Shoulder Joint Position Sense Research Articles

THE EFFECT OF TRUNK STABILITY TRAINING ON UPPER EXTREMITY ENDURANCE, STABILITY AND SHOULDER JOINT PROPRIOCEPTION IN POSTMENOPAUSAL WOMEN

Purpose: The incidence of shoulder pathologies is increasing in postmenopausal women. In this period, there is a need for protective approaches to be applied to prevent shoulder injuries. The aim of this study is to investigate the effects of clinical pilates exercises on upper extremity stability, endurance, function and shoulder joint proprioception in postmenopausal women. Methods: 30 postmenopausal women between the ages of 40-60 were included in our study. Participants were given clinical pilates training for 6 weeks, 3 days a week, 60 minutes by a physiotherapist. Before and after pilates training, dynamic stability of the shoulder was evaluated with Closed Kinetic Chain Upper Extremity Stability Test (CKCUES Test) and Upper Quarter Y Balance Test (UQYBT). Upper extremity muscle endurance was evaluated with the modified push up test. Laser Pointer-Assisted Angle Reproduction Test (LP-ART) was used to evaluate shoulder joint position sense. Results: A statistically significant difference was found in CKCUES Test (p=0.000, r=0.594), UQYBT (p=0.000, r=0.537), modified push up (p=0.000, r=0.594), LP-ART abduction (p=0.000, r= 0.491) and LP-ART flexion (p=0.000, r=0.484) at end of the training compared to the pre-training. The exercise program was found to be highly effective on all parameters. Conclusion: It was concluded that clinical pilates training applied in postmenopausal women increased the dynamic stability of the shoulder, endurance and position sense. Trunk stabilization exercises may be beneficial as a preventive approach in the prevention of shoulder pathologies in postmenopausal women.

Assessing the contribution of different upper limb degrees of freedom to an unconstrained shoulder proprioception task

For the purpose of testing shoulder joint proprioception while controlling for axioscapular muscle recruitment, a novel shoulder thoracohumeral (TH) rotation joint position sense (JPS) measurement device was designed. This device was intended to measure shoulder TH rotation, while also implicitly constraining other upper limb degrees of freedom (DOF) and minimizing cutaneous sensation. The purpose of this study was to determine whether joint motion aside from shoulder TH rotation is being captured by the shoulder JPS measurement device. Upper limb kinematics were collected from 32 participants during joint angle matching trials using the shoulder JPS measurement device. Step wise multiple regression revealed that shoulder TH rotation (β-Humeral Rotation = 0.409, p < 0.001), and wrist deviation (β-Wrist Deviation = 0.104, p = 0.008) both contributed a significant unique variance in the prediction of shoulder JPS measurement device rotation. Findings suggest that seated, unconstrained shoulder TH rotation JPS testing protocols in literature may be confounded by contributions from joints both proximal and distal to the shoulder. Researchers should be aware of the limitations of both constrained and unconstrained shoulder TH rotation JPS testing protocols.

The influence of circulating cold water cryotherapy with or without intermittent pneumatic compression on shoulder joint position sense (JPS) in recreationally active adults: A randomized crossover trial

ObjectivesCryotherapy is a widely used intervention in sports settings to facilitate the return of injured athletes to competition, despite a lack of high-quality evidence. Given the possibility cryotherapy may increase the risk of injury, by reducing nerve conduction velocity, muscle force production, and proprioceptive afferent information, further research is needed to evaluate its effects on proprioception, particularly in the shoulder joint, which has the greatest range of motion of any joint in the body, where there is a dearth of studies. MethodsWe conducted a pre-registered, 1:1 block randomized, baseline controlled, double blind (outcome assessor and statistician), crossover trial of cryotherapy without compression and cryotherapy with compression. ResultsAnalysis indicated there were no statistically significant changes in the accuracy of achieving the target angle because of either the cryotherapy or compression intervention. The small effect sizes observed between the groups indicate that cryotherapy is unlikely to have a clinically significant negative impact on shoulder joint position sense. ConclusionConsequently, returning athletes to the field of play after cryotherapy treatment is not expected to pose an increased risk of injury due to proprioceptive deficits. These findings align with the majority of studies investigating the effects of cryotherapy on proprioception. Impact statementThis pre-registered, randomized, crossover trial on the effects of cryotherapy on joint position sense (JPS) in physical therapy and rehabilitation provides valuable insights into a widely used treatment modality. The small effect sizes observed in our study suggest that cryotherapy is unlikely to have a clinically significant negative effect on shoulder JPS. Cryotherapy remains a viable therapeutic option, without concerns for adverse effects or further injury risk, in returning athletes to the field of play.

