66 male athletes (mean age of 21.1 ± 4.4 years) were examined using supersonic shear wave imaging technology. The passive tension of the vastus lateralis (VL) and rectus femoris (RF) muscles and patellar tendon stiffness were assessed. The shear elastic modulus of the VL muscle was increased by 26.5% (P

This study aimed to determine whether pre-exercise muscle stiffness is related to the amount of muscle damage induced by an eccentric exercise and to determine whether the post-exercise increase in stiffness is homogenously distributed between the synergist muscles. Fifty healthy participants were randomly assigned to an eccentric exercise group or a control group. The shear modulus (an index of stiffness) of rectus femoris (RF), vastus lateralis (VL) and vastus medialis oblique (VMO) was measured before, immediately after and at 48 h after eccentric exercise. The maximal isometric voluntary knee extension (MVC) torque was also measured. Significant reduction in MVC torque was observed in the eccentric group both at post and 48 H when compared with pre-exercise (both p .001). RF shear modulus increased significantly when assessed at 90° of knee flexion at post and 48 H after the eccentric exercise (p = .004 and .005, respectively). Slight but significant decrease in VL shear modulus was observed at post-exercise for the eccentric group (p = .002). No change was observed in VMO. The decrease in MVC at 48 H was negatively correlated with the RF shear modulus measured at 90° of knee flexion before the exercise. Eccentric exercise induced a wide range of peak torque reduction and muscle-head specific modulation on muscle stiffness. Participants with stiffer RF muscles exhibited greater decrease in force generating capacity at 48 H after eccentric exercise.

Tendon mechanical properties are linked to sports performance and tendon-related injuries, such as tendinopathy. Whether habitual loading, such as participation in regular jumping activities, would induce adaptation on tendon mechanical properties remains unclear. Forty healthy subjects (10 sedentary, 15 volleyball players, and 15 basketball players) aged between 18 and 35 years were recruited. Supersonic shearwave imaging was used to measure the shear elastic modulus and thickness and cross-sectional area (CSA) of the proximal patellar tendons of both knees at 30° of flexion. Significant group differences in tendon shear elastic modulus were found among the three groups. In the dominant leg, reduction in tendon shear elastic modulus by 18.9 % (p = 0.018) and 48.7 % (p = 0.000) were observed in the basketball and volleyball players, respectively, when compared with sedentary subjects. In the non-dominant leg, reduction in tendon shear elastic modulus were 27.3 % (p = 0.034) and 47.1 % (p = 0.02) in the basketball and volleyball players, respectively. The athlete groups were found to have larger CSA but with similar tendon thickness than sedentary group. The CSA were larger by 24–29 % and by 22–24 % in the basketball players and volleyball players, for the dominant and non-dominant legs, respectively (all p

Athletes with rotator cuff (RC) tendinopathy demonstrate an aberrant pattern of scapular motion which might relate to deficits in the scapular muscles. This study aimed to determine whether alteration in scapular kinematics is associated with deficits in the activity onset of scapular muscles. Forty-three male volleyball players (17 asymptomatic and 26 with RC tendinopathy) joined the study. Three-dimensional scapular kinematics was quantified using an acromial marker cluster method. The activity onset of the upper (UT), middle (MT), and lower trapezius (LT), and serratus anterior (SA) during arm abduction was assessed with electromyography. Athletes with RC tendinopathy demonstrated less scapular upward rotation (6.6±2.3 vs. 8.2±1.1°, p=0.021) in the early phase of shoulder abduction from 0° to 30° when compared to asymptomatic athletes. The tendinopathy group had delayed activity onset of LT (14.1±31.4ms vs. 74.4±45.1ms, p

