Osgood-Schlatter disease: a 2020 update of a common knee condition in children.

PURPOSE OF REVIEW: Osgood-Schlatter disease (OSD) is one of the most common causes for anterior knee pain in children and adolescents resulting from a traction apophysitis of the tibial tubercle. While a peak in boys aged 12-15 years old was well documented, there seems to be no difference in sex distribution nowadays. This may result from increased participation of young females in high-impact sports. This review provides an up-to-date account on contemporary prophylaxis as well as diagnostic and therapeutic approaches. RECENT FINDINGS: Numerous studies have examined risk factors for OSD. These include body weight, muscle tightness, muscle weakness during knee extension and flexibility of hamstring muscles. In particular, shortening of the rectus femoris may substantially alter biomechanical functions of the knee. Conservative management remains successful in over 90% of patients. However, if disabling symptoms and pain persistent after physeal closure, operative treatment may be necessary. SUMMARY: OSD is a mostly self-limiting apophysitis of the tibial tubercle and the adjacent patella tendon in young active patients with open physis. Prevention strategies include quadriceps and hamstring stretching and therefore should be implemented in everyday practice routines for children who partake in regular sports activities.

The use of stretching devices for treatment of trismus in head and neck cancer patients: a randomized controlled trial.

PURPOSE: To compare the effects of two stretching devices, the TheraBite® Jaw Motion Rehabilitation System™ and the Dynasplint Trismus System®, on maximal mouth opening in head and neck cancer patients. METHODS: Patients were randomly assigned to one of two exercise groups: the TheraBite® Jaw Motion Rehabilitation System™ group or the Dynasplint Trismus System® group. Patients performed stretching exercises for 3 months. During the three study visits, maximal mouth opening was measured and the patients completed questionnaires on mandibular function and quality of life. RESULTS: In our study population (n = 27), five patients did not start the exercise protocol, eight patients discontinued exercises, and two patients were lost to follow-up. No significant differences regarding the change in mouth opening between the two devices were found. Patients had an increase in MMO of 3.0 mm (IQR - 2.0; 4.0) using the TheraBite® Jaw Motion Rehabilitation System™ and 1.5 mm (IQR 1.0; 3.0) using the Dynasplint Trismus System®. Exercising with either stretching device was challenging for the patients due to the intensive exercise protocol, pain during the exercises, fitting problems with the stretching device, and overall deterioration of their medical condition. CONCLUSIONS: The effects of the two stretching devices did not differ significantly in our study population. The factors described, influencing the progression of stretching exercises, need to be taken into account when prescribing a similar stretching regimen for trismus in head and neck cancer patients. TRIAL REGISTRATION: NTR - Dutch Trial Register number: 5589.

Compression of Myofascial Trigger Points With a Foam Roller or Ball for Exercise-induced Anterior Knee Pain: A Randomized Controlled Trial.

OBJECTIVE: The study aimed to evaluate the effectiveness of compression of myofascial trigger points (MTrPs) with a foam roller or ball, combined with static stretching of knee muscles, on exercise-induced, anterior knee pain in fitness runners. DESIGN: The research team designed a randomized controlled trial. SETTING: The study took place in the Department of Sports Medicine and Rehabilitation Center of the School of Kinesiology at Shanghai University of Sport in Shanghai, China. PARTICIPANTS: A total of 80 participants, 28 males and 52 females with an average age of 37.2 ± 2.9 years, were recruited at the center. INTERVENTION: The participants were randomly assigned to one of 4 groups, with 20 participants in each group: (1) the MG+SG group, which received compression with a foam roller or ball (MG) and static stretching (SG); (2) the MG group, which received compression only; (3) the SG group static, which received static stretching only; or (4) the control group (CG), which attended a 30-min class about nutrition or exercise once a month and received no intervention. For the MG intervention, participants' MTrPs were compressed with a foam roller or ball for 30 minutes once every 5 days for 2 months. After each compression, the MG+SG group received static stretching immediately. OUTCOME MEASURES: A visual analog scale (VAS) and a participant's range of motion (ROM) of the knee were assessed at baseline, after 4 weeks of the intervention, immediately postintervention, and at a follow-up at 8 weeks postintervention. The effectiveness of the treatment in the different groups was also compared. RESULTS: Immediately postintervention, 18 participants (90%) in MG+SG group, 12 (60%) in MG group, and 8 (40%) in the SG group were pain free. Compared with those at baseline, the VAS scores of the MG+SG group significantly improved between baseline and postintervention and were unchanged at the eight-week follow-up. In all groups, the VAS scores and ROMs of the knee increased, but only the MG+SG group's values increased significantly. CONCLUSIONS: Compression of MTrPs with a foam roller or ball, combined with static stretching, was more effective than either the compression only or static stretching only.