Impact of Glycemic Control on Shoulder Proprioception in Type 2 Diabetes Mellitus: Mediating the Connection - Insights from a Cross-Sectional Analysis.

Shoulder proprioception is vital and this cross-sectional study investigated the association between glycemic control and shoulder joint proprioception in Type 2 Diabetes Mellitus (T2DM). A total of 120 participants, including 60 with T2DM and 60 healthy individuals, were assessed for shoulder joint position sense (JPS) using a digital inclinometer. The T2DM group exhibited significantly greater mean shoulder joint position errors in flexion (4.32° vs 2.15°), abduction, medial rotation, and lateral rotation compared to the healthy group (p < 0.001). The study found significantly greater shoulder joint position errors in the T2DM group compared to the healthy group, highlighting notable proprioceptive deficits in individuals with T2DM. Additionally, a significant positive correlation was found between HbA1c levels and shoulder joint position errors in the T2DM group, suggesting a link between long-term glycemic control and proprioceptive accuracy. The significant positive correlation between HbA1c levels and shoulder joint position errors suggests that poor glycemic control is associated with impaired proprioception in T2DM patients. This underscores the need for comprehensive management strategies to mitigate proprioceptive deficits and improve the quality of life in individuals with T2DM.

Shoulder proprioception changesin postmastectomy patients: an observational study.

Breast cancer surgery can cause changes in the anatomical structure of the shoulder and in shoulder mobility, leading to the increased possibility of long-term arm morbidity such as lymphedema. This study aims to evaluate the active shoulder joint position sense (AJPS) with and without lymphedema in postmastectomy patients. A total of 66 women, including 22 patients with lymphedema, 22 patients without lymphedema, and 22 healthy controls, were enrolled in the study. Pain severity was evaluated with the Numeric Pain Scale and edema severity was measured with circumferentially at 10cm intervals. The normal range of motion of the shoulder joint was evaluated with the universal goniometer and the AJPS was assessed by active position repetition testing at 55°, 90°, and 125° shoulder flexion targets using the smartphone application "Clinometer." AJPS at 55°, 90°, and 125° shoulder flexion target angles with and without lymphedema were different in all target angles compared to healthy controls (p < 0.01). There was a difference between the absolute error value of AJPS at 55° flexion (p < 0.05), and no difference at 90° and 125° flexion between the with and without lymphedema groups (p > 0.05). This study shows that the AJPS was negatively affected in with and without lymphedema postmastectomy patients compared to healthy controls. This result emphasizes the importance of adding personalized methods for the restoration of joint position sense in addition to rehabilitation programs generally applied to the patient group.

Awareness of Visual Offset Reduces but Does Not Eliminate Joint Repositioning Errors in Virtual Reality

The present study investigated the effect of visual offset (visuo-proprioceptive mismatch) in joint repositioning task in a three-dimensional virtual reality (VR) environment when participants were instructed to ignore vision. Twenty-five physically healthy young individuals performed shoulder joint position sense test. Repositioning accuracy was tested under two visual conditions, accurate and offset visions, and two instructions, no guidance or ignore vision. In accurate vision trials, the virtual hand of the tested limb seen in VR was congruent with where the participant placed their hand. In the offset vision condition, the virtual hand was seen 8° above or below their actual hand in the vertical plane. Repositioning error (i.e. constant error) in offset vision trials was lower when the participants were instructed to ignore vision compared to when no instruction about the visual offset was given (p < 0.001). However, constant error in offset vision trials was larger than accurate vision trials when the participants tried to ignore vision in both visual conditions (p < 0.001). Our results suggest that humans may be able to down-weight vision to some extent by conscious effort, while the influence of vision is difficult to eliminate when vision is present.

Effects of Eccentric Versus Concentric Strengthening in Patients With Subacromial Pain Syndrome: A Randomized Controlled Trial.

