Balance and muscle power of children with Charcot-Marie-Tooth

BACKGROUND:

In certain diseases, functional constraints establish a greater relationship with muscle power than muscle strength. However, in hereditary peripheral polyneuropathies, no such relationship was found in the literature.

OBJECTIVE:

In children with Charcot-Marie-Tooth (CMT), to identify the impact of muscle strength and range of movement on the static/dynamic balance and standing long jump based on quantitative and functional variables.

METHOD:

The study analyzed 19 participants aged between 6 and 16 years, of both genders and with clinical diagnoses of CMT of different subtypes. Anthropometric data, muscle strength of the lower limbs (hand-held dynamometer), ankle and knee range of movement, balance (Pediatric Balance Scale) and standing long jump distance were obtained by standardized procedures. For the statistical analysis, Pearson and Spearman correlation coefficients were used.

RESULTS:

There was a strong positive correlation between balance and the muscle strength of the right plantar flexors (r=0.61) and dorsiflexors (r=0.59) and a moderate correlation between balance and the muscle strength of inversion (r=0.41) and eversion of the right foot (r=0.44). For the long jump and range of movement, there was a weak positive correlation with right and left plantar flexion (r=0.20 and r=0.12, respectively) and left popliteal angle (r=0.25), and a poor negative correlation with left dorsiflexion (r=-0.15).

CONCLUSIONS:

The data on the patients analyzed suggests that the maintenance of distal muscle strength favors performance during balance tasks, while limitations in the range of movement of the legs seem not to be enough to influence the performance of the horizontal long jump.     

Analysis of postural control and muscular performance in young and elderly women in different age groups

BACKGROUND:

muscle strength and power are two factors affecting balance. The impact of muscle strength and power on postural control has not been fully explored among different age strata over sixty.

OBJECTIVES:

the aim of the present study was to assess the muscle strength and power of elderly women in different age groups and determine their correlation with postural control.

METHOD:

eighty women were divided into four groups: the young 18-30 age group (n=20); the 60-64 age group (n=20); the 65-69 age group (n=20); and the 70-74 age group (n=20). The participants underwent maximum strength (one repetition maximum or 1-RM) and muscle power tests to assess the knee extensor and flexor muscles at 40%, 70%, and 90% 1-RM intensity. The time required by participants to recover their balance after disturbing their base of support was also assessed.

RESULTS:

the elderly women in the 60-64, 65-69, and 70-74 age groups exhibited similar muscle strength, power, and postural control (p>0.05); however, these values were lower than those of the young group (p<0.05) as expected. There was a correlation between muscle strength and power and the postural control performance (p<0.05).

CONCLUSION:

despite the age difference, elderly women aged 60 to 74 years exhibited similar abilities to generate strength and power with their lower limbs, and this ability could be one factor that explains the similar postural control shown by these women.     

Shoulder isokinetic profile of male handball players of the Brazilian National Team

Background

Data obtained on an isokinetic dynamometer are useful to characterize muscle status and have been reported in muscle imbalance studies in different types of sport. However, few studies have assessed elite handball players to establish reference values.

Objective

The purpose of this study was to compare, for the dominant (D) and non-dominant (ND) side, the isokinetic profile of shoulder rotator muscle strength between male handball players (H) and asymptomatic non-athletes (NA).

Method

Isokinetic concentric and eccentric strength tests for D upper limbs were performed by the H group (n=20) and the NA group (n=12). Internal and external rotator muscle peak torque in concentric action was assessed at 60°/s and 300°/s and in eccentric action at 300°/s. We also calculated conventional balance (the ratio of external rotator peak torque to internal rotator peak torque in concentric action) and functional balance (the ratio of external rotator peak torque in eccentric action to internal rotator peak torque in concentric action).

Results

In the H group, dominant limbs were stronger in concentric action for external rotation at 60 and 300°/s. The conventional balance ratio for the D side was significantly lower at 60 and 300°/s for H compared to NA. The functional ratio for the D side was significantly lower at 300º/s for H compared to NA.

