Exploring overweight and obesity beyond body mass index: A body composition analysis in people with and without patellofemoral pain.

BACKGROUND: We compared body mass index (BMI), body fat, and skeletal muscle mass between (1) a mixed-sex nonathletic cohort of people with patellofemoral pain (PFP) and pain-free people, and (2) a nonathletic cohort of people with PFP and pain-free people subgrouped by sex (i.e., men and women with PFP vs. pain-free men and women). METHODS: This cross-sectional study included 114 people with PFP (71 women, 43 men) and 54 pain-free controls (32 women, 22 men). All participants attended a single testing session to assess body composition measures, which included BMI, percentage of body fat (%BFBioimpedance), and skeletal muscle mass (both assessed by bioelectrical impedance analysis), and percentage of body fat (%BFSkinfold) (assessed by skinfold caliper analysis). A one-way univariate analysis of covariance (age and physical activity levels as covariates) was used to compare body composition measures between groups (i.e., PFP vs. pain-free group; women with PFP vs. pain-free women; men with PFP vs. pain-free men). RESULTS: Women with PFP presented significantly higher BMI, %BFBioimpedance, and %BFSkinfold, and lower skeletal muscle mass compared to pain-free women (p ≤ 0.04; effect size : ‒0.47 to 0.85). Men with PFP and men and women combined had no differences in BMI, %BFBioimpedance, %BFSkinfold, and skeletal muscle mass compared to their respective pain-free groups (p > 0.05). CONCLUSION: Our findings indicate that BMI and body composition measures should be considered as part of the evaluation and management of people with PFP, especially in women, who have demonstrated higher BMI and body fat and lower skeletal muscle mass compared to pain-free controls. Future studies should not assess body composition measures in a mixed-sex population without distinguishing men participants from women participants.

Overweight and obesity in young adults with patellofemoral pain: Impact on functional capacity and strength.

PURPOSE: This study aimed to (a) investigate the proportion of overweight/obesity in a cohort of young adults with patellofemoral pain (PFP) and (b) explore the association of body mass index (BMI), body fat, and lean mass with functional capacity and hip and knee strength in people with PFP. METHODS: We included a mixed-sex sample of young adults (18-35 years old) with PFP (n = 100). Measurements for BMI, percentage of body fat, and lean mass (assessed by bioelectrical impedance) were obtained. Functional capacity was assessed by the Anterior Knee Pain Scale, plank test, and single-leg hop test. Strength of the knee extensors, knee flexors, and hip abductors was evaluated isometrically using an isokinetic dynamometer. The proportion of overweight/obesity was calculated based on BMI. The association between BMI, body fat, and lean mass and functional capacity and strength was investigated using partial correlations, followed by hierarchical regression analysis, adjusted for covariates (sex, bilateral pain, and current pain level). RESULTS: A total of 38% of our cohort had their BMI categorized as overweight/obese. Higher BMI was associated with poor functional capacity (ΔR2 = 0.06-0.12, p ≤ 0.001) and with knee flexion strength only (ΔR2 = 0.04, p = 0.030). Higher body fat was associated with poor functional capacity (ΔR2 = 0.05-0.15, p ≤ 0.015) and reduced strength (ΔR2 = 0.15-0.23, p < 0.001). Lower lean mass was associated with poor functional capacity (ΔR2 = 0.04-0.13, p ≤ 0.032) and reduced strength (ΔR2 = 0.29- 0.31, p < 0.001). CONCLUSION: BMI, body fat, and lean mass should be considered in the assessment and management of young people with PFP because it may be detrimental to function and strength.

Body fat and skeletal muscle mass, but not body mass index, are associated with pressure hyperalgesia in young adults with patellofemoral pain.