Subacromial pain syndrome (SPS) is the most common cause of shoulder pain. Therapeutic exercise is the first-line treatment for SPS; however, the ideal exercise type remains unclear. Here, we compared the effects of eccentric and concentric strengthening in patients with SPS. Adding isolated eccentric strengthening to a multimodal physiotherapy program (MPP) would lead to greater improvements in outcomes compared with either MPP alone or adding isolated concentric strengthening to the MPP. Randomized controlled trial. Level 2. A total of 45 patients were randomized to eccentric strengthening (ESG), concentric strengthening (CSG), and control (CG) groups; all groups received the MPP. The strengthening groups also performed group-specific strengthening. Shoulder pain, abduction and external rotation (ER) strength, joint position sense (JPS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand score were collected at baseline, after 12 weeks of treatment, and at week 24. For CMS, ESG exhibited a greater, but not clinically meaningful, improvement than CSG and CG (P < 0.05). Eccentric abduction strength increased in ESG compared with CG. From baseline to follow-up, abduction strength increased in ESG compared with CSG and CG. Eccentric abduction strength increased in CSG compared with CG. JPS at abduction improved in the ESG compared with CG. Other between-group comparisons were not significant (P > 0.05). In SPS, eccentric strengthening provided added benefits, improving shoulder abduction strength and JPS at abduction, and was superior to concentric strengthening for improving shoulder abduction strength. Neither strengthening approach had an additional effect on shoulder function, pain, ER strength, or rotational JPS. Clinicians could implement eccentric strengthening as a motor control retraining for strength and proprioception gain rather than for pain relief and reducing disability.

Correlation between Thoracic Kyphosis and Shoulder Joint Position Sense among Health Care Workers

Correlation between Thoracic Kyphosis and Shoulder Joint Position Sense among Health Care Workers

Mediating the Connection: The Role of Pain in the Relationship between Shoulder Muscle Strength, Joint Position Sense, and Sub-Acromial Impingement Syndrome

Sub-acromial Impingement Syndrome (SIS) is a prevalent shoulder pathology characterized by pain, muscle weakness, and altered joint position sense (JPS). This prospective study aimed to comprehensively assess the relationship between shoulder muscle strength, JPS, and pain in individuals with SIS. A total of 100 participants, including 50 with SIS and 50 healthy controls, underwent shoulder muscle strength testing and JPS evaluation in various directions (flexion, abduction, medial rotation, and lateral rotation). Pain intensity was quantified using a visual analog scale. Correlation analyses were conducted to explore the associations between muscle strength, JPS, and pain, with Cohen’s d values indicating the effect size. Individuals with SIS exhibited significantly lower shoulder muscle strength and greater JPS errors compared to the healthy controls (p &lt; 0.001, Cohen’s d = 0.51 to 0.84). The results showed strong positive correlations between muscle strength and JPS in all assessed directions (p &lt; 0.001, with r values ranging from 0.35 to 0.62). Mediation analysis revealed that pain partially mediated the relationship between muscle strength and JPS in all directions (p &lt; 0.005). This study highlights the multifaceted nature of SIS, emphasizing the coexistence of muscle weakness, proprioceptive impairments, and pain. The findings underscore the importance of addressing these factors in the comprehensive rehabilitation of individuals with SIS to optimize functional outcomes and enhance their quality of life.

Handball players have superior shoulder proprioception: a prospective controlled study

Proper proprioceptive and neuromuscular control is crucial for the overhead athlete's performance. The aim of the present study was to evaluate the shoulder joint position sense (JPS) levels in overhead throwing athletes. The secondary aim was to confront the proprioceptive abilities with glenohumeral adaptive changes and pathologies among athletes. Ninety professional handball players and 32 healthy volunteers were recruited. JPS levels were measured by an electronic goniometer and expressed as values of an active reproduction of the joint position (ARJP) and as error of ARJP (EARJP) in three different reference positions for each movement (abduction and flexion at 60°/90°/120°; internal (IR) and external rotation (ER) at 30°/45°/60°). Side-to-side differences revealed significantly better values of EARJP for the throwing shoulders in abduction at 90° and 120°, flexion at 90° and 120°, IR at 60° and in ER at 30° and 60° compared to the non-throwing shoulders. Handball players showed significantly better proprioceptive levels in their throwing shoulder compared to the dominant shoulder of the control group in abduction at 90° (p=0.037) and 120° (p=0.001), flexion at 120° (p=0.035), IR at 60° (p=0.045) and in ER at 60° (p=0.012). Handball players present superior shoulder JPS in their dominant throwing shoulder at high range of motion angles when compared to a non-athlete population and to their own non-dominant shoulder.