To establish the test-retest reliability of ultrasound measurements on acromio-humeral distance (AHD) and supraspinatus tendon thickness; and to explore their relationships with shoulder rotational strengths.Test-retest observational study.Thirty-seven individuals (age: 21.5±1.4 years) participated in this study. Twenty-four were University volleyball players with 15 healthy and 9 players with shoulder impingement syndrome (SIS). Thirteen participants were healthy untrained individuals. Ultrasound measurements of AHD and supraspinatus tendon thickness were taken, and isokinetic testing of concentric shoulder internal rotation (IR) and external rotation (ER) at a speed of 90°/s was performed.The measurement of the AHD and the supraspinatus tendon thickness indicated excellent reliability (ICC=0.922, and ICC=0.933 respectively), and the minimum detectable difference (MDD) were 2.10mm and 0.64 mm respectively. A cut-off AHD distance of 23.9 mm had a sensitivity of 0.67 and specificity of 0.71 (area under curve (AUC): 0.70; p=0.05) in identifying individuals with and without SIS. Hence, individuals with AHD larger than 23.9 mm had greater possibility of having SIS. Positive correlations were found in AHD with supraspinatus tendon thickness (r=0.36, p0.05) and shoulder external rotational strengths (r=0.47-0.62, all p0.05) and ER/IR ratios (r=0.56-0.58, all p0.05).Ultrasound measurements of AHD and tendon thickness have excellent reliability. The reported cut-off AHD highlighted the potential role of ultrasound measurements in volleyball players for early identification of SIS. The AHD was related to the supraspinatus tendon thickness and shoulder external rotation strengths. Our findings provide a scientific basis for muscle training in overhead athletes such as volleyball players.

Sports training, especially for those requiring fast and skilled movements have been reported to improve one's postural control, but the underlying sensory integration mechanism is unknown. The purpose is to explore the sensory organisation strategies for maintaining standing balance in Taekwondo practitioners, and to examine the quasi-static and dynamic balance performance in subjects with and without TKD training. Case-control study was used as a study design. Eleven subjects with low level of Taekwondo training for 1-3 years, and eleven sedentary healthy subjects were assessed with the sensory organisation tests (SOT) under six visual and somatosensory input conditions and their balance upon landing from self- or operator-triggered drop test with the eyes closed condition. The SOT measured the equilibrium scores, whereas the drop test assessed the time to stabilisation (TTS), normalised peak force and distance of antero-posterior and medial-lateral centre of pressure on landing. Results for the SOT test revealed that Taekwondo subjects performed better during stance with eyes closed on a fixed support than the untrained group (p = 0.011). For the drop tests, the untrained group was slower in postural correction as revealed by the longer TTS than the Taekwondo group after the operator-triggered drops (p = 0.018). All subjects had a larger normalised peak force in operator-triggered than self-triggered drops. In conclusion, we observed that people with low-level Taekwondo training have better balance performance than untrained subjects as shown in the SOT results and shorter TTS with the drop test. They may rely more on the somatosensory and vestibular inputs for maintaining balance. People with balance problems may benefit from Taekwondo training.

Elastography can be used to estimate the regional shear modulus of a tendon. This can advance our knowledge on the impact of patellar alignment and regional patellar tendon stiffness. This is important as patellar tendon abnormality is mainly found in the medial portion of the tendon in subjects with proximal patellar tendinopathy. This paper aims to assess the effect of patellar displacement on differential modulation on the shear modulus of the patellar tendon. Shear modulus is captured on the medial and lateral half of the patella tendon using the Axiplorer&reg, ultrasound unit in conjunction with a 4&ndash, 15 MHz, 50 mm linear transducer with the patellar being positioned in its resting, medio- and laterally displaced positions on 40 adults (19 females, 21 males). When the patellar is displaced laterally, the shear modulus is significantly increased at the medial half in both genders but decreased at the lateral half only in females. Conclusions: Elastography detects changes in regional tendon stiffness associated with alteration in patellar positions. The modulation on the shear modulus is gender and region specific.

Purpose: The objective of this study was to investigate modulation in prelanding muscle responses and its associated impact force on landing from unexpected and self-initiated drops in male basketball players with a history of bilateral multiple ankle sprains (BMAS). Methods: Prelanding EMG responses were recorded in four lower-limb muscles, together with the impact force on landing, while 20 healthy and 19 basketball players with BMAS performed unexpected, self-initiated drops from a height of 30 cm. Results: Group differences were detected after self-initiated but not unexpected drops. Two main changes in prelanding EMG responses were observed in the injured basketball players during the self-initiated drops. First, tibialis anterior (TA) was activated significantly earlier in the injured group, whereas left tensor fascia latae appeared closer to the moment of landing (P < 0.025) than in the healthy players. Second, cocontraction indexes between left TA and peroneus longus, and left TA and medial gastrocnemius, were significantly greater in the injured than in the healthy players (P < 0.025). On landing, higher magnitude-of-impact forces were observed in the injured players on the right leg (by 23%, P = 0.012). Conclusion: In basketball players with BMAS, modulation of prelanding muscle response latencies occurred in injured (ankle) and uninjured (hip) joints during self-initiated but not unexpected drops. Greater cocontraction index between the left ankle muscle pairs in preparation for landing from self-initiated drops, and a significantly higher magnitude of impact force in the right leg on landing, were observed in the injured players.