BACKGROUND: Young adults with patellofemoral pain (PFP) have a high prevalence of being overweight or obese, which is associated with impaired lower limb function and muscle weakness. However, the impact of being overweight or obese on pain sensitivity has not been explored. OBJECTIVES: We investigated the association between body fat, skeletal muscle mass, and body mass index (BMI) with pressure hyperalgesia and self-reported pain in young adults with PFP. METHODS: 114 adults with PFP (24 ± 5 years old, 62% women) were recruited. Demographics and self-reported pain (current and worst knee pain intensity in the previous month - 0-100 mm visual analog scale) were recorded. Body fat and skeletal muscle mass were measured using bioelectrical impedance. Pressure hyperalgesia was measured using a handheld algometer (pressure pain threshold) at three sites: center of patella of the painful knee, ipsilateral tibialis anterior, and contralateral upper limb. The association between body fat, skeletal muscle mass, and BMI with pressure hyperalgesia and self-reported pain were investigated using partial correlations and hierarchical regression models (adjusted for sex, bilateral pain, and symptoms duration). RESULTS: Higher body fat and lower skeletal muscle mass were associated with local, spread, and widespread pressure hyperalgesia (ΔR2=0.09 to 0.17, p ≤ 0.001; ΔR2=0.14 to 0.26, p<0.001, respectively), and higher current self-reported pain (ΔR2=0.10, p<0.001; ΔR2=0.06, p = 0.007, respectively). Higher BMI was associated with higher current self-reported pain (ΔR2=0.10, p = 0.001), but not with any measures of pressure hyperalgesia (p>0.05). CONCLUSION: Higher body fat and lower skeletal muscle mass help to explain local, spread, and widespread pressure hyperalgesia, and self-reported pain in people with PFP. BMI only helps to explain self-reported pain. These factors should be considered when assessing people with PFP and developing their management plan, but caution should be taken as the strength of association was generally low.

Kinesiophobia, but not strength is associated with altered movement in women with patellofemoral pain.

BACKGROUND: Evidence indicates the presence of both kinesiophobia and knee extension strength deficits in women with patellofemoral pain (PFP). Both impairments may contribute to apparent compensatory gait patterns including reduced cadence and peak knee flexion during stair negotiation. RESEARCH QUESTION: Is kinesiophobia or knee extension strength associated with movement pattern in women with patellofemoral pain? METHODS: Forty women with PFP were assessed with three-dimensional kinematic analyses during stair descent; isokinetic dynamometry of the knee extensors (isometric, concentric and eccentric); and the Tampa scale for kinesiophobia. Pearson coefficients were calculated to determine relationship among variables. RESULTS: Kinesiophobia correlated significantly with cadence (r = -0.62, p < 0.001), and peak knee flexion (r = -0.76, p < 0.001). No significant correlations were found between any knee extensor strength variables and kinematics (cadence or peak knee flexion); or kinesiophobia (p > 0.05). SIGNIFICANCE: Findings of this study could suggest addressing strength impairments alone may not adequately address kinesiophobia and movement pattern impairments in women with PFP. However, high-quality randomised controlled trials are needed to test this assumption. Further value may be added if currently evidence-based knee strengthening exercise is combined with education and/or graded exposure to address kinesiophobia, and consideration to gait retraining to address altered movement patterns at the knee.

Patellar Tendon Reflex and Vastus Medialis Hoffmann Reflex Are Down Regulated and Correlated in Women With Patellofemoral Pain.

OBJECTIVES: The aims of this study were threefold: (1) to compare the amplitude of patellar tendon reflex (T-reflex) between women with patellofemoral pain (PFP) and pain-free controls; (2) to compare the amplitude of vastus medialis Hoffmann reflex (VM H-reflex) between women with PFP and pain-free controls; (3) to investigate the association between the amplitude of patellar T-reflex and VM H-reflex in women with PFP and pain-free controls. DESIGN: Cross-sectional observational study. SETTING: Laboratory of biomechanics and motor control. PARTICIPANTS: Thirty women with PFP and 30 pain-free women aged 18 to 35 years (N=60). MAIN OUTCOME MEASURES: Peak-to-peak amplitudes of maximal VM H-reflex (elicited via electrical stimulation on the femoral nerve) and patellar T-reflex (elicited via mechanical percussion on the patellar tendon) were estimated. RESULTS: Women with PFP had significant lower amplitude of patellar T-reflex (mean difference=0.086; 95% confidence interval=0.020 to 0.151; P=.010; moderate effect) and VM H-reflex (mean difference=0.150; 95% confidence interval =0.073 to 0.227; P<.001; large effect) compared to pain-free controls. The VM H-reflex was strongly correlated with patellar T-reflex in both PFP group (r=0.66; P<.001) and control group (r=0.72; P<.001). CONCLUSIONS: As the T-reflex is easier to perform than H-reflex assessments in a clinical setting, it represents a feasible option to assess the impaired excitability of the stretch reflex pathway associated with PFP.