Comparative efficacy of active recovery and cold water immersion as post-match recovery interventions in elite youth soccer.

The current study compared cold-water immersion (CWI) and active recovery (AR) to static stretching (SS) on muscle recovery post-competitive soccer matches in elite youth players (n = 15). In a controlled crossover design, participants played a total of nine competitive soccer games, comprising three 80 minute games for each intervention (SS, CWI and AR). Muscle oedema, creatine kinase (CK), countermovement jump performance (CMJA) and perceived muscle soreness (PMS) were assessed pre-, immediately post-, and 48 hours post-match and compared across time-intervals and between interventions. Following SS, all markers of muscle damage remained significantly elevated (P < 0.05) compared to baseline at 48 hours post-match. Following AR and CWI, CMJA returned to baseline at 48 hours post-match, whilst CK returned to baseline following CWI at 48 hours post-match only. Analysis between recovery interventions revealed a significant improvement in PMS (P < 0.05) at 48 hours post-match when comparing AR and CWI to SS, with no significant differences between AR and CWI observed (P > 0.05). Analysis of %change for CK and CMJA revealed significant improvements for AR and CWI compared to SS. The present study indicated both AR and CWI are beneficial recovery interventions for elite young soccer players following competitive soccer matches, of which were superior to SS.

Randomized Controlled Trial of A 12-Week Yoga-Based (Including Diet) Lifestyle vs. Dietary Intervention on Cardio-Metabolic Risk Factors and Continuous Risk Score in Indian Adults with Metabolic Syndrome.

Metabolic syndrome, a prediabetic and precardiovascular pathologic condition that begins early in life, tracks into adulthood and magnifies with age. Randomized controlled trials evaluating efficacy of yoga-based lifestyle vs. dietary intervention on metabolic syndrome are lacking. Here, the efficacy of a 12-week yoga-based lifestyle intervention vs. dietary intervention on cardio-metabolic risk factors and metabolic syndrome risk scores have been assessed in Indian adults with metabolic syndrome. In this two-arm, open label, parallel group, randomized controlled trial, 260 adults (20-45 years) diagnosed with metabolic syndrome as per joint interim statement, 2009 were randomized to yoga-based (including diet) lifestyle or dietary intervention alone (n = 130, each) for 12 weeks. Primary endpoints were the 12-week changes in cardio-metabolic risk factors and metabolic risk scores. The secondary endpoints were the 12-week changes in the proportion of subjects recovered from metabolic syndrome, dietary intake, and physical activity. Intent-to-treat analysis was performed including all the subjects with baseline data with imputed missing data. Treatment × time interaction showed yoga-based lifestyle intervention had a greater treatment effect over dietary intervention by significantly reducing waist circumference, continuous metabolic syndrome z-score, and dietary intake/day while significantly increasing physical activity. High-density lipoprotein cholesterol showed a significantly greater reduction following dietary intervention than yoga-based lifestyle intervention. A significantly greater proportion of subjects recovered from metabolic syndrome in yoga-based lifestyle (45.4%) vs. dietary intervention group (32.3%). A 12-week yoga-based lifestyle intervention is more efficacious than usual dietary intervention in improving cardio-metabolic risk factor and metabolic risk score in Indian adults with metabolic syndrome.

Effects of Combining Running and Practical Duration Stretching on Proprioceptive Skills of National Sprinters.