Is shoulder joint position sense affected in partial and full-thickness supraspinatus tears?

Neuromuscular control is important for joint stabilization. Supraspinatus muscle plays an essential role in the perception of proprioceptive sense. The aim of this study is to investigate active joint position sense (AJPS) both in patients with partial and full-thickness supraspinatus tears and in healthy participants. Twenty patients with partial supraspinatus tears, 20 patients with full-thickness supraspinatus tears, and 20 healthy participants, aged 40-65years, were included in the study. Proprioceptive sense was assessed with AJPS measurement. Absolute error was calculated to evaluate joint position sense. Active joint position sense was decreased in partial and full-thickness tears on both in affected and contralateral shoulders compared to control group (p < 0.05). There was no difference between groups with partial and full-thickness tears on the affected and contralateral shoulders at 40° and 100° elevation (p > 0.05). AJPS was affected after supraspinatus injury. It was seen as proprioceptive deficit in patients with partial and full-thickness tears in both affected and contralateral shoulders.

Risk factors for shoulder injuries in handball: systematic review

BackgroundHandball is a sport with a high number of severe injuries. The shoulder is one of the most commonly injured joints, with an average prevalence of 17–41%.ObjectiveThe primary aim is to identify the most significant risk factors related to shoulder injuries in handball. The secondary aim is to propose recommendations based on the available evidence concerning potential injury prevention strategies.MethodsSystematic searches of PubMed, MEDLINE, CINAHL, Proquest, SPORTDiscus, Web of Science, EMBASE, and Scopus were undertaken for peer reviewed articles published between 15 July 1995 and 15 July 2019. The same search strategy was repeated on 24 April 2022. Prospective cohort studies, written in English and published in a journal with a peer-review process aiming to investigate at least one modifiable or/and a non-modifiable potential risk factor for shoulder injuries, specifically in handball players, were included. Only papers published after 1995 were included. The methodological quality of the eligible studies was assessed using the modified version of the Downs and Black Checklist. The Best Evidence Synthesis (BES) approach was used for synthesizing and reporting the results.Results1849 studies were identified, of which 8 were included. A total of 2536 (males = 1354, females = 1182) participants of which 2522 were handball athletes, were included. Four of the eight studies were rated as high methodological quality studies (> 85%) while the rest were rated as medium (50–85%). The risk factors for shoulder injuries in handball identified in the studies were strength imbalances (n = 6), glenohumeral range of motion (ROM) imbalances (n = 5), scapular dyskinesis (n = 5), incorrect dosage of training load (n = 2), previous injury (n = 1), sex (n = 2), player’s position, school grade, playing level (n = 1), altered shoulder joint position sense (n = 1).ConclusionOverall, from all the risk factors evaluated, there was strong evidence that the weakness of the shoulder external rotator muscles and the female sex increase the probability of shoulder injury in handball athletes. Nevertheless, the evidence for the other risk factors was moderate due to the methodological quality and the limited number of studies.Protocol registration: PROSPERO ID: CRD42020138233.

Reduced shoulder proprioception due to fatigue after repeated handball throws and evaluation of test-retest reliability of a clinical shoulder joint position test.

Proprioception is vital for motor control and can be disturbed, for example, due to fatigue or injury. Clinical feasible, reliable and valid tests of shoulder proprioception are warranted. The aim was to investigate the effects of local fatigue on shoulder proprioception and the reliability of a feasible joint position sense test using an experimental repeated measures design. Forty participants repeated a shoulder joint position sense test to assess test-retest reliability. The test was then utilized on a subgroup of handball players who were subjected to five bouts of a repeated throwing task with the dominant hand. The effect of local fatigue was investigated by comparing the fatigued with the non-fatigued shoulder. There was a significant interaction for the arm × bout (p = 0.028, ηp2 = 0.20) and a significant effect for the arm (p = 0.034, ηp2 = 0.35) with a significant decrease in joint position sense for the throwing arm compared to the non-throwing arm. The intraclass correlation coefficient was 0.78 (95% CI = [0.57; 0.89]). The standard error of measurement between trials was 0.70° (range: 0.57°-0.90°). The results indicate that repeated throwing to fatigue disturbs shoulder joint position sense. Assessment with the modified test showed acceptable reliability and can be a valuable assessment tool in the clinic.