Conclusions

Compared to asymptomatic non-athletes, handball players presented significant muscular imbalance resulting from daily sports practice, a known risk factor for shoulder injuries.     

Influence of obstructive sleep apnea syndrome in the fluctuation of the submaximal isometric torque of knee extensors in patients with early-grade osteoarthritis

OBJECTIVE:

The aim of this study was to investigate whether obstructive sleep apnea (OSA) alters the fluctuation of submaximal isometric torque of the knee extensors in patients with early-grade osteoarthritis (OA).

METHOD:

The study included 60 male volunteers, aged 40 to 70 years, divided into four groups: Group 1 (G1) - Control (n=15): without OA and without OSA; Group 2 (G2) (n=15): with OA and without OSA; Group 3 (G3) (n=15): without OA and with OSA; and Group 4 (G4) (n=15) with OA and with OSA. Five patients underwent maximal isometric contractions of 10 seconds duration each, with the knee at 60° of flexion to determine peak torque at 60°. To evaluate the fluctuation of torque, 5 submaximal isometric contractions (50% of maximum peak torque) of 10 seconds each, which were calculated from the standard deviation of torque and coefficient of variation, were performed.

RESULTS:

Significant differences were observed between groups for maximum peak torque, while G4 showed a lower value compared with G1 (p=0.005). Additionally, for the average torque exerted, G4 showed a lower value compared to the G1 (p=0.036). However, no differences were found between the groups for the standard deviation (p=0.844) and the coefficient of variation (p=0.143).

CONCLUSION:

The authors concluded that OSA did not change the parameters of the fluctuation of isometric submaximal torque of knee extensors in patients with early-grade OA.     

Relationships among the Y balance test,Berg Balance Scale,and lower limb strength in middle-aged and older females

Background:

Older females have less dynamic postural control and muscle strength than do middle-aged females. Aging-related strength losses may limit balancing performance.

Objective:

The purpose of this study was to investigate the ability of the Y Balance Test (YBT) and lower limb strength to discriminate between females in 2 age groups, the relationship between YBT distance and the Berg Balance Scale (BBS), and the degree to which performance on YBT distance is related to lower limb strength in middle-aged and older females.

Method:

The 40 healthy, independently active females were divided into 2 groups: older and middle-aged. The participants underwent measurements of YBT distance using the YBT, maximal muscular strength of the lower limbs using a handheld dynamometer, and the BBS.

Results:

The YBT distance in 3 directions and lower limb muscle strength for both lower limbs were significantly lower in the older adults than in the middle-aged group. A moderate correlation but insignificant correlation was found between the YBT composite distance and the BBS score. In the older females, YBT distance was significantly positively correlated with strength of the knee flexor and hip abductor. In the middle-aged group, YBT distance was significantly positively correlated with strength of the knee flexor and hip extensor.

Conclusions:

Performance on the YBT was influenced by the strength of lower limb. We suggested that YBT can be used to alternative as a measurement of dynamic balance. Proper training programs for older people could include not only strengthening exercises but also YBT performance to improve balance.     

Determination of exacerbation predictors in patients with COPD in physical therapy - a longitudinal study

Background

Chronic obstructive pulmonary disease (COPD) typically presents the characteristic clinical condition of exacerbation, with more intense symptoms associated with greater functional loss and consequently lower chances of patient survival.

Objectives

This study sought to determine the predictors of exacerbation, alone or in combination, in patients with chronic obstructive pulmonary disease (COPD) who received physical therapeutic treatment over 6 months.

Method

This was an observational, longitudinal and prospective study in which 63 COPD patients residing within the municipality of São Carlos, SP, Brazil were evaluated. These patients had COPD stages II and III and were entered into a physical therapy program, consisting of 3 periods of assessment over 6 months. We evaluated the occurrence of acute exacerbation as well as the patients'' body mass index (BMI), fat-free mass (FFM), fat-free mass index, forced expiratory volume in 1 second (FEV₁), dyspnea, distance walked (DW) in the 6-minute walk test (6MWT) and handgrip strength.