Relationship between knee abduction moment with patellofemoral joint reaction force, stress and self-reported pain during stair descent in women with patellofemoral pain.

BACKGROUND: Increased external knee abduction moment has been proposed as a risk factor for patellofemoral pain. This alteration is thought to be associated with elevated patellofemoral joint reaction force and stress, however these relationships remain poorly explored. Therefore, this study aimed at comparing knee abduction moment parameters (peak, rate of moment development and impulse), patellofemoral joint reaction force and stress of women with patellofemoral pain and pain-free controls during stair descent; and investigating the relationship among these variables with self-reported pain. METHODS: Kinetic data was obtained by inverse-dynamics equations and a previously reported algorithmic model was used to determine patellofemoral joint reaction force and stress. Participants' worst pain in the last month and pain level during stair descent were evaluated using a visual analogue scale. FINDINGS: Women with patellofemoral pain presented higher peak, rate of moment development and impulse of the external knee abduction moment, patellofemoral joint reaction force and stress (p = 0.005 to 0.04, effect size = 0.52 to 0.96) during stair descent than pain-free controls. Only knee abduction moment impulse presented positive moderate correlations with worst pain level in the last month (r = 0.53, p < 000.1), pain level during stair descent (r = 0.33, p = 0.042), patellofemoral joint reaction force (r = 0.65, p < 000.1) and stress (r = 0.58, p < 000.1). INTERPRETATION: These findings indicate that strategies aimed at decreasing external knee abduction moment impulse could reduce the load over the patellofemoral joint and improve pain of women with patellofemoral pain.

Implications of knee crepitus to the overall clinical presentation of women with and without patellofemoral pain.

OBJECTIVES: Compare anthropometric characteristics, function, kinesiophobia, catastrophism and knee extensor strength between women (i) with PFP and crepitus (PFPcrepitus); (ii) with PFP and no crepitus (PFPNOcrepitus); (iii) without PFP and crepitus (Pain-freecrepitus); and (iv) without PFP and no crepitus (Pain-freeNOcrepitus). DESIGN: Cross-sectional. SETTING: Laboratory study. PARTICIPANTS: 65 women with PFP and 51 pain-free women. MAIN OUTCOME MEASURES: Objective assessment of knee crepitus, forward step-down and single leg hop tests; knee extensor strength tests; and subjective ratings of function, kinesiophobia, pain catastrophising and knee stiffness. RESULTS: Crepitus was more common in women with PFP (50.7%) compared to those without (33.3%) (χ(1)2=4.17;p=0.031). PFPcrepitus and PFPNOcrepitus groups had lower self-reported function; and higher kinesiophobia, catastrophism and knee stiffness compared to Pain-freecrepitus and Pain-freeNOcrepitus groups (p < 0.001). PFPcrepitus, PFPNOcrepitus and Pain-freecrepitus groups had lower functional performance compared to the Pain-freeNOcrepitus group (p < 0.040). PFPcrepitus and PFPNOcrepitus groups had lower isometric, concentric and eccentric knee extensor strength compared to the Pain-freeNOcrepitus group (p < 0.041), but not the pain-freecrepitus group. PFPcrepitus presented higher BMI than other groups (p = 0.001). CONCLUSION: Kinesiophobia, catastrophism, knee stiffness, strength and physical function are all impaired in women with PFP, regardless of crepitus. In pain-free women, crepitus was associated with poorer objective function.

Differences in pain and function between adolescent athletes and physically active non-athletes with patellofemoral pain.

OBJECTIVES: To investigate pain level and function limitation in adolescent athletes and physically active non-athletes with PFP. DESIGN: Cross-sectional study. SETTING: Adolescent athletes were recruited at a sport center complex. Adolescent non-athletes were recruited from upper secondary schools. PARTICIPANTS: 108 adolescents diagnosed with PFP: 42 adolescent athletes and 66 adolescent non-athletes. MAIN OUTCOME MEASURES: To evaluate the level of pain, a visual analog scale (VAS) was used and to evaluate the overall function, the Knee Outcome in Osteoarthritis Survey (KOOS) was used. RESULTS: The adolescent athletes scored significantly higher in the VAS (Mean difference = 0.97 (95% CI = 0.35; 1.60) p = 0.003) compared to adolescent non-athletes. Adolescent athletes scored lower in the KOOS - Symptoms, Pain, Knee-related quality of life and Sport and recreation dimensions - than the non-athletes, however, the minimally clinically important difference was not achieved in Pain dimension. There was no significant difference in the Activities of daily living dimension of the KOOS. CONCLUSIONS: Adolescent athletes presented higher levels of pain and lower physical function status compared with physically active non-athletes. This provides an important insight to the management of PFP in adolescent athletes as worst functional status is linked with poor prognosis in patients with PFP.