Effects of a Novel Proprioceptive Rehabilitation Device on Shoulder Joint Position Sense, Pain and Function.

Background and Objectives: Shoulder disorders are associated with pain, restricted range of motion and muscular strength, moderate disability and diminished proprioception. This study aimed to compare the effectiveness of an innovative technology-supported and a classical therapist-based proprioceptive training program in addition to conventional physiotherapy, on joint position sense (JPS), pain and function, in individuals with different musculoskeletal shoulder disorders, such as rotator cuff tear, subacromial impingement syndrome and superior labrum anterior and posterior tear. The innovative element of the proprioceptive training programme consists of the use of the Kinesimeter, a device created for both training and assessing shoulder JPS. Materials and Methods: The shoulder JPS test and the DASH outcome questionnaire were applied to fifty-five individuals (28 females, 27 males, mean age 56.31 ± 6.75), divided into three groups: 17 in the conventional physiotherapy group (control group); 19 in the conventional physiotherapy + classical proprioceptive training program group (CPT group); and 19 in the conventional physiotherapy + innovative proprioceptive training program group (KPT group). Assessments were performed before and after a four-week rehabilitation program, with five physiotherapy sessions per week. Results: When baseline and post-intervention results were compared, the value of the shoulder JPS and DASH outcome questionnaire improved significantly for the KPT and CPT groups (all p < 0.001). Both KPT and CPT groups showed statistically significant improvements in JPS, pain and function, compared to the control group which received no proprioceptive training (all p < 0.05). However, the KPT group showed no significant benefits compared to the CPT group. Conclusions: Our findings indicate that using the Kinesimeter device as a novel, innovative proprioceptive training tool has similar effects as the classical proprioceptive training programs among individuals with different non-operated musculoskeletal shoulder disorders such as: rotator cuff tear, subacromial impingement syndrome, and superior labrum anterior and posterior tear.

The Impact of OKC Exercises and TRX Exercises on Shoulder Joint Proprioception in Overhead Athletes With Shoulder Impingement Syndrome: A Randomized Controlled Trial

Purpose: Sub-acromial impingement syndrome (SAIS) is one of the most common causes of shoulder pain and affects shoulder joint proprioception. The closed kinetic chain (CKC) exercises with sling are more effective and safer than open kinetic chain (OKC) exercises. This study aimed to compare the effectiveness of OKC and total-body resistance exercises (TRX) sling training on shoulder joint position sense (JPS) in overhead athletes with shoulder impingement syndrome (SIS). Methods: This article was a randomized control trial (RCT) study conducted in Kerman City, Iran, in 2019. The research sample included 33 overhead athletes with SIS who were randomly classified into three groups: OKC, sling, and control groups. Joint position sense (JPS) was evaluated in external rotation (ER), internal rotation (IR), and abduction of the dominant arm in the target angle concerning the shoulder range of motion with the Leighton flexometer. The obtained data were analyzed using the analysis of covariance (ANCOVA). Results: The post-intervention results showed that a significant difference was observed between groups (ER, P&lt;0.001; IR, P&lt;0.001; abduction P&lt;0.001). The change in the sling exercises group was significantly higher in ER, and IR, except abduction JPS than in OKC (P=0.001, P=0.001, P=0.235, respectively) and control groups (P&lt;0.001, P&lt;0.001, P&lt;0.001, respectively). Change in the OKC group was significantly higher in ER, IR, and abduction JPS (P=0.001, P=0.019, P&lt;0.001, respectively) than in the control group. The OKC and sling exercise improved the shoulder JPS of overhead athletes with SIS. Conclusion: The study results showed that the sling exercises were more effective than the OKC exercise for the shoulder JPS because these exercises were CKC and performed on an unstable level.