Results

When applying Cox settings with each covariate separately, the results revealed 5% significance only for the DW in the 6MWT, which demonstrated an interaction between BMI and FFM. Comparison of the 3 periods of assessment across the covariates measured showed a significant difference only for the DW between evaluations in the 3^rd and 6^th months.

Conclusion

Upon analyzing the predictors of risk over 6 months of follow-up in patients with COPD, we found that the DW in the 6MWT was associated with the risk of exacerbation, although this risk also depended on the covariates BMI and FFM.     

Effect of upper extremity proprioceptive neuromuscular facilitation combined with elastic resistance bands on respiratory muscle strength: a randomized controlled trial

Background

Elastic resistance bands (ERB) combined with proprioceptive neuromuscular facilitation (PNF) are often used in resistance muscle training programs, which have potential effects on peripheral muscle strength. However, the effects of the combination of ERB and PNF on respiratory muscle strength warrant further investigation.

Objectives

The assessment of the effects of PNF combined with ERB on respiratory muscle strength.

Method

Twenty healthy, right-handed females were included. Subjects were randomized to either the resistance training program group (TG, n=10) or the control group (CG, n=10). Maximal expiratory pressure (MEP) and inspiratory pressure (MIP) were measured before and after four weeks of an upper extremity resistance training program. The training protocol consisted of upper extremity PNF combined with ERB, with resistance selected from 1 repetition maximum protocol.

Results

PNF combined with ERB showed significant increases in MIP and MEP (p<0.05). In addition, there were significant differences between the TG and CG regarding ∆MIP (p=0.01) and ∆MEP (p=0.04).

Conclusions

PNF combined with ERB can have a positive impact on respiratory muscle strength. These results may be useful with respect to cardiopulmonary chronic diseases that are associated with reduced respiratory muscle strength.     

Differences in muscle strength after ACL reconstruction do not influence cardiorespiratory responses to isometabolic exercise

Objectives

To investigate whether the muscle strength decrease that follows anterior cruciate ligament (ACL) reconstruction would lead to different cardiorespiratory adjustments during dynamic exercise.

Method

Eighteen active male subjects were submitted to isokinetic evaluation of knee flexor and extensor muscles four months after ACL surgery. Thigh circumference was also measured and an incremental unilateral cardiopulmonary exercise test was performed separately for both involved and uninvolved lower limbs in order to compare heart rate, oxygen consumption, minute ventilation, and ventilatory pattern (breath rate, tidal volume, inspiratory time, expiratory time, tidal volume/inspiratory time) at three different workloads (moderate, anaerobic threshold, and maximal).

Results

There was a significant difference between isokinetic extensor peak torque measured in the involved (116.5±29.1 Nm) and uninvolved (220.8±40.4 Nm) limbs, p=0.000. Isokinetic flexor peak torque was also lower in the involved limb than in the uninvolved limb (107.8±15.4 and 132.5±26.3 Nm, p=0.004, respectively). Lower values were also found in involved thigh circumference as compared with uninvolved limb (46.9±4.3 and 48.5±3.9 cm, p=0.005, respectively). No differences were found between the lower limbs in any of the variables of the incremental cardiopulmonary tests at all exercise intensities.

Conclusions

Our findings indicate that, four months after ACL surgery, there is a significant deficit in isokinetic strength in the involved limb, but these differences in muscle strength requirement do not produce differences in the cardiorespiratory adjustments to exercise. Based on the hypotheses from the literature which explain the differences in the physiological responses to exercise for different muscle masses, we can deduce that, after 4 months of a rehabilitation program after an ACL reconstruction, individuals probably do not present differences in muscle oxidative and peripheral perfusion capacities that could elicit higher levels of peripheral cardiorepiratory stimulus during exercise.     