Romero-Franco, N, Párraga-Montilla, JA, Molina-Flores, EM, and Jiménez-Reyes, P. Effects of combining running and practical duration stretching on proprioceptive skills of national sprinters. J Strength Cond Res 34(4): 1158-1165, 2020-Practical duration stretching after aerobic activities is a recommended component of the first part of warm-up because of its effects on performance. However, its effects on proprioceptive skills are unknown. This study aimed to analyze the effects of running and practical duration static stretching (SS) and dynamic stretching (DS) on postural balance and the joint position sense (JPS) of national sprinters. Thirty-two national sprinters were randomly classified into a SS group (n = 11), DS group (n = 11), or control group (n = 10). Static stretching performed 5 minutes of running and short-duration (20 seconds) static stretches; DS performed 5 minutes of running and short-duration dynamic (20 seconds) stretches; and the control group performed 5 minutes of running. Before and after the intervention, unipedal static postural balance and knee JPS were evaluated. Static stretching exhibited a more centralized center of pressure in the medial-lateral plane for unipedal static postural balance in right-leg support after stretching (p = 0.005, d = 1.24), whereas DS showed values further from the center after stretching for the same unipedal support compared with baseline (p = 0.042, d = 0.49), and the control group remained stable (p > 0.05). Joint position sense did not show significant differences in any group (p > 0.05). In conclusion, combining running and practical duration SS may be beneficial for right-leg postural stabilization, whereas DS may be partly and slightly deleterious. Both SS and DS combined with running and running alone have neutral effects on knee JPS. Sports professionals should consider running and practical duration SS as part of the warm-up of sprinters to partly improve unipedal static postural balance.

Chronic Effects of Static and Dynamic Stretching on Hamstrings Eccentric Strength and Functional Performance: A Randomized Controlled Trial.

Barbosa, GM, Trajano, GS, Dantas, GAF, Silva, BR, and Vieira, WHB. Chronic effects of static and dynamic stretching on hamstrings eccentric strength and functional performance: A randomized controlled trial. J Strength Cond Res 34(7): 2031-2039, 2020-The purpose of this study was to investigate the effect of static or dynamic stretching training program on hamstrings eccentric peak torque and functional performance. Forty-five active healthy men were randomly allocated into 3 groups (n = 15 per group): no stretching (control), static stretching (3 sets of 30 seconds), and dynamic stretching (3 sets of 30 repetitions). Static and dynamic stretching protocols on the hamstring muscles were performed 3 times a week until complete 10 sessions. Isokinetic knee flexor eccentric peak torque (60°·s), triple hop distance, and modified 20-m sprint time were assessed in a random order before and after stretching training. A mixed-design analysis of variance was performed, with an alpha level of 0.05. There was a significant decrease of eccentric peak torque (p ≤ 0.0001, -15.4 ± 10.4%, within-group effect size: 1.03) after static stretching training. The static stretching training reduced eccentric torque when compared with no stretching (-7.6 ± 21.7%, between-group effect size: 0.50) and dynamic stretching (-7.8 ± 29.8%, between-group effect size: 0.51). Moreover, the reached distance on triple hop test was also reduced after static stretching protocol (p = 0.009, -3.7 ± 4.1%, within-group effect size: 0.29). These findings suggest that static stretching training is sufficient to produce meaningful reductions on hamstrings eccentric torque and functional performance. Based on the results of this study, caution should be taken when prescribing of static stretching training in isolation when the purpose is to improve performance, and indirectly, to prevent hamstring strain injuries due to its possible negative effects on hopping performance and knee flexor eccentric torque.

Effect of a Hamstring Flexibility Program Performed Concurrently During an Elite Canoeist Competition Season.