The objective of this study was to investigate the modulation of the ankle muscle electromyographic (EMG) response as a function of mental set. Thirteen young healthy subjects underwent 40 unexpected and self-initiated drops from 30 cm above two separate force-plates. Following unexpected drops, reflex activities were observed in the medial gastrocnemius (MG) and tibialis anterior (TA) at mean latencies (+/- SD) of 83.59 +/- 10.1 and 99.43 +/- 21.82 ms, respectively. Following self-initiated drops, the response latency of the MG was significantly shortened (to 71.98 +/- 10 ms, P0.05), and the TA was significantly lengthened (to 183.33 +/- 45 ms, P0.05) when compared with unexpected drops. Such a modulation was associated with a significant reduction of the impact force on landing as compared with unexpected drops (by 17%, P0.05). Interestingly, a negative correlation was found between the onset of the TA EMG response and the magnitude of the impact force on landing during expected (r= -0.66, P0.05) but not unexpected drops.

Single-cohort laboratory-based study.To identify whether plantar fascia vascularity and thickness are associated with foot pain and dysfunction in individuals with chronic plantar fasciitis. Background Altered plantar fascia vascularity and thickening of the fascia have been identified in individuals with chronic plantar fasciitis.Thirty-eight patients with chronic unilateral plantar fasciitis and 21 controls participated in this study. Proximal plantar fascia vascularization and thickness were assessed using ultrasound imaging, and pain and foot dysfunction were quantified with a visual analog scale and the Chinese version of the Foot Function Index, respectively. Paired t tests were used to assess the side-to-side differences in fascia thickness and vascularity index (VI) in the control and patient groups, and an unpaired t test was used to make comparisons with the patient group. Multiple regression analysis was performed to identify whether the VI and fascia thickness were associated with pain and foot dysfunction.There were significantly higher VI (mean ± SD, 2.4% ± 1.4%) and fascia thickness (5.0 ± 1.3 mm) values in the affected feet when compared with the unaffected feet in the patient group (VI, 1.4% ± 0.5%; fascia thickness, 3.3 ± 0.7 mm) and with the dominant side of the controls (VI, 1.6% ± 0.4%; fascia thickness, 2.9 ± 0.6 mm). After accounting for age, gender, body mass index, and duration of symptoms, the VI explained 13% and 33% of the variance in pain scores measured with a visual analog scale and the pain subscale of the Foot Function Index, respectively; the VI and fascia thickness explained 42% of the variance in the Foot Function Index.Individuals with unilateral chronic plantar fasciitis demonstrated significantly greater vascularity and thickened fascia on the affected side compared to the unaffected side and also to healthy controls. Fascia vascularity was associated independently with self-perceived pain, and both fascia vascularity and thickness were associated with foot dysfunction in patients with chronic plantar fasciitis. Public trials registry: Current Controlled Trials, ISRCTN49594569.

International audience; Although excessive tension of the upper trapezius (UT) is thought to contribute to rotator cuff tendinopathy, no study examined UT tension in athletes with and without rotator cuff tendinopathy. Here we used UT shear modulus measured using ultrasound shear wave elastography as an index of muscle stiffness/tension. The aims of this study were twofold: 1) to determine whether the UT muscle shear modulus is altered in athletes with rotator cuff tendinopathy compared to asymptomatic athletes, and 2) to detect optimal cut-off points of UT shear modulus in identifying athletes with rotator cuff tendinopathy. Forty-three male volleyball players (17 asymptomatic and 26 with rotator cuff tendinopathy, mean age = 22.9±3.5 years) participated in the study. UT shear modulus was quantified during active arm holding at 30° and 60° of shoulder abduction and passive arm positioning at 0°, 30° and 60° of shoulder abduction. During the active tasks, the UT shear modulus was higher in athletes with rotator cuff tendinopathy than the asymptomatic athletes (p = 0.002), regardless the arm position. During the passive tasks, athletes with rotator cuff tendinopathy exhibited a higher UT shear modulus than asymptomatic athletes only at 0° of shoulder abduction (13.0±2.5 kPa vs 10.2±1.8 kPa, p = 0.001). When considering the active task, an optimal cut-off shear modulus of 12.0 kPa at 30° of shoulder abduction (sensitivity = 0.84, specificity = 0.57, AUC = 0.757, p = 0.008) and 9.5 kPa at 60° of shoulder abduction (sensitivity = 0.88, specificity = 0.67, AUC = 0.816, p = 0.002) was detected. When considering the passive task at 0° of shoulder abduction, a cut-off of 12.2 kPa was found (sensitivity = 0.73, AUC = 0.817, p = 0.001). Findings from the present study show that monitoring passive and active UT muscle shear modulus may provide important information for the prevention/rehabilitation of rotator cuff tendinopathy.