Lower limb muscle strength is associated with functional performance and quality of life in patients with systemic sclerosis

Background:

Complaints of peripheral muscle weakness are quite common in patients with systemic sclerosis (SSc). It is likely that the muscle impairments may reduce the patients'' exercise performance, which in turn may decrease their functional capacity and exert a direct impact on their quality of life.

Objectives:

To assess the peripheral and respiratory muscle strength in individuals with SSc and to investigate their correlation with the 6-min walk distance (6MWD) and quality of life measurements. Moreover, we aimed to characterize their nutritional status, pulmonary function, functional capacity, and quality of life compared to the controls.

Method:

The present cross-sectional study included 20 patients with SSc and 20 control subjects. All of the participants were subjected to isometric dynamometry, surface electromyography, bioelectrical impedance analysis, pulmonary function testing, and the 6-min walk test. Patients with SSc also responded to the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the Health Assessment Questionnaire Disability Index (HAQ-DI).

Results:

The individuals with SSc exhibited a reduction in quadriceps strength (p=0.0001), increased quadriceps fatigability (p=0.034), impaired pulmonary function, and a reduced 6MWD (p=0.0001) compared to the controls. Quadriceps strength was significantly correlated with the 6MWD (Rho=0.719; p=0.0004) and the HAQ-DI (Rho=-0.622; p=0.003). We also found significant correlations between quadriceps fatigability and maximal inspiratory (Rho=0.684; p=0.0009) and maximal expiratory (Rho=0.472; p=0.035) pressure.

Conclusions:

Patients with SSc exhibited reduced respiratory muscle and quadriceps strength and an increase in its fatigability. In these individuals, there was a relationship between quadriceps strength, functional capacity, and quality of life.     

A COMPARISON OF CHANGE IN 3D SCAPULAR KINEMATICS WITH MAXIMAL CONTRACTIONS AND FORCE PRODUCTION WITH SCAPULAR MUSCLE TESTS BETWEEN ASYMPTOMATIC OVERHEAD ATHLETES WITH AND WITHOUT SCAPULAR DYSKINESIS

Background

The significance of scapular dyskinesis is being challenged due to a lack of the association with pain and ability to predict injury in athletic populations. However, it is unknown whether asymptomatic overhead athletes with dyskinesis cope by normalizing scapular position with higher demand activities.

Hypothesis/Purpose

The purpose of this study was to compare change in scapular kinematics from an active unweighted contraction to a maximal isometric contraction in asymptomatic overhead athletes with and without scapular dyskinesis. Secondarily, force generated with manual muscle tests were explored for differences and relationships with kinematics.

Study Design

Cross‐sectional laboratory study

Methods

Twenty‐five matched asymptomatic overhead athletes with (n=14) and without (n=11) scapular dyskinesis, defined with a reliable and validated clinical method, participated in this study. Three‐dimensional scapular kinematics were evaluated in an active unweighted condition, and during maximal isometric contractions at 90 ° of shoulder flexion. Isometric force produced with lower trapezius and serratus anterior manual muscle tests were assessed with a dynamometer. Changes in scapular kinematics were compared between groups. Differences in force generated with manual muscle tests between groups and relationships with kinematics were explored.

Results

Athletes with dyskinesis demonstrated greater deficits in scapular upward rotation with maximal contraction (p=<0.001), less external rotation (p=0.036) and weaker lower trapezius manual muscle test strength (p=0.031). Lower trapezius (p=0.003;r=0.57) and serratus anterior (p=0.042;r=0.41) manual muscle test strength deficits were fair to moderately associated with a lack of scapular upward rotation during maximal contraction.

Conclusion

Small to moderate changes in scapular kinematics are normal responses to a maximal contraction, but with scapular dyskinesis this response is accentuated. Athletes with dyskinesis generate less force with lower trapezius manual muscle testing compared to athletes without dyskinesis. Decreased strength with lower trapezius and serratus anterior manual muscle testing was also related to a lack of upward rotation in all athletes.