Álvarez-Yates, T and García-García, O. Effect of a hamstring flexibility program performed concurrently during an elite canoeist competition season. J Strength Cond Res 34(3): 838-846, 2020-The aim of this study was to determine the acute effect of an 8-week specific hamstring flexibility training on junior canoeist during the competition season. Sixteen canoeists participated, divided into 3 groups: 5 in experimental group 1 (EG1), 5 in experimental group 2 (EG2), and 6 in a control group. The EG1 underwent a supervised program consisted by simple static stretching, dynamic static stretching, and proprioceptive neuromuscular facilitation (PNF), whereas the EG2 performed a program without PNF and no supervision. Two measurements were performed to analyze the effect on the knee joint range of motion (ROM) and trunk flexion; neuromuscular and contractile properties in biceps femoris (BF) and semitendinosus (ST) muscles; and maximum power and average speed in lower limbs. A mixed-design factorial analysis of variance (p ≤ 0.05) was performed and the effect size was calculated. The results show significant improvements (p ≤ 0.05) in both legs for knee joint ROM and trunk flexion in EG1 (8.9 and 25.5%; 5.7 and 20.9% in the right and left leg, respectively) and EG2 (6.7 and 22%; 3.9 and 24.4%), only EG1 improved muscular stiffness in BF (27.4% left leg) and ST (20.5 and 24.3%), and lateral symmetry in BF (49%) without decreasing average speed in lower limbs. All improvements have a large effect size. In conclusion, it is suggested that a supervised hamstring flexibility program performed concurrently during a canoeist competition season can produce an increase in the knee joint ROM and trunk flexion, without negative repercussions in contractile and neuromuscular capacities, maximum power, and average velocity in lower limbs.

Immediate Effects of Intermittent Bilateral Ankle Plantar Flexors Static Stretching on Balance and Plantar Pressures.

OBJECTIVE: The purpose of this study was to analyze the immediate effects of an intermittent plantar flexion static-stretching protocol on balance and plantar pressures. METHODS: The study included a sample size of 24 healthy participants (21 female and 3 male). Participants were 32.20 ± 8.08 years, 166.20 ± 8.43 cm, and 62.77 ± 9.52 kg. All participants performed an intermittent plantar flexion static-stretching protocol. Five sets (60 seconds intermittent stretch; 15 seconds for the rest time) of a passive plantar flexor stretching (70% to 90% of the point of discomfort) were performed. Static footprint analysis and a stabilometry analysis were performed before and after stretching. A P value < .05 with a CI of 95% was considered statistically significant for all tests. RESULTS: Intermittent ankle plantar static stretching resulted in a significantly greater forefoot surface contact area and lower rear foot medium and maximum plantar pressures. In addition, static stretching caused a lower displacement of the center of pressure for both eyes open and eyes closed conditions. CONCLUSION: An intermittent plantar flexor static-stretching protocol improved balance and reduced rear foot plantar pressures (maximum and medium pressures).

Exercise and Parkinson Disease: Comparing Tango, Treadmill, and Stretching.

BACKGROUND AND PURPOSE: Impaired gait, balance, and motor function are common in Parkinson disease (PD) and may lead to falls and injuries. Different forms of exercise improve motor function in persons with PD, but determining which form of exercise is most effective requires a direct comparison of various approaches. In this prospective, controlled trial, we evaluated the impact of tango, treadmill walking, and stretching on gait, balance, motor function, and quality of life. We hypothesized tango and treadmill would improve forward walking and motor symptom severity, and tango would also improve backward walking, balance, and quality of life. METHODS: Ninety-six participants (age: 67.2 ± 8.9 years, 42% female) with mild to moderate idiopathic PD were serially assigned to tango, treadmill walking, or stretching (active control group) and attended 1-hour classes twice weekly for 12 weeks. Assessments occurred OFF anti-PD medication before and after the intervention and at follow-up 12 weeks after the intervention. RESULTS: Forward velocity and backward velocity improved for the treadmill group from baseline to posttest and improvements persisted at follow-up. Backward velocity and motor functioning improved for the stretching group from baseline to posttest, but results did not persist at follow-up. There were no significant changes in the tango group across time points. DISCUSSION AND CONCLUSIONS: Contrary to our hypotheses, only treadmill improved forward walking, while backward walking improved with treadmill and stretching. Future research should examine combinations of exercises with a focus on optimizing dosing and examining whether specific characteristics of people with PD correlate with different types of exercise.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A237).

Effectiveness of Slump Stretching on Low Back Pain: A Systematic Review and Meta-analysis.