To investigate whether elderly Tai Chi practitioners are better able to descend a step while performing a concurrent mental task than non-practitioners. The design includes cross-sectional study. The setting includes university-based rehabilitation center. The subjects were 16 young women, 29 elderly women, and 31 elderly women who had been practicing Tai Chi regularly for at least half a year. Pre-landing muscle response latencies in their tibialis anterior (TA) and medial gastrocnemius (MG) muscles were measured during stepping down (single task) and stepping down while performing a concurrent mental activity (dual tasking). The non-practitioners had earlier onset of muscle activity in the TA in preparation for landing than the other subjects. The response latency of the Tai Chi practitioners was not significantly different from that of the young controls. When the cognitive task was added, the pre-landing response in the TA was significantly altered in both elderly groups. Response was significantly delayed among the non-practitioners, but significantly earlier among the Tai Chi subjects. The average change in response latency was significantly greater in the non-Tai Chi group compared with the young subjects and the Tai Chi practitioners (p = 0.006). Such findings suggest that practicing Tai Chi helps the elderly maintain the same strategy as much as younger subjects during stepping down. Tai Chi practitioners seem to have a greater capacity to shift attention between mental and physical tasks than other elderly women.

Introduction In patients with tendinopathy/fasciopathy, increase in vascularisation is observed in some but not all patients. However, decrease in vascularity has been observed in those successfully treated patients. A question therefore arises as whether the changes in vascularity would be difference in patients with and without vascularisation. The objective of the present study was to delineate the temporal changes in vascularisation in patients with chronic plantar fasciitis after a course of extracorporeal shock wave therapy. Methods Thirteen eight patients with chronic plantar fasciitis (age: 47.0 ± 7.4years, BMI: 25.8 ± 3.8, duration of symptom : 3 to 36 months) participated in this study. Doppler signals were obtained in Power Doppler mode using an Esaote MyLab 70 X-view ultrasound unit with a 4–13 MHz linear transducer (Esaote, Genova, Italy) at the proximal portion of the plantar fascia at 5 time points. These include pre-, post-, 3-months, 6 months and 1 year after 6-session of extracorporeal shock wave therapy, at the treated and untreated heels. Vascularity index (VI) was computed off-line using a self-written software progam (Matlab, version 7.3.0.267R2006b). Range of interest (ROI) was drawn manually along the boundary of the proximal plantar fascia within a colour box of 1.5 * 1 cm in each image. VI was calculated as the ratio of the number of colour pixels to the total number of pixels within the ROI. Patients were categorised into vascularized and non-vascularized groups based on pre-intervention vascularisation. Results In patients with chronic plantar fasciitis, the painful heel had higher VI (2.6%) than the non-painful heel (1.5%; p = 0.000). 15 (39.5%) patents were classified as vascularized group (with VI >2.6%). VI slight increase than decrease after a course of ESWT and reached a significant level at 6-month post intervention. However, in the non-vascularized patients, significant increase in VI was observed immediately after ESWT but returned to the pre-intervention level at 3-months post intervention. In the vascularized patients, reduction of VI was observed after ESWT and the reduction reached a significant level at 6-month and maintained at 1 year post intervention (Figure 1). Discussion Changes in vascularisation were observed in patients with chronic plantar fasciitis after 6-session of ESWT at the treated but not the untreated heel. The changes in vascularisation depend on the pre-intervention vascularity. An initial increase in vascularisation was observed in the non-vascularized group but a continued decline in vascularisation was noted in the vascularized group. At 1-year post intervention, the vascularisation is similar to the non-painful heel.