Effects of Adding Aquatic-to-Land-Based Physiotherapy Programs for Shoulder Joint Position Sense Rehabilitation.

There is limited evidence regarding the effects of aquatic-based physiotherapy on shoulder proprioception following post-traumatic injury to the joint. The main aim of this study was to investigate the effects of additional aquatic-based rehabilitation to a land-based physiotherapy program on shoulder joint position sense (JPS) rehabilitation. Forty-four individuals (mean age 44.50 ± 10.11) who had suffered a post-traumatic shoulder injury less than five months previously were pseudo-randomly allocated equally into a control group (9 females, 13 males) and experimental group (6 females, 16 males). Both groups received individualized standard land-based physiotherapy on average for 50 min per session, with five sessions per week for four consecutive weeks. The experimental group received an additional 30 min of personalized aquatic-based therapy during each session. Shoulder JPS was assessed by flexion (60°), extension (25°), abduction (60°), internal rotation (35°) and external rotation (35°) positions prior, halfway through, and after the intervention. Shoulder JPS improved significantly for all positions for both the control group (p < 0.03) and the experimental group (p < 0.01). No significant differences between the control group and the experimental group were found for change in shoulder JPS over time. Our results indicate that shoulder JPS can be significantly improved among individuals with post-traumatic injury to the joint through four weeks of personalized physiotherapy. The addition of aquatic-based exercises to standard land-based therapy did not, however, show significant benefits, and thus cannot be recommended for the improvement of shoulder JPS based on our findings.

Immediate Effects of Flexi-bar Exercise With Knee Push-up Plus on Shoulder Joint Position Sense and Muscle Activity in Subjects With Scapular Winging

Immediate Effects of Flexi-bar Exercise With Knee Push-up Plus on Shoulder Joint Position Sense and Muscle Activity in Subjects With Scapular Winging

Scapular Dyskinesis, Shoulder Joint Position Sense, and Functional Level After Arthroscopic Bankart Repair.

Background:Scapular kinesia is an important component of glenohumeral rhythm and shoulder stability. No studies have evaluated scapular dyskinesis and its relationship to shoulder proprioception in patients who have undergone arthroscopic Bankart repair (ABR).Purpose:To investigate scapular dyskinesis, proprioception, and functional level after ABR.Study Design:Cohort study; Level of evidence, 3.Methods:This study included 13 male patients who underwent ABR (ABR group; mean age, 30 years; range, 24-36 years) and 13 sex- and age-matched healthy individuals (control group). The age, height, weight, and dominant side of all participants were collected. Scapular dyskinesis was evaluated using the lateral scapular slide test and the scapular dyskinesis test; proprioception was measured by the active angle reproduction test using a smartphone goniometer application, and functional level was assessed using the upper-quarter Y-balance test for dynamic stability as well as the Rowe score and Walch-Duplay score for quality of life and return to activities of daily living.Results:The presence of static scapular dyskinesis in the neutral position, at 45° of abduction, and at 90° of abduction as well as the presence of dynamic scapular dyskinesis was higher in the ABR group compared with the control group (P ≤ .04 for all). Shoulder joint position sense (absolute error) at 40° and 100° of shoulder elevation and shoulder functional level according to the Rowe score were worse in the ABR patients compared with the healthy controls (P ≤ .02 for all). Dynamic scapular dyskinesis was negatively related to shoulder joint position sense at 40° of shoulder elevation (r = –0.64; P = .01). Static scapular movement as measured on the lateral scapular slide test was moderately related to the Rowe score (r = 0.58; P = .03).Conclusion:Scapular kinematics and proprioception should be evaluated after ABR. Treatment approaches to improve scapular control and proprioceptive sense should be included in the rehabilitation program for patients after ABR.