Knee crepitus is prevalent in women with patellofemoral pain, but is not related with function, physical activity and pain.

OBJECTIVES: (i) To assess the reliability of knee crepitus measures, (ii) to investigate the association between knee crepitus and PFP; (iii) to investigate the relationship between knee crepitus with self-reported function, physical activity and pain. DESIGN: Cross-sectional. SETTING: Laboratory-based study. PARTICIPANTS: 165 women with PFP and 158 pain-free women. MAIN OUTCOME MEASURES: Knee crepitus test, anterior knee pain scale (AKPS) and self-reported worst knee pain in the last month, knee pain after 10 squats and knee pain after 10 stairs climbing. RESULTS: Knee crepitus clinical test presented high reliability Kappa value for PFP group was 0.860 and for pain-free group was 0.906. There is a significantly greater proportion of those with crepitus in the PFP group than in the pain-free group (OR = 4.19). Knee crepitus had no relationship with function (rpb = 0.03; p = 0.727), physical activity level (rpb = 0.010; p = 0.193), worst pain (rpb = 0.11; p = 0.141), pain climbing stairs (rpb = 0.10; p = 0.194) and pain squatting (rpb = 0.02; p = 0.802). CONCLUSION: Women who presents knee crepitus have 4 times greater odds to be in a group with PFP compared to those who do not. However, knee crepitus has no relationship with self-reported clinical outcomes of women with PFP.

Which is the best predictor of excessive hip internal rotation in women with patellofemoral pain: Rearfoot eversion or hip muscle strength? Exploring subgroups.

BACKGROUND: Patellofemoral pain (PFP) has been linked to increased patellofemoral joint stress as a result of excessive hip internal rotation. Lower hip strength and/or excessive rearfoot eversion have been used to explain such altered movement pattern; however, it is unknown which one is the best predictor of excessive hip internal rotation. RESEARCH QUESTION: To investigate if peak rearfoot eversion and/or peak concentric hip abductor strength can predict peak hip internal rotation during stair ascent in women with PFP. METHODS: This cross-sectional study included thirty-seven women with PFP which underwent three-dimensional kinematic analysis during stair ascent and hip abductor strength analysis in an isokinetic dynamometer. A forced entry linear regression model analysis was carried out to determine which independent variables present the best capability to predict the hip internal rotation. RESULTS: Peak concentric hip abductor strength significantly predicted peak hip internal rotation during stair ascent (R2 = 0.27, p = 0.001). Peak rearfoot eversion did not predict peak hip internal rotation during stair ascent (R2 < 0.01, p = 0.62). A Post-hoc analysis was conducted to explore if a subgroup with excessive rearfoot eversion would predict hip internal rotation. Based on a previous reported cut-off point, 48.6% of the participants were classified as excessive rearfoot eversion. For the subgroup with excessive rearfoot eversion, peak concentric hip abductor strength and peak rearfoot eversion significantly predicted peak hip internal rotation during stair ascent (R2 = 0.26, p = 0.02; R2 = 0.42, p = 0.003, respectively). For non-excessive rearfoot eversion subgroup, peak concentric hip abductor strength significantly predicted peak hip internal rotation during stair ascent (R2 = 0.53; p < 0.001); and peak rearfoot eversion did not (R2 = 0.01; p = 0.65). SIGNIFICANCE: Findings indicate that hip muscle strength seems to be related with hip internal rotation in all women with PFP. Rearfoot eversion seems to be related with hip internal rotation only in a subgroup with excessive rearfoot eversion.

What interventions can improve quality of life or psychosocial factors of individuals with knee osteoarthritis? A systematic review with meta-analysis of primary outcomes from randomised controlled trials.