Proprioceptive input has been suggested to contribute to the pre-landing muscle responses associated with drop-landing, but its precise role has yet to be delineated. This study set out to examine the relationships among ankle proprioception, pre-landing muscle responses, and landing impact on drop-landing in healthy man. Fifteen healthy male basketball players aged 18 to 26 participated in this study. Passive ankle joint repositioning errors were used to examine ankle joint proprioception. Pre-landing EMG responses in the ankle muscles and the impact force on landing were recorded while the players performed self-initiated drops from a height of 30 cm. Results demonstrated that averaged ankle repositioning errors were significantly correlated with the co-contraction indexes between left tibialis anterior and medial gastrocnemius muscles (TA/MG CoI) (r=0.67, p=0.006), and showed a trend towards a relationship with the right TA/MG CoI (r=0.47, p=0.079). TA/MG CoI from both ankles were further related to the magnitude of the total impact force on landing (r=0.54 and 0.53, respectively; p0.05). We concluded that male basketball players with less accurate ankle joint sense adopted greater co-contraction of ankle dorsiflexors and platarflexors, which was in turn associated with greater impact force at the moment of landing.

Introduction Patellar tendinopathy (PT) is one of the most common knee disorders among athletes. Changes in elasticity of the painful tendon and how these relate to the pressure pain and dysfunction remain unclear. Therefore, the present study aimed to compare the elastic properties of patellar tendons between athlete with and without unilateral PT and to examine its association with pressure pain and dysfunction Methods Thirteen male athletes with unilateral PT (age 22.9 ± 4.6 years, height 1.8 ± 0.5m and weight 76.2 ± 6.3 kg, duration of symptom 22.6 ± 22.3 months) and 20 healthy control subjects (age 24.9 ± 4.4 years, height 1.82 ± 0.60m and weight 73.4 ± 7.9 kg) joined in this study. Supersonic shear imaging technique was used to measure the elastic properties of the proximal part of the patellar tendon (SuperSonic Imagine, Aix-en-Provence, France). The mean value of Young’s modulus within the region of interest (Figure 1) was computed by the ultrasound system. Shear elastic modulus was calculated by dividing the Young’s modulus by 3 (Royer et al . 2011). The ratio of mean shear elastic modulus between the painful and non-painful knee was expressed as elastic ratio in athletes with unilateral PT. The intensity of pressure pain and dysfunction were quantified with a 10-lb force to the most painful site and the Victorian Institute of Sport Assessment-patella (VISA-P) questionnaire (Visentini et al . 1998), respectively. Results In athletes with unilateral PT, the painful tendons had higher shear elastic modulus (43.6 ± 17.9 kPa) than the non-painful side (25.8 ± 10.6 kPa) (by 68.9%; p rho = 0.62; p = 0.024) and VISA-P scores ( rho = -0.61; p = 0.026) (Figure 2). Discussion Athletes with unilateral PT had stiffer patellar tendon on the painful side than the non-painful side and the dominant side of healthy athletes. A higher ratio of elastic modulus between the painful and non-painful knee is related with a greater intensity of pressure pain and a lower VISA-P score. Such findings suggest that an increase in tendon stiffness in athletes with unilateral patellar tendinopathy is associated with the tendon pain and dysfunction. References Royer et al . J Acoust Sco Am. 2011;129(5):2757–2760 Visentini et al . J Sci Med Sport. 1998;1(1):22–28

Introduction Neovascularization of tendon is one of the characteristics in patellar tendinopathy. It had been hypothesised that the vessels or the nerves accompanying the vessels were involved in the pain mechanism in this chronic pathology. [Cook, 2004] Due to the different methods used to categorise or quantify the vascularity change by researchers [Hoksrud, 2009], the relationship between vascularity and pain is still controversial. The aim of this study was to correlate findings on vascularity using power Doppler ultrasonography (PDU) and pain measured by visual analogue scale (VAS) in patients with patellar tendinopathy. Methods PDU was performed on thirty-five jumping athletes (age range: 18–35 years, mean age 22.9 years) with patellar tendinopathy (21 unilateral, 14 bilateral). The vascularity was quantified using ultrasound images by a customised software program. Vascular index (VI) was calculated as the ratio of the number of colour pixels to the total number of pixels within a standardised selected area of proximal patellar tendon. The higher VI, the more vascular is the region. The tendons were further categorised into minimal- or moderate-vascularized groups with reference to classification rated by an experienced sonographer. The athlete then rated their knee pain level using VAS on a 10-cm continuous line marked “no pain” on one end and “worst pain” on the other, recalling the maximal pain level during activities in the last 7 days. Results Tendons VI were positively correlated to pain level in both groups (r = 0.49; p = 0.03 in minimal-vascularized group; r = 0.57; p = 0.03 in moderate-vascularized group). However, when combining both groups, the correlation was not significant (r = 0.26, p = 0.14). Discussion The computerised vascular index could be one of the indicators to reflect the severity or subjective pain level of athletes suffering from patellar tendinopathy. This study suggested that categorization was indicated to reflect this correlation. The pain mechanism in tendinopathy might be different in tendons with minimal- or moderate-vascularisation. References Cook, et al . Clin J Sport Med. 2004;14:296–299 Hoksrud, et al . Am J Sports Med. 2009;36:1813–1820

