Effect of stretching duration on active and passive range of motion in the lower extremity

OBJECTIVES: To investigate the effect of different durations of stretching (five or 15 seconds) on active and passive range of motion (ROM) in the lower extremity during a five week flexibility training programme. METHOD: Twenty four university sport club members (19 men, five women), with a mean (SD) age of 20.5 (1.35) years, were randomly assigned to one of three groups (two treatment and one control). The two treatment groups participated in a static active stretching programme three times a week for a five week period, holding each stretch for a duration of either five or 15 seconds. The total amount of time spent in a stretched position was controlled. The five second group performed each stretch nine times and the 15 second group three times resulting in a total stretching time of 45 seconds for both groups for each exercise. The control group did not stretch. Active and passive ROM were determined during left hip flexion, left knee flexion, and left knee extension before and after the training programme using an inclinometer. RESULTS: Two factor within subject analysis of variance indicated no significant difference in ROM before and after the training programme for the control group. However, significant improvements in active and passive ROM (p < 0.05) were shown in both treatment groups after the five week training programme. Two factor analysis of variance with repeated measures and post hoc analysis showed significant differences between the treatment groups and the control group for the improvements observed in active (p < 0.05) and passive (p < 0.05) ROM. The five and 15 second treatment groups did not differ from one another when ROM was assessed passively, but significant differences were apparent for active ROM, with the 15 second group showing significantly greater improvements (p < 0.05) than the five second group. CONCLUSION: These findings suggest that holding stretches for 15 seconds, as opposed to five seconds, may result in greater improvements in active ROM. However, sustaining a stretch may not significantly affect the improvements gained in passive ROM.     

Effects of warming up, massage, and stretching on range of motion and muscle strength in the lower extremity

The effects of general warming up, massage, and stretching on ranges of motion (ROM) and strength of quadriceps and hamstring muscles were measured in eight male volunteers. Thigh muscle strength was not influenced by the experimental procedures. Stretching resulted in a significantly increased range of hip flexion/extension, hip abduction, knee flexion, and ankle dorsiflexion; the effect was significantly greater than that obtained by massage and warming up separately or combined. Only ankle dorsiflexion was influenced by massage or warming up, whereas stretching affected all muscle groups tested. Stretching was, therefore, superior to the other methods tested for increasing flexibility in the lower extremity.     

The effect of contralateral training: Influence of unilateral isokinetic exercise on one-legged standing balance of the contralateral lower extremity in adults

Purpose

To investigate the effects of unilateral isokinetic exercises on the one-legged standing balance of the contralateral lower extremity.

Subjects

A volunteer sample of 32 healthy adults (12 men and 20 women) was randomized to training and control groups.

Methods

The training group received unilateral hip isokinetic exercises of the dominant leg for two weeks. Contralateral single-limb balance was measured before and after intervention, including three stability index scores of balance using Biodex Stability System: Anterior-Posterior Stability Index (APSI), Medio-lateral Stability Index (MLSI), and Overall Stability Index (OSI) scores.

Results

Comparison of pre-test and post-test data revealed significant improvements in APSI, MLSI, and OSI scores in the training group (p < 0.05), but not in the control group. The gains of stability scores from pre- to post-test, were also significantly greater (p < 0.05) in the training group than the control group.

Conclusion

These results suggest that contralateral training with unilateral isokinetic exercises increases the one-legged standing balance of the contralateral limb following a short duration of training.     

肌内效贴对高强度训练后下肢训练伤的防护效果

目的 探讨肌内效贴对高强度训练后下肢训练伤的防护效果。方法 2019-06至2019-07从某部集训战士中选取51名受试者,随机分为三组：肌内效贴组(KT组)、安慰剂贴组(PT组)和静态拉伸组(SC组),每组17名。10 km武装奔袭后即刻、24 h、48 h、72 h,比较三组视觉模拟评分(VAS)、膝关节功能(ROM)、Lysholm评分、大腿周径等。结果 在训练后即刻、24 h、48 h、72 h, KT组的VAS值均低于SC组和PT组(P<0.05);KT组在训练后48 h、72 h对ROM的改善明显优于PT组和SC组(P<0.05),训练后48 h的Lysholm评分高于PT组及SC组(P<0.01);SC组在训练后72 h的VAS值低于PT组,对ROM的改善优于PT组(P<0.05)。三组不同时间的大腿周径无统计学差异。结论 肌内效贴有利于高强度训练后缓解下肢肌肉疼痛,增强膝关节稳定性,且能改善关节活动度,可用于下肢军事训练伤的防治。     

The effect of active warm-up and stretching on the flexibility of adolescent soccer players