OBJECTIVE: To systematically review evidence of primary outcomes from randomised controlled trials (RCTs) examining the effect of treatment strategies on quality of life (QoL) or psychosocial factors in individuals with knee osteoarthritis (OA). DESIGN: Systematic review with meta-analysis. DATA SOURCES: Medline, Embase, SPORTDiscus, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Web of Science were searched from inception to November 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included RCTs investigating the effect of conservative interventions on QoL or psychosocial factors in individuals with knee OA. Only RCTs considering these outcomes as primary were included. RESULTS: Pooled data supported the use of exercise therapy compared with controls for improving health-related and knee-related QoL. There was limited evidence that a combined treatment of yoga, transcutaneous electrical stimulation and ultrasound may be effective in improving QoL. Limited evidence supported the use of cognitive behavioural therapies (with or without being combined with exercise therapy) for improving psychosocial factors such as self-efficacy, depression and psychological distress. SUMMARY/CONCLUSION: Exercise therapy (with or without being combined with other interventions) seems to be effective in improving health-related and knee-related QoL or psychosocial factors of individuals with knee OA. In addition, evidence supports the use of cognitive behavioural therapies (with or without exercise therapy) for improving psychosocial factors such as self-efficacy, depression and psychological distress in individuals with knee OA. PROSPERO REGISTRATION NUMBER: CRD42016047602.

Higher pain level and lower functional capacity are associated with the number of altered kinematics in women with patellofemoral pain.

This study investigated whether women with patellofemoral pain (PFP) present kinematic alterations in proximal, local, and distal factors simultaneously, and determined the association between the number of kinematic alterations, pain level, and functional status. A three-dimensional motion analysis system was used to analyze the peak hip adduction, peak knee flexion, and peak rearfoot eversion, addressing the proximal, local, and distal factors, respectively, in fifty women. Functional status and pain level were assessed using the anterior knee pain scale (AKPS) and a visual analogic scale. Receiver operating characteristic curves were calculated to identify participants with and without kinematic alterations and the number of them was obtained for each participant. Associations between the number of kinematic alterations, pain level, and AKPS score were determined by the Pearson correlation. Results showed that 52% of women with PFP presented at least two kinematic alterations of which 24% were local/proximal, 16% local/distal, and 12% proximal/distal. Three kinematic alterations were found in 48% of the women with PFP. A strong positive correlation was found between the number of kinematic alterations and pain (r=0.78; p<0.001). A strong negative correlation was found between the number of altered kinematics and functional status (r=-0.79; p<0.001). Findings revealed that women with PFP presented at least two kinematic alterations and a higher number of kinematic alterations was associated with higher pain levels and lower functional status. Clinicians should carefully assess movement pattern of women with PFP as it could indicate a more severe condition, which is associated with a poor prognosis.

Efeito da Realidade Virtual no deslocamento do COP de indivíduos com hemiplegia / Effect of Virtual Reality on the COP displacement of individuals with hemiplegia

Introdução: O Traumatismo Cranioencefálico (TCE) é uma das principais causas de incapacidade funcional e alteração motora na população adulta. Objetivo: Avaliar o efeito da terapia com Wii no deslocamento do COP de hemiplégicos devido à sequela TCE. Métodos: Foram realizadas 10 sessões de treinamento com o Nintendo Wii Fit® em 10 indivíduos hemiplégicos pós TCE, do sexo masculino, com média de 31,3 ± 2,9 anos de idade. Os participantes foram avaliados antes, após e 3 meses após o protocolo de treinamento, nas quais mediu-se os dados cinéticos. Resultados: Não foram encontradas diferenças na RMS e velocidade do deslocamento do COP nos sentidos ântero-posterior e médio-lateral dos sujeitos hemiplégicos após as 10 sessões de treinamento com o console Wii. Esses valores se mantiveram após 3 meses. Conclusão: A terapia com o console Wii não alterou o deslocamento do COP nos sentidos ântero-posterior e médio-lateral de indiví-duos com hemiplegia.

Introducion: The Traumatic brain injury (TBI) is a major cause of disability and motor disorders in adults. Objective: To evaluate the effects of Wii rehabilitation therapy on COP displacement of hemiplegic individuals due to traumatic brain injury. Methods: 10 hemiplegic individuals after TBI were recruited for this study. Mean age, height and weight were 31.3 ± 2.9 years, 1.72 ± 0.03 m and 74.5 ± 5.1 kg, respectively. The individuals were evaluated before and after the training protocol and after 3 months again, in which kinetic data of the ground reaction force were measured. Results: There were no significant differences in the anterior-posterior and medio-lateral displacement of hemiplegic subjects after the 10 training sessions with the Wii console and these values remained the same after 3 months. Conclusion: The therapy with the Wii console was unable to alter the COP displacement of individuals with hemiplegia.