Level of Evidence

3     

Kinesio Taping effects on knee extension force among soccer players

Background:

Kinesio Taping (KT) is widely used, however the effects of KT on muscle activation and force are contradictory.

Objective:

To evaluate the effects of KT on knee extension force in soccer players.

Method:

This is a clinical trial study design. Thirty-four subjects performed two maximal isometric voluntary contractions of the lower limbs pre, immediately post, and 24 hours after tape application on the lower limbs. Both lower limbs were taped, using K-Tape and 3M Micropore tape randomly on the right and left thighs of the participants. Isometric knee extension force was measured for dominant side using a strain gauge. The following variables were assessed: peak force, time to peak force, rate of force development until peak force, time to peak rate of force development, and 200 ms pulse.

Results:

There were no statistically significant differences in the variables assessed between KT and Micropore conditions (F=0.645, p=0.666) or among testing sessions (pre, post, and 24h after) (F=0.528, p=0.868), and there was no statistical significance (F=0.271, p=0.986) for interaction between tape conditions and testing session.

Conclusion:

KT did not affect the force-related measures assessed immediately and 24 hours after the KT application compared with Micropore application, during maximal isometric voluntary knee extension.     

Balance,gait, functionality and strength: comparison between elderly fallers and non-fallers

BACKGROUND:

Accidental falls are a major health problem related to aging and affect one in every three elderly individuals over the age of sixty.

OBJECTIVE:

To evaluate and compare the muscle strength, gait kinematics parameters, and performance in functional tests between elderly subjects with and without a prior history of falls. In addition, the association between the history of falls and the variables that demonstrated differences between groups were tested.

METHOD:

62 elderly subjects participated in the study and were allocated to the group with falls history (FG; n=20; 68.0±6.9 years old) or the group without falls history (CG; n=42; 65.5±4.1 years old). Maximal strength, gait kinematics parameters, and functional tests were tested.

RESULTS:

The FG showed lower muscle strength in the knee flexors (51.45±8.6 vs. 62.09±19 Kg), lower average toe clearance during the swing phase (0.04±0.006 vs. 0.043 ± 0.005 m), and lower performance in the "8-foot up-and-go" test (5.3±0.7 vs. 5.8±0.7 s) (p<0.05). There were no associations between any variables and falls, but the increased time in the "8-foot up-and-go" test may double the likelihood of a fall occurring.

CONCLUSION:

Fallers have reduced lower limb strength, gait alterations, the worst performance in the dynamic balance test, and an increased risk of falls.     

Analysis of dimensions,activation and median frequency of cervical flexor muscles in young women with migraine or tension-type headache

Background:

Central and peripheral mechanisms may be involved in migraine and tension-type headache pathogenesis, however the role of muscle disorders in their pathophysiological mechanisms remains unclear.

Objectives:

To assess the association between the presence of migraine or tension-type headache and changes in longus colli muscle dimensions and sternocleidomastoid muscle activity.

Method:

An observational study with 48 women comparing the following groups: migraine (n=21), tension-type headache (n=16), and control (n=11). The cross-sectional area, lateral and anteroposterior dimensions, and shape ratio of the longus colli muscle were measured using ultrasound. The activation of the sternocleidomastoid muscle was assessed by signal amplitude and the decline in median frequency using surface electromyographic analysis.

Results:

The dimensions of the longus colli muscle did not differ between groups (p>0.05). Post-test analysis showed lower sternocleidomastoid muscle activation on both sides, at the onset of contraction, in the group with tension-type headache when compared to the control group {right sternocleidomastoid [tension-type headache: 0.39 (0.30-0.49); control: 0.58 (0.42-0.76); p=0.026] and left sternocleidomastoid [tension-type headache: 0.39 (0.31-0.48); control: 0.60 (0.42-0.79); p=0.039], Tukey''s post hoc test}. There was no difference between the three groups in sternocleidomastoid muscle activation, on both sides, at the end of contraction (p>0.05). Intergroup analysis showed no difference in the rate of decline in median frequency (p>0.05).