AIM: The purpose of the investigation was to examine in field conditions the acute effects of passive stretching after a general warming-up bout as well as the effects of passive stretching alone. METHODS: Eighteen adolescent team soccer players participated in this study performing 3 different flexibility-training protocols in separate training sessions. In the first treatment stretching protocol a general warm-up was performed where subjects jogged for 20 minutes. The second treatment stretching protocol consisted of the same general warm-up followed by passive stretching of the lower extremities and the trunk, whereas the third and final treatment stretching protocol consisted of passive stretching alone, without any jogging. Passive range of joint motion was examined in hip flexion, hip extension, hip abduction, ankle dorsiflexion, knee flexion and trunk flexion using a goniometer and a flexometer. RESULTS: The general warming-up session induced a significantly increased range of motion only at the ankle dorsiflexion joint (P<0.05). Results also suggest that passive stretching alone and passive stretching after a general warming-up bout both induced a significantly increased range in all lower extremity joints and trunk flexion (P<0.001). CONCLUSIONS: Improvements in flexibility are observed after passive muscle elongation, irrespective of warming-up.     

Whole-body vibration and stretching enhances dorsiflexion range of motion in individuals with chronic ankle instability

ObjectiveThe purpose of this study was to determine if WBV performed concurrently with static stretching was more effective than static stretching alone to increase dorsiflexion ROM (DFROM) in individuals with chronic ankle instability (CAI).DesignControlled laboratory study.ParticipantsThirty-nine participants with CAI (history of ankle sprain, a feeling of “giving way” during activity, and a qualifying Foot and Ankle Ability Measure Ankle score) were divided into 3 groups (normative (N), static stretch (SS), and static stretch with vibration (SV)). Participants stretched the triceps surae 4 days/wk for 3 wks. Vibration was imposed at 34 Hz and 1.8 mm.Main outcome measuresDFROM was assessed in a straight and bent-leg position.ResultsNo differences were detected at any time in the N or SS group, however SS did exhibit large effect sizes with 95% confidence intervals (CI) that did not cross zero from baseline to 3 weeks for both measures. The SV group demonstrated increased DFROM from baseline for both time points and a large effect size with 95% CI that did not cross zero from post tx-1 to post tx-2.ConclusionsStatic stretching with WBV increases DFROM in participants with CAI more effectively than static stretching alone.     

The effect of leg strength on the incidence of lower extremity overuse injuries during military training

This study examined the effects of strength, aerobic fitness, and activity profile on the incidence of overuse injuries, particularly stress fractures, during military training. A total of 136 military recruits were followed during 9 weeks of basic training. Maximal strength and aerobic fitness were determined by a one-repetition maximum leg press and a 2,000-m run, respectively. An activity profile was determined by the recruit's activity history. Twelve recruits (8.8%) were diagnosed with stress fractures. Recruits who were 1 SD below the population mean in both absolute (98.4 +/- 36.6 kg) and relative strength (1.72 +/- 0.61 kg/kg of body weight) had a five times greater risk for stress fracture (p < 0.05) than stronger recruits. Poor aerobic fitness did not appear to be related to any increased incidence of stress fracture. It appears that recruits with lower body strength levels, within 1 SD of the population mean, have a reduced incidence of stress fractures during military training.     

Effects of intense "stretching"-flexibility training on the mechanical profile of the knee extensors and on the range of motion of the hip joint

The sample for the study involved 12 volunteer male, active but not specially trained secondary school students. They averaged 15.33 years with a mean height of 168.20 cm, and a mean mass of 55.08 kg. Changes, if any, in the mechanical properties (MVC, half-relaxation time, fast isometric contraction, concentric contraction of the knee extensors) and flexibility of the hip joints were studied. The subjects executed passive, purely slow stretching as well as range-of-motion flexibility exercises for the knee extensors and the hip joints for 7 weeks three times a week. Pre- and post-measurements for flexibility and stride frequency on the spot showed significant improvement as did half-relaxation time, fast isometric force development, and speed of concentric contractions when low loads were to be overcome. In addition to studies in which improvements reported were attributed to and related to myoelectrical, reflex, and connective tissue changes, in the present study it was concluded that stretching exercises influence intrinsic muscle mechanical character along with a simultaneous improvement in range of motion of the joints exercised.     