BACKGROUND: The slump test is a type of neurodynamic test that is believed to evaluate the mechanosensitivity of the neuromeningeal structures within the vertebral canal. The objective of this review was to investigate the effectiveness of slump stretching on back pain and disability in patients with low back pain (LBP). METHODS: We searched eight electronic databases (PubMed/Medline, Scopus, Ovid, CINAHL, Embase, PEDro, Google Scholar, CENTRAL). The publication language was restricted to English, and we searched the full time period available for each database, up to October 2017. Our primary outcomes were pain and disability, and the secondary outcome was range of motion (ROM). RESULTS: We identified 12 eligible studies with 515 LBP patients. All included studies reported short-term follow-up. A large effect size (standardized mean difference [SMD] = -2.15, 95% confidence interval [CI] = -3.35 to -0.95) and significant effect were determined, favoring the use of slump stretching to decrease pain in patients with LBP. In addition, large effect sizes and significant results were also found for the effect of slump stretching on disability improvement (SMD = -8.03, 95% CI = -11.59 to -4.47) in the LBP population. A qualitative synthesis of results showed that slump stretching can significantly increase straight leg raise and active knee extension ROM. CONCLUSIONS: There is very low to moderate quality of evidence that slump stretching may have positive effects on pain in people with LBP. However, the quality of evidence for the benefits of slump stretching on disability was very low. Finally, it appears that patients with nonradicular LBP may benefit most from slump stretching compared with other types of LBP.

Effects of perineal preparation techniques on tissue extensibility and muscle strength: a pilot study.

INTRODUCTION AND HYPOTHESIS: Perineal preparation techniques for childbirth have been used with the aim of reducing perineal tears during the expulsive phase of labor. However, no studies were found to investigate the effects of instrument-assisted stretching versus perineal massage on pelvic floor muscle (PFM) variables. Therefore, the aim of this study was to evaluate the effect of instrument-assisted stretching versus perineal massage on the extensibility and strength of the PFMs. METHODS: Primiparous women were randomized to the instrument-assisted stretching (IStr) group (n = 13) and perineal massage (PnM) group (n = 14). The groups participated in eight sessions, twice weekly, beginning at the 34th gestational week. The IStr group underwent the intervention for 15 min using EPI-NO®. The PnM group underwent a perineal massage protocol for 10 min. Each woman was evaluated by a blinded physiotherapist before, after four and after eight sessions for primary (PFM extensibility using the EPI-NO® circumference) and secondary (PFM strength using a manometer) outcomes. Covariate analysis (ANCOVA) was used to compare the groups using the baseline values as a covariate. RESULTS: Both groups showed an increase in PFM extensibility compared with the evaluations before and after four and eight sessions (PnM group from 17.6 ± 1.8 to 20.2 ± 1.9 cm; IStr group from 19.9 ± 1.6 to 22.9 ± 1.6 cm;p < 0.001). There was no difference between groups. Regarding muscle strength, no statistical differences were observed between evaluations or between groups. CONCLUSIONS: Instrument-assisted stretching and perineal massage increase extensibility and do not alter the strength of PFMs in pregnant women.

Effect of Creative Dance on Fitness, Functional Balance, and Mobility Control in the Elderly.

BACKGROUND: In the literature on creativity in older adults, creative activities have been found to be an effective way of adapting to age-related psychological and physical changes, providing older adults with opportunities to think differently and be open to new ideas. On the other hand, physical activities play an important role in the prevention of physical decline. Thus, combining physical activity and certain creative activities, such as creative dance (CD), might help facilitate successful aging. Since the National Dance Association has expanded dance into educational and community facilities, CD programs have begun to be developed and widely used for all ages. OBJECTIVE: We investigated the effects of a CD program on fitness, functional balance, and mobility in the elderly. METHODS: Eighty-two community-dwelling older adults were randomly allocated to either a dance group (n = 41, age = 70.5 ± 7.89 years) or a stretching group (n = 41, age = 71.77 ± 7.78 years). Over 8 weeks, these groups participated in CD and stretching training (ST) classes, respectively, which lasted for 90 min and were held 2 days a week. The CD included tasks to explore movement elements (i.e., body, space, time, force), develop their own movement, and transform feelings or inner experiences into movement. The ST included several upper- and lower-body stretching poses. The outcome measures included the Senior Fitness Test (SFT), Berg Balance Scale (BBS), Timed Up and Go Test (TUG), Dynamic Gait Index (DGI), and 10-Meter Walking Test (gait speed). RESULTS: A significant group × time interaction was found for the 30-s stand and 30-s arm curl, and for the BBS, TUG, DGI, and gait speed. Post hoc paired t tests revealed significantly increased scores for the 30-s stand, 30-s arm curl, back stretching, and chair sit and reach tests, and for the TUG, BBS, TUG, DGI, and gait speed in the CD group. The 30-s arm curl and chair sit and reach test scores significantly increased in the ST group. CONCLUSION: CD and stretching may both benefit fitness and balance for older adults; however, CD may improve dynamic balance and mobility more than stretching. Therefore, CD may be a creative physical activity that contributes to successful aging.