Conclusion:

The group with tension-type headache exhibited less activation at the onset of sternocleidomastoid muscle contraction. No association was observed between the presence of headache and alterations in longus colli muscle dimensions, median frequency, and sternocleidomastoid muscle activation at the end of contraction.     

Influence of dual task and frailty on gait parameters of older community-dwelling individuals

Background:

Gait parameters such as gait speed (GS) are important indicators of functional capacity. Frailty Syndrome is closely related to GS and is also capable of predicting adverse outcomes. The cognitive demand of gait control is usually explored with dual-task (DT) methodology.

Objective:

To investigate the effect of DT and frailty on the spatio-temporal parameters of gait in older people and identify which variables relate to GS.

Method:

The presence of frailty was verified by Fried''s Frailty Criteria. Cognitive function was evaluated with the Mini-Mental State Exam (MMSE) and gait parameters were analyzed through the GAITRite^(r) system in the single-task and DT conditions. The Kolmogorov-Smirnov, ANOVA, and Pearson''s Correlation tests were administered.

Results:

The participants were assigned to the groups frail (FG), pre-frail (PFG), and non-frail (NFG). During the DT, the three groups showed a decrease in GS, cadence, and stride length and an increase in stride time (p<0.001). The reduction in the GS of the FG during the DT showed a positive correlation with the MMSE scores (r=730; p=0.001) and with grip strength (r=681; p=0.001).

Conclusions:

Gait parameters are more affected by the DT, especially in the frail older subjects. The reduction in GS in the FG is associated with lower grip strength and lower scores in the MMSE. The GS was able to discriminate the older adults in the three levels of frailty, being an important measure of the functional capacity in this population.     

Respiratory muscle endurance is limited by lower ventilatory efficiency in post-myocardial infarction patients

Background

Reduced respiratory muscle endurance (RME) contributes to increased dyspnea upon exertion in patients with cardiovascular disease.

Objective

The objective was to characterize ventilatory and metabolic responses during RME tests in post-myocardial infarction patients without respiratory muscle weakness.

Method

Twenty-nine subjects were allocated into three groups: recent myocardial infarction group (RG, n=9), less-recent myocardial infarction group (LRG, n=10), and control group (CG, n=10). They underwent two RME tests (incremental and constant pressure) with ventilatory and metabolic analyses. One-way ANOVA and repeated measures one-way ANOVA, both with Tukey post-hoc, were used between groups and within subjects, respectively.

Results

Patients from the RG and LRG presented lower metabolic equivalent and ventilatory efficiency than the CG on the second (50± 06, 50± 5 vs. 42± 4) and third part (50± 11, 51± 10 vs. 43± 3) of the constant pressure RME test and lower metabolic equivalent during the incremental pressure RME test. Additionally, at the peak of the incremental RME test, RG patients had lower oxygen uptake than the CG.

Conclusions

Post-myocardial infarction patients present lower ventilatory efficiency during respiratory muscle endurance tests, which appears to explain their inferior performance in these tests even in the presence of lower pressure overload and lower metabolic equivalent.     

AN ANALYSIS OF PEAK PELVIS ROTATION SPEED,GLUTEUS MAXIMUS AND MEDIUS STRENGTH IN HIGH VERSUS LOW HANDICAP GOLFERS DURING THE GOLF SWING

Purpose/Hypothesis:

The kinematic sequence of the golf swing is an established principle that occurs in a proximal-to-distal pattern with power generation beginning with rotation of the pelvis. Few studies have correlated the influence of peak pelvis rotation to the skill level of the golfer. Furthermore, minimal research exists on the strength of the gluteal musculature and their ability to generate power during the swing. The purpose of this study was to explore the relationship between peak pelvis rotation, gluteus medius and gluteus maximus strength, and a golfer''s handicap.