Functional range of motion in the upper extremity and trunk joints: Nine functional everyday tasks with inertial sensors

BackgroundFunctional range of motion is defined as the required range of motions for individuals to maintain maximal independence, along with optimal conditions for activities of daily living. Intervention plans for rehabilitation are directed towards the acquisition of anatomical range of motion. However, this isn’t always possible based on person’s etiology, prognosis, or severity of disease.Research questionThe aim of this study is to determine functional range of motion during different unilateral, bilateral symmetrical and bimanual asymmetrical tasks of activities of daily living.MethodsParticipants completed nine basic activities of daily living (hand to head, hanging jacket, eating, wallet placement to back pocket, washing hands and face, removing belt, water pouring, brushing teeth) linked according to International Classification of Functioning, Disability and Health, while joint kinematics of the trunk and upper extremity were recorded with inertial measurement units. Peak values of mean joint angles were determined for each activities of daily living. MVN BIOMECH Awinda MTW2-3A7G6 sensors (Xsens Technologies B.V. Enschede, Netherlands) were used for 3D kinematic analysis of activities.ResultsForty-six healthy subjects (right-dominant) were included in this study. Range of motion requirements of all activities were defined 37.85° extension, 91.18° flexion, 1.25° adduction, 39.45° abduction, 63.6° internal rotation, 21.8° external rotation in the dominant shoulder, 124.17° flexion in the dominant elbow, 40.29° extension, 23.66° flexion, 18.31° supination, 12.56° pronation, 18.27 ulnar deviation and, 18.36° radial deviation in the dominant wrist. Maximum trunk range of motions were found to be 29.75° flexion in C7-T1, 10.74° flexion in T12-L1, and 24.16° flexion in L5-S1.SignificanceIt is thought that the results of this research will contribute to the determination of normative data needed for surgical interventions, technological rehabilitation devices and task-spesific rehabilitation programs which based patient's motor skill level.     

The effects of proprioceptive neuromuscular facilitation stretching on shoulder range of motion in overhand athletes

AIM: The purpose of this study was to compare the effects of the contract-relax-contract (CRC) and hold-relax-contract (HRC) proprioceptive neuromuscular facilitation (PNF) stretching programs against a control, on external range of motion (ROM) of the shoulder in apparently healthy athletes. METHODS: The subjects were male and female adults between the ages of 25 to 50 years old. Subjects also had been involved in at least one overhand throwing sport (tennis, baseball, quarterback in football, etc.) in the past year. There were 30 participants whom were randomly assigned to 1 of 3 groups (CRC PNF, HRC PNF, control) with 10 subjects per group. Measurement of ROM for external rotation of the shoulder was performed prior to and after 6 weeks of training using a goniometer. The CRC and HRC PNF stretches were performed on subjects twice a week for 6 weeks. The statistical analysis conducted involved a 3x2 analysis of variance with the criteria for statistical significance set at p<0.05. Post hoc testing included paired t-tests and Tukey tests to pinpoint significant differences relative to the interaction between group and time. RESULTS: There was an increase in ROM from pretest to post-test for the HRC group (+13.50 degrees) and CRC group (+14.60 degrees), but not in the control group (+0.30 degrees). The improvement in ROM however, was similar between the HRC and CRC groups. CONCLUSIONS: The CRC and HRC PNF stretching techniques are effective at increasing external shoulder ROM when consistently performed 2 times a week for 6 weeks.     

The effects of visual cognitive tasks on landing stability and lower extremity injury risk in high-level soccer players

BackgroundVisual cognition plays a pivotal role in sports. It is widely recognized that there is an intriguing coupling that they could affect each other through interaction between visual cognition and motor control, but few studies linked the effects of visual cognitive tasks on landing stability to postural control and injury risk.Research questionWhether visual cognitive tasks affect the landing stability and lower limb injury risk of professional soccer players?MethodsThe current study used a three-dimensional Multiple Object Tracking (MOT) task to simulate visual cognitive difficulties experienced in soccer matches. Fifteen male high-level soccer athletes (height: 181.43 ± 7.36 cm, weight: 75.37 ± 10.67 kg, training years: 10.07 ± 2.98 yr) from our school team were recruited and completed a landing action from a high platform with and without MOT tasks. Vicon infrared high-speed motion capture system and three-dimensional force measuring platform were used to collect various outcomes simultaneously.ResultsThe Time to Stabilization (TTS) during landing was significantly prolonged, while the Medial-Lateral Stability Index (MLSI), Anterior-Posterior Stability (APSI), Dynamic Postural Index Stability Index (DPSI), the trajectory lengths, and envelope area of COP during landing were also increased during MOT dual-task.DiscussionThe decline of these indicators reflected the deterioration in postural stability and greater requirements for maintaining balance which could increase the risk of injury in soccer athletes. We advocate that adequate visual attention and visual information processing might play critical roles in maintaining dynamic balance through the supraspinal neural network.     