Introduction Shoulder impingement syndrome (SIS) is the mechanical entrapment of the supraspinatus tendon underneath the acromial arch of scapula. The narrowing of the subacromial space (SAS) was believed as one of the main contributing factors of SIS. Scapular muscles deficit is believed to cause abnormal scapular kinematics leading to the narrowing of subacromial space and SIS. This study aimed to compare the change of subacromial space during arm elevation between athletes of overhead sports with and without SIS; and its association with scapular muscle strengths. Methods Seventy-two athletes participating in volleyball and baseball (mean age=22.3 ± 3.6) were tested and among them, 39 had SIS. An Aixplorer ® ultrasound machine (SuperSonic Imagine, Aix-en-Provence, France) was used to measure the subacromial space (SAS) during arm at rest, at 30° and 60° of shoulder abduction. Isometric strengths of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) were measured by microFET2 Digital Handheld Dynamometry (Cools, 2010). SAS was defined as the tangential distance between the humeral head and the infero-lateral edge of acromion (Figure 1) (Desmeules, 2004). The change of SAS during arm abduction from 0° to 30° (SAS 0°-30° ), 30° to 60° (SAS 30°-60° ), and 0° to 60° (SAS 0°-60° ) were calculated. Results Our findings revealed significant reduction of SAS during arm abduction from 0° to 60° (p = 0.000) (Figure 2). The changes in SAS 0°-30° was greater in athletes with SIS (0.35 ± 1.12 mm) than healthy athletes (-0.06 ± 1.41 mm) (p = 0.033) (Table 1). Besides, athletes with SIS had significantly decreased scapular strengths (UT, MT, LT and SA) than their healthy counterparts (all p 0°-30° (r=-0.445, p = 0.016 and -0.423, p = 0.022; respectively). Such relationship could not be detected in athletes with SIS. Discussion Our findings demonstrated greater reduction in the subacromial space in early abduction in volleyball and baseball players with SIS than healthy control. The middle and lower trapezius muscles are the scapular muscles associated with the change in the subacromial space in the healthy players. References Cools et al . Br J Sports Med. 2010;44(9):678–684 Desmeules et al . Clin J Sport Med. 2004;14(4):197–205

XVII the Conference in Postural and Gait Research, Marseille, France, 29 May 2005-2 Jun 2005

Background: Until recently it has not been possible to isolate the mechanical behavior of individual muscles during passive stretching. Muscle shear modulus (an index of muscle stiffness) measured using ultrasound shear wave elastography can be used to estimate changes in stiffness of an individual muscle. The aims of the present study were (1) to determine the shear modulus–knee angle relationship and the slack angle of the vastus medialis oblique (VMO), rectus femoris (RF), and vastus lateralis (VL) muscles; (2) to determine whether this differs between the muscles. Methods: Nine male rowers took part in the study. The shear modulus of VMO, RF, and VL muscles was measured while the quadriceps was passively stretched at 3°/s. The relationship between the muscle shear modulus and knee angle was plotted as shear modulus–knee angle curve through which the slack angle of each muscle was determined. Results: The shear modulus of RF was higher than that of VMO and VL when the muscles were stretched over 54° (all p 0.05). The slack angle was similar among the muscles: 41.3° ± 10.6°, 44.3° ± 9.1°, and 44.3° ± 5.6° of knee flexion for VMO, RF, and VL, respectively (p = 0.626). Conclusion: This is the first study to experimentally determine the muscle mechanical behavior of individual heads of the quadriceps during passive stretching. Different pattern of passive tension was observed between mono- and bi-articular muscles. Further research is needed to determine whether changes in muscle stiffness are muscle-specific in pathological conditions or after interventions such as stretching protocols. Keywords: Muscle tension, Optimal length, Shear modulus, Slack angle, Stretch, Ultrasonography, Vastus lateralis, Vastus medialis