Subjects:

56 healthy subjects.

Material/Methods:

Each subject was assessed using a hand-held dynamometry device per standardized protocol to determine gluteus maximus and medius strength. The K-vest was placed on the subject with electromagnetic sensors at the pelvis, upper torso, and gloved lead hand to measure the rotational speed at each segment in degrees/second. After K-vest calibration and 5 practice swings, each subject hit 5 golf balls during which time, the sensors measured pelvic rotation speed.

Results:

A one-way ANOVA was performed to determine the relationships between peak pelvis rotation, gluteus medius and gluteus maximus strength, and golf handicap. A significant difference was found between the following dependent variables and golf handicap: peak pelvis rotation (p=0.000), gluteus medius strength (p=0.000), and gluteus maximus strength (p=0.000).

Conclusion:

Golfers with a low handicap are more likely to have increased pelvis rotation speed as well as increased gluteus maximus and medius strength when compared to high handicap golfers.

Clinical Relevance:

The relationships between increased peak pelvis rotation and gluteus maximus and medius strength in low handicap golfers may have implications in designing golf training programs. Further research needs to be conducted in order to further explore these relationships.     

ASSOCIATION OF ISOMETRIC STRENGTH OF HIP AND KNEE MUSCLES WITH INJURY RISK IN HIGH SCHOOL CROSS COUNTRY RUNNERS

Background

High school cross country runners have a high incidence of overuse injuries, particularly to the knee and shin. As lower extremity strength is modifiable, identification of strength attributes that contribute to anterior knee pain (AKP) and shin injuries may influence prevention and management of these injuries.

Purpose

To determine if a relationship existed between isometric hip abductor, knee extensor and flexor strength and the incidence of AKP and shin injury in high school cross country runners.

Materials/Methods

Sixty‐eight high school cross country runners (47 girls, 21 boys) participated in the study. Isometric strength tests of hip abductors, knee extensors and flexors were performed with a handheld dynamometer. Runners were prospectively followed during the 2014 interscholastic cross country season for occurrences of AKP and shin injury. Bivariate logistic regression was used to examine risk relationships between strength values and occurrence of AKP and shin injury.

Results

During the season, three (4.4%) runners experienced AKP and 13 (19.1%) runners incurred a shin injury. Runners in the tertiles indicating weakest hip abductor (chi‐square = 6.140; p=0.046), knee extensor (chi‐square = 6.562; p=0.038), and knee flexor (chi‐square = 6.140; p=0.046) muscle strength had a significantly higher incidence of AKP. Hip and knee muscle strength was not significantly associated with shin injury.

Conclusions

High school cross country runners with weaker hip abductor, knee extensor and flexor muscle strength had a higher incidence of AKP. Increasing hip and knee muscle strength may reduce the likelihood of AKP in high school cross country runners.

Level of Evidence

2b     

Effectiveness of muscle strengthening and description of protocols for preventing falls in the elderly: a systematic review

Background

Falls are a geriatric syndrome that is considered a significant public health problem in terms of morbidity and mortality because they lead to a decline in functional capacity and an impaired quality of life in the elderly. Lower limb muscle strengthening seems to be an effective intervention for preventing falls; however, there is no consensus regarding the best method for increasing lower limb muscle strength.

Objectives

To analyze the effectiveness of lower limb muscle strengthening and to investigate and describe the protocols used for preventing falls in elderly subjects.

Method

We performed a systematic review of randomized and controlled clinical trials published between 2002 and 2012 in the databases PubMed, EMBASE, Scopus, Web of Science, and PEDro that cited some type of lower limb muscle strengthening protocol and that evaluated the incidence of falls as the primary outcome exclusively in elderly subjects. Twelve studies met the inclusion criteria. Qualitative analysis was performed by independent reviewers applying the PEDro scale.