Injury prevention effects of stretching exercise intervention by physical therapists in male high school soccer players

We aimed to examine the prevalence of injury after physical therapy intervention for muscle tightness and injury prevention in male high school soccer players. A randomized controlled trial was conducted. Participants comprised 124 players from two high schools who competed in national tournament soccer games held from April 2018 to March 2019. Players were randomly divided into intervention (with a 12-week stretching intervention by physical therapists) and control groups (without the intervention). Players and coaches provided written information regarding injuries and daily training and match times; physical therapists visited each team weekly to collect data and review documentation. Muscle tightness and injury incidence, number, type, location, circumstances, situations, severity, and contents during the 12-week intervention period and a subsequent 40-week observation period were compared between groups. Injuries were significantly lower with intervention during the 40-week observation period (P < .01) but not during the 12-week intervention period (P = .44). Injury types mainly included disorder, non-contact, lower-limb/trunk, and muscle/tendon injuries. Significant interactions were observed for all tightness-test measurement items. The intervention group showed significant improvements in heel-buttock distance, and straight leg-raise and hip rotation angles (pre-intervention < 12 weeks < 52 weeks), as well as significant improvements in ankle dorsiflexion angles at 12 and 52 weeks (relative to pre-intervention values). Instructed stretching exercises, personally designed by physical therapists to address muscle tightness, improved the range of motion and trunk flexibility, with a positive effect on the injury rate in male high school soccer players, especially for non-contact disorder injuries during training.     

Instruction of jump-landing technique using videotape feedback: altering lower extremity motion patterns

BACKGROUND: Anterior cruciate ligament injury prevention programs have used videotapes of jump-landing technique as a key instructional component to improve landing performance. HYPOTHESIS: All videotape feedback model groups will increase knee flexion angles at initial contact and overall knee flexion motion and decrease peak vertical ground reaction forces and peak proximal anterior tibial shear forces to a greater extent than will a nonfeedback group. The secondary hypothesis is that the videotape feedback using the combination of the expert and self models will create the greatest change in each variable. STUDY DESIGN: Controlled laboratory study. METHODS: Knee kinematics and kinetics of college-aged recreational athletes randomly placed in 3 different videotape feedback model groups (expert only, self only, combination of expert and self) and a nonfeedback group were collected while participants performed a basketball jump-landing task on 3 testing occasions. RESULTS: All feedback groups significantly increased knee angular displacement flexion angles [F(6,70) = 8.03, P = .001] and decreased peak vertical ground reaction forces [F(6,78) = 2.68, P = .021] during performance and retention tests. The self and combination groups significantly increased knee angular displacement flexion angles more than the control group did; the expert model group did not change significantly more than the control group did. All feedback groups and the nonfeedback group significantly reduced peak vertical forces across performance and retention tests. There were no statistically significant changes in knee flexion angle at initial ground contact (P = .111) and peak proximal anterior tibial shear forces (P = .509) for both testing sessions for each group. CONCLUSION: The use of self or combination videotape feedback is most useful for increasing knee angular displacement flexion angles and reducing peak vertical forces during landing. CLINICAL RELEVANCE: The use of self or combination modeling is more effective than is expert-only modeling for the implementation of instructional programs aimed at reducing the risk of jump-landing anterior cruciate ligament injuries.     

The effect of a single treatment of the Protonics system on lower extremity kinematics during gait and the lateral step up exercise

INTRODUCTION: Patellofemoral pain (PFP) is often attributed to abnormal patellar tracking. The Protonics knee orthosis was developed to reduce femoral internal rotation by altering pelvic alignment via hamstring activation. The purpose of this research was to determine if a single treatment with the orthosis improved lower extremity alignment during gait and the lateral step up exercise. We hypothesized that anterior pelvic tilt, hip internal rotation and adduction, and external rotation of the tibia with respect to the femur would decrease after use of the brace. METHODS: Nineteen females (23.4+/-3.1 year, 1.66+/-0.05 m, 65.3+/-20.4 kg) with chronic PFP participated. Three-dimensional kinematic data were collected for each subject at 60 Hz during pre-treatment (PRE), after a placebo condition with the orthosis set at zero resistance (PLAC), and post-treatment (POST). Treatment consisted of having the subject perform the rehabilitation exercises recommended by the Protonics manufacturer. A repeated measures ANOVA was performed on each dependent variable (alpha=0.05). RESULTS: This investigation did not verify the changes in alignment proposed by the manufacturer as a result of acute application of the Protonics system. However, after the use of the brace, pelvic rotation and hip hike were decreased during the lateral step up exercise. CONCLUSION: Based on the results of this study, it was concluded that a single application of the Protonics system did not alter anterior pelvic tilt, hip internal rotation and adduction, or tibial external rotation during the lateral step up and gait.