The effect of a shoulder injury prevention programme on proprioception and dynamic stability of young volleyball players; a randomized controlled trial

BackgroundThe “FIFA 11 + Shoulder” programme has been reported to reduce the incidence of upper extremity injuries among soccer goalkeepers. It has also been recommended for overhead sports. The purpose of this study was therefore to investigate the effect of an 8-week “FIFA 11 + shoulder” (11 + S) programme on shoulder joint position sense (JPS), threshold to detect passive motion (TTDPM) and upper quarter Y Balance Test in young male volleyball players.MethodsThirty-two healthy young elite male volleyball players (17.49 ± 1.47 years) participated in this quasi-experimental study. Participants, recruited from two clubs participating in Iranian premier league, were randomly assigned into two groups; (1) the intervention group who performed the “FIFA 11 + shoulder” programme as their warm up protocol, three times per week, and (2) the control group who kept their routine warm up protocol meanwhile. Proprioception tests including JPS and TTDPM of internal and external rotator muscles of the dominant shoulder were recorded via the isokinetic system pro 4. The upper quarter Y Balance Test determined the shoulder dynamic stability.ResultsNo statistically significant differences were observed for JPS and TTDPM of shoulder internal and external rotator muscles; shoulder stability however significantly increased only in the intervention group (p = 0.03, ηp2=0.02).ConclusionUpper quarter dynamic stability improvement due to the 11+S programme leads to volleyball players’ performance and may therefore contribute to a reduction in risk of sustaining injury if applied long-term.Trial registrationThe trial was retrospectively registered atIranian Registry of Clinical Trials with the number of IRCT20201030049193N1 at 04/12/2020.

Analysis of factors related to shoulder instability in young handball players

Introduction The shoulder of handball players suffers from the ongoing repetition of movement that may lead to the development of joint instability and modification of proprioceptive condition [1]. Because the articular components of the shoulder joint are considered to have extreme importance on the static and dynamic stabilisation and quality of proprioceptive information, they may compromise the athlete’s performance [2]. The purpose of our study was to verify if shoulder strength parameters (SSP) and joint position sense (JPS) of shoulder internal and external rotation may contribute to the development of shoulder instability in handball players. Materials and methods A cross-sectional design was implemented. The sample was composed by eleven handball players of both genders (4 females and 7 males), under 18 years of age, that practiced the sport for at least 3 years. For the data collection, an isokinetic dynamometer (Biodex System 3) was used. The evaluation of SSP was implemented prior to JPS at a speed of 60°|sec (3 reps) and 180°|sec (20 reps) of internal rotation (IR) and external rotation (ER), with the shoulder positioned at 90° of abduction. The JPS was evaluated using active and passive positioning, 6 repetitions each, at 3 given external shoulder rotation amplitudes (20, 35 and 75 degrees). Prior to the data collection, all subjects signed an informed consent. This study follows all the principles of the Declaration of Helsinki. Results For the dominant shoulder, the peak torque (PT) at 60°|sec was 41.4 Nm (±12.2) of ER and 40,6 Nm (±17.5) in IR. For the non-dominant shoulder at 60°|sec, the PT was 34.3 Nm (±10.7) of ER and 42.0 Nm (±2.8) in IR. For the dominant shoulder, the PT at 180°|sec was 37.2 Nm (±12.2) of ER and 37.9 Nm (±15.0) in IR. At the non-dominant shoulder, the PT at 180°|secr was 29.8 Nm (±10.8) of ER and 37.2 Nm (±11.6) in IR. At 60°|sec, the range of motion (ROM) was of 89.6° (±3.2) and at 180°|sec, 88.8° (±0.6). On the dominant shoulder, for the passive positioning, a difference was obtained of 6.7° (±5.8) at 75°, of 1.7° (±2.4) at 35°, and of 0° (±2.3°) at 20°. In the active positioning, a difference was obtained of 1.3° (±3.1) at 75°, of 1.0° (±3.6) at 35°, and 1.2° (±2.7) at 20°. On the non-dominant shoulder, we observed the following results, in the passive positioning, 4.7° (±3.7) at 75°, 1.3° (± 4.1) at 35°, and 0.7° (±3.5) at 20°. Finally, in the active positioning we obtained the following results: 0.5 ± 3.4 (75°), 0.7 ± 2.0 (35°) and 2.7 ± 2.4 (20°). Discussion and conclusions Our preliminary results seem to point out that the dominant shoulder improved JPS when compared to the non-dominant. Additionally, we found that during the active positioning athletes had a greater perception of JPS, in comparison to the passive positioning. These results should help on the development of training protocols in handball, to improve shoulder proprioception and help to reduce the risk of injury. Although the results on SSP were not statistically treated, throughout the study protocol the PT seems to decrease significantly. Further studies should help to confirm our results.