Results

The data obtained from the selected studies showed lower fall rates in the intervention groups compared to controls. Six studies described the lower limb muscle strengthening protocol in detail. High methodological quality was found in 6 studies (PEDro score ≥7/10 points).

Conclusions

The methodological quality of the studies in this area appears to leave little doubt regarding the effectiveness of lower limb strengthening exercises for preventing falls in elderly subjects, however the interventions in these studies were poorly reported.     

Lung function and six-minute walk test performance in individuals with sickle cell disease

Background

Sickle Cell Disease (SCD), which is characterized by a mutation in the gene encoding beta hemoglobin, causes bodily dysfunctions such as impaired pulmonary function and reduced functional capacity.

Objective

To assess changes in pulmonary function and functional capacity in patients with SCD and to identify the relationships between these variables.

Method

We evaluated sociodemographic, anthropometric, lung function (spirometry), respiratory (manovacuometer), peripheral muscle strength (Handgrip strength - HS) and functional capacity (i.e., the six-minute walk test) parameters in 21 individuals with SCD (average age of 29±6 years). Shapiro-Wilk, paired Student''s, Wilcoxon, Pearson and Spearman correlation tests were used for statistical analyses, and the significance threshold was set at p<0.05.

Results

A total of 47.6% of the study subjects exhibited an altered ventilation pattern, 42.8% had a restrictive ventilatory pattern (RVP) and 4.8% exhibited a mixed ventilatory pattern (MVP). The observed maximal inspiratory pressure (MIP) values were below the predicted values for women (64 cmH₂O), and the maximum expiratory pressure (MEP) values, HS values and distance walked during the 6MWT were below the predicted values for both men (103 cmH₂O, 39 Kgf and 447 m, respectively) and women (64 cmH₂O; 27 Kgf; 405 m, respectively). Positive correlations were observed between maximum voluntary ventilation (MVV) and MEP (r=0.4; p=0.046); MVV and BMI (r=0.6; p=0.003); and between HS and MIP (r=0.7; p=0.001), MEP (r=0.6; p=0.002), MVV (r=0.5; p=0.015), distance walked in the 6MWT (r=0.4; p=0.038) and BMI (r=0.6; p=0.004).

Conclusions

SCD promoted changes in lung function and functional capacity, including RVPs and a reduction in the distance walked in the 6MWT when compared to the predictions. In addition, significant correlations between the variables were observed.     

Effectiveness of hip muscle strengthening in patellofemoral pain syndrome patients: a systematic review

Introduction:

Patellofemoral pain syndrome (PFPS) is characterized by anterior knee pain, which may limit the performance of functional activities. The influence of hip joint motion on the development of this syndrome has already been documented in the literature. In this regard, studies have investigated the effectiveness of hip muscle strengthening in patients with PFPS.

Objectives:

The aims of this systematic review were (1) to summarize the literature related to the effects of hip muscle strengthening on pain intensity, muscle strength, and function in individuals with PFPS and (2) to evaluate the methodological quality of the selected studies.

Method:

A search for randomized controlled clinical trials was conducted using the following databases: Google Scholar, MEDLINE, PEDro, LILACS, and SciELO. The selected studies had to distinguish the effects of hip muscle strengthening in a group of patients with PFPS, as compared to non-intervention or other kinds of intervention, and had to investigate the following outcomes: pain, muscle strength, and function. The methodological quality of the selected studies was analyzed by means of the PEDro scale.

Results:

Seven studies were selected. These studies demonstrated that hip muscle strengthening was effective in reducing pain. However, the studies disagreed regarding the treatments'' ability to improve muscle strength. Improvement in functional capabilities after hip muscle strengthening was found in five studies.

Conclusion:

Hip muscle strengthening is effective in reducing the intensity of pain and improving functional capabilities in patients with PFPS, despite the lack of evidence for its ability to increase muscle strength.