Which method for frozen shoulder mobilization: manual posterior capsule stretching or scapular mobilization?

OBJECTIVES: This study aimed to compare the superiority of scapular mobilization, manual capsule stretching, and the combination of these two techniques in the treatment of frozen shoulder patients to evaluate the acute effects of these techniques on shoulder movements. METHODS: This study designed to a single-blinded, randomized, and pre-post assessment study. This study was included 54 patients diagnosed with stage 3 frozen shoulder. Group 1 (n=27) received scapular mobilization, and Group 2 (n=27) received manual posterior capsule stretching. After the patients were assessed, the interventions were re-applied with a crossover design to obtain results for the combined application (n=54). The range of motion, active total elevation, active internal rotation, and posterior capsule tensions of the shoulder joint were recorded before and immediately after mobilization. RESULTS: Statistical analysis showed an increase in all range of motion values (p<0.05), except for shoulder internal rotation (p>0.05), without significant difference among the groups (p>0.05). The posterior capsule flexibility did not change in any group (p>0.05). CONCLUSIONS: Scapular mobilization and manual posterior capsule interventions were effective in improving the acute joint range of motion in frozen shoulder patients.

Robotic-Assisted Shoulder Rehabilitation Therapy Effectively Improved Poststroke Hemiplegic Shoulder Pain: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to investigate the therapeutic effects of a newly developed shoulder robot on poststroke hemiplegic shoulder pain. DESIGN: Prospective, single-blind randomized controlled trial. SETTING: Inpatient department of a tertiary university hospital. PARTICIPANTS: Hemiplegic shoulder pain patients (N=38) were consecutively recruited and randomly assigned to an intervention or control group. INTERVENTIONS: A newly developed robot was designed to perform joint mobilization and stretching exercises with patients lying in the supine position. Conventional physical therapy directed at both improving upper extremity mechanics and reducing neurologic injury was performed twice per day in both groups. In the intervention group, additional robotic-assisted shoulder rehabilitation therapy was administered for 30 minutes per day, 5 times per week for 4 weeks. MAIN OUTCOME MEASURES: The visual analog scale was the primary outcome, and the pain-free passive range of motion of the shoulder joint, the Korean version of the Shoulder Disability Questionnaire, and ultrasonographic grades were the secondary outcomes. The outcomes were evaluated at baseline (T0), postintervention (T1), and a 4-week follow-up (T2). RESULTS: Significant time and group interaction effects were found on the visual analog scale, in the abduction passive range of motion, and on the Shoulder Disability Questionnaire (F2,33=16.384, P=.002; F2,33=10.609, P=.012; F2,33=32.650, P=.008, respectively). Significantly higher improvements in these outcome measures were observed in the intervention group than in the control group at T1 after post hoc analysis (P<0.05, all). These improvements were sustained at T2 when the intervention group was compared with the control group (P<.05, all). CONCLUSIONS: A prototype shoulder rehabilitation robot as an adjuvant therapy improves hemiplegic shoulder pain and self-reported shoulder-related disability.

Dynamic stretching is not detrimental to neuromechanical and sensorimotor performance of ankle plantarflexors.

The acute effects of two dynamic stretching (DS) protocols on changes in the ankle range of motion (RoM), neuromechanical, and sensorimotor properties of the plantarflexor muscle group were examined. Eighteen participants received slow (SDS) or fast dynamic stretching (FDS) on two separate days. Outcome measures were assessed pre- and 2 minutes post-interventions, and included maximum dorsiflexion angle, maximum isometric torque at neutral ankle position, maximum concentric and eccentric torques, force matching capacity, joint position sense and medial gastrocnemius muscle and tendon strain. Possibly and likely small increases in dorsiflexion RoM were observed after SDS (mean ± 90% confidence intervals; 1.8 ± 1.2°) and FDS (2.1 ± 1.2°), respectively. Very likely moderate decreases in muscle strain after SDS (-38.0 ± 20.6%) and possibly small decrease after FDS (-13.6 ± 21.2%) were observed. SDS resulted in a likely beneficial small increase in tendon strain (25.3 ± 29.7%) and a likely beneficial moderate increase after FDS (41.4 ± 44.9%). Effects on strength were inconsistent. Possibly small effect on positional error after SDS (-27.1 ± 37.5%), but no clear effect after FDS was observed. Both DS protocols increased RoM, and this was more due to an increase in tendon elongation rather than the muscle. However, SDS showed greater improvement than FDS in both neuromechanical and sensorimotor performance, and hence, SDS can be recommended as part of warm-up in sporting contexts.

A structured exercise programme combined with proprioceptive neuromuscular facilitation stretching or static stretching in posttraumatic stiffness of the elbow: a randomized controlled trial.

OBJECTIVES:: To compare the different stretching techniques, proprioceptive neuromuscular facilitation (PNF) stretching and static stretching, in patients with elbow stiffness after a treated elbow fracture. DESIGN:: Randomized-controlled, single-blind study. SETTING:: Department of physiotherapy and rehabilitation. SUBJECTS:: Forty patients with posttraumatic elbow stiffness (24 women; mean age, 41.34 ± 7.57 years). INTERVENTION:: PNF stretching group ( n = 20), hold-relax PNF stretching combined with a structured exercise programme (two days per week for six weeks); static stretching group ( n = 20), static stretching combined with a structured exercise programme (two days per week for six weeks). MAIN MEASURES:: The primary outcome is the Disabilities of the Arm, Shoulder and Hand (DASH). The secondary outcomes are active range of motion (AROM), visual analogue scale (VAS), Tampa Scale for Kinesiophobia, Short Form-12 and Global Rating of Change. Participants were assessed at baseline, after a six-week intervention period and one-month later (follow-up). RESULTS:: After treatment, improvement in the mean DASH score was slightly better in the PNF stretching group (8.66 ± 6.15) compared with the static stretching group (19.25 ± 10.30) ( p = 0.03). The overall group-by-time interaction for the 2 × 3 mixed-model analysis of covariance (ANCOVA) was also significant for elbow flexion AROM (mean change for PNF stretching group; static stretching group; 41.10, 34.42, p = 0.04), VAS-rest (-1.31, -1.08, p = 0.03) and VAS-activity (-3.78, -3.47, p = 0.01) in favour of PNF stretching group. The other outcomes did not differ significantly between the two groups. CONCLUSION:: The study demonstrated that the structured exercise programme combined with PNF stretching might be effective in patients with posttraumatic elbow stiffness with regard to improving function, elbow flexion AROM, pain at rest and during activity.

The effects of 6 weeks of constant-angle muscle stretching training on flexibility and muscle function in men with limited hamstrings' flexibility.

PURPOSE: The aim of the present study was to evaluate the effects of 6 weeks of a constant-angle hamstring muscle flexibility training on muscle-tendon stiffness and the range of motion (ROM) in young men with limited hamstring ROM. METHODS: 13 participants performed unilateral stretching training (EL), while the contralateral limb acted as control (CL). ROM, relative and peak passive torque, passive stiffness, dynamic knee flexion strength, and active optimum joint angle were assessed before and after the last training session. In addition, participants were tested during the first and last training sessions for first stretch sensation during the stretching procedure only in the EL. RESULTS: Straight-leg raise and isokinetic knee ROM tests (both p < 0.0001; from 59.4 ± 8.1 to 70.3 ± 9.8, from 28.3 ± 7.6 to 18.5 ± 5.2, respectively) and peak passive torque (p = 0.001; from 53.1 ± 11.7 to 64.9 ± 12.3) increased only in EL and no changes in relative passive torque, passive stiffness, dynamic knee flexion strength, and active optimum joint angle (p > 0.05) were observed. At the point of first stretch sensation, significant increases in passive torque (p = 0.004) and angle (p < 0.001) were found from pre- to post-training. CONCLUSION: The flexibility training induced significant increases in ROM alongside increases in peak passive torque (stretch tolerance) and the ROM at which stretch was first perceived. However, this occurred without changes in muscle-tendon mechanical properties or transfer to the untrained limb (CL). These results suggest that limb-specific ROM increases were underpinned by neural adaptations.

Unilateral hamstrings static stretching can impair the affected and contralateral knee extension force but improve unilateral drop jump height.

PURPOSE: Prolonged static stretching (SS) in isolation (no dynamic warm-up) can impair muscle performance. There are conflicting reports whether impairments are present in antagonist and contralateral muscles. The objective of this study was to assess the effect of unilateral hamstrings SS on ipsilateral stretched and contralateral limbs' strength and jump power. METHODS: The SS (four repetitions of 30-s) and control sessions involved unilateral testing of the stretched leg and contralateral leg for knee extension (KE) maximum voluntary isometric contraction (MVIC) force and electromyography (EMG), drop jump (DJ) height and contact time at 1-min post-stretching. RESULTS: There were significant KE MVIC force impairments for both the SS (p = 0.006, d = 0.3, - 8.1%) and contralateral (p = 0.02, d = 0.20, - 4.2%) leg. With normalized data, there was a near-significant (p = 0.1), small magnitude (d = 0.29), greater force impairment with the ipsilateral (93.0 ± 12.8% of pre-test) versus the contralateral (96.2 ± 9.1% of pre-test) KE MVIC force. DJ height significantly improved for the stretched leg (p = 0.03, d = 0.18, + 9.2%) with near-significant, improvements for the contralateral leg (p = 0.06, d = 0.22, + 12.1%). For the stretched leg, DJ contact time was significantly (p = 0.04, d = 0.18, + 3.4%) prolonged, but there was no significant change with the contralateral leg. CONCLUSIONS: Unilateral hamstrings SS induced strength deficits in the ipsilateral and contralateral knee extension MVIC and a prolongation of the stretched leg DJ contact period. In anticipation of maximal force outputs, prolonged SS in isolation (no dynamic warm-up included) can have negative consequences on antagonist and contralateral muscle performance.

Passive muscle stretching impairs rapid force production and neuromuscular function in human plantar flexors.

PURPOSE: We examined the effect of muscle stretching on the ability to produce rapid torque and the mechanisms underpinning the changes. METHODS: Eighteen men performed three conditions: (1) continuous stretch (1 set of 5 min), (2) intermittent stretch (5 sets of 1 min with 15-s inter-stretch interval), and (3) control. Isometric plantar flexor rate of torque development was measured during explosive maximal voluntary contractions (MVC) in the intervals 0-100 ms (RTDV100) and 0-200 ms (RTDV200), and in electrically evoked 0.5-s tetanic contractions (20 Hz, 20 Hz preceded by a doublet and 80 Hz). The rate of EMG rise, electromechanical delay during MVC (EMDV) and during a single twitch contraction (EMDtwitch) were assessed. RESULTS: RTDV200 was decreased (P < 0.05) immediately after continuous (- 15%) and intermittent stretch (- 30%) with no differences between protocols. The rate of torque development during tetanic stimulations was reduced (P < 0.05) immediately after continuous (- 8%) and intermittent stretch (- 10%), when averaged across stimulation frequencies. Lateral gastrocnemius rate of EMG rise was reduced after intermittent stretch (- 27%), and changes in triceps surae rate of EMG rise were correlated with changes in RTDV200 after both continuous (r = 0.64) and intermittent stretch (r = 0.65). EMDV increased immediately (31%) and 15 min (17%) after intermittent stretch and was correlated with changes in RTDV200 (r = - 0.56). EMDtwitch increased immediately after continuous (4%), and immediately (5.4%), 15 min (6.3%), and 30 min after (6.4%) intermittent stretch (P < 0.05). CONCLUSIONS: Reductions in the rate of torque development immediately after stretching were associated with both neural and mechanical mechanisms.