Contribution of altered hip, knee and foot kinematics to dynamic postural impairments in females with patellofemoral pain during stair ascent.

BACKGROUND: Altered hip, knee and foot kinematics have been systematically observed in individuals with patellofemoral pain (PFP). However, less attention has been given to the altered dynamic postural control associated with PFP. Additionally, the relative contribution of kinematic impairments to the postural behavior of subjects with PFP remains an open question that warrants investigation. The aims of this study were: i) to investigate possible differences in hip adduction, rearfoot eversion, knee flexion and displacement area of the center of pressure (COP) in individuals with PFP in comparison to controls during stair ascent; and (ii) to determine which kinematic parameter is the best predictor of the displacement area of the COP measured during the stance phase of the stair ascent. METHODS: Twenty-nine females with PFP and 25 asymptomatic pain-free females underwent three-dimensional kinematic and COP analyses during stair ascent. Between-group comparisons were made using independent t-tests. Regression models were performed to identify the capability of each kinematic factor in predicting the displacement area of the COP. RESULTS: Reduced knee flexion and displacement area of the COP as well as increased peak hip adduction and peak rearfoot eversion were observed in individuals with PFP as compared to controls. Peak hip adduction was the best predictor of the displacement area of the COP (r(2)=23.4%). CONCLUSIONS: The excessive hip adduction was the biggest predictor of the displacement area of the COP. CLINICAL RELEVANCE: Based on our findings, proximally targeted interventions may be of major importance for the functional reestablishment of females with PFP.

Delayed onset of electromyographic activity of the vastus medialis relative to the vastus lateralis may be related to physical activity levels in females with patellofemoral pain.

The aims of this study were to examine group differences in muscle activation onset of the vastus medialis (VM) in relation to the vastus lateralis (VL) and pain level during stair ascent in females with patellofemoral pain (PFP) who maintain high and moderate levels of physical activity; to determine the association between physical activity level and muscle activation onset. Forty-three females with PFP and thirty-eight pain-free females were recruited and divided into four groups based on their level of physical activity: females with PFP (n=26) and pain-free females (n=26) who practiced a moderate level of physical activity and females with PFP (n=17) and pain-free females (n=12) who practiced an intense amount of physical activity. Participants were asked to ascend a seven-step staircase and the VM and VL activation onset was determined. Females with PFP who practiced high level of physical activity demonstrated delayed onset of VM (4.06ms) compared to healthy females (-14.4ms). Conversely, females with PFP who practiced moderate level of physical activity did not present VM delay (-2.48ms) in comparison to healthy females (-9.89ms). Furthermore, physical activity significantly correlated to the muscle activation onset difference (p=0.005; R=0.60). These findings may explain why controversial results regarding VM and VL muscle activation onset have been found.

Correlação da força vertical de reação do solo e da velocidade angular do joelho de jovens e idosas durante descida de escada / Correlation between vertical ground reaction force and knee angular velocity of young and elderly individuals during stair descent

Objetivo:Correlacionar a força vertical de reação do solo e da velocidade angular do joelho de jovens e idosas durante descida de escada.Métodos:A amostra foi dividida em dois grupos: Grupo Idosas (GI; n=10) e Grupo Jovens (GJ; n=16). Foi utilizada uma escada de teste composta por sete degraus, onde uma plataforma de força estava acoplada ao quarto degrau para aquisição dos dados cinéticos e determinação do momento de contato do pé com o degrau; também foi usado um sistema de cinemetria tridimensional, com quatro câmeras infravermelhas. As voluntárias desceram os degraus de forma contínua, com velocidade e ritmo autosselecionados. Para comparação dos dados, foi utilizado o teste t Student para amostras independentes e para a correlação das variáveis, o teste de correlação de Pearson, adotando nível de significância α=0,05.Resultados:Os resultados mostraram diferença significativa para a média dos picos das velocidades angulares do joelho, com o GJ apresentando maior pico (240,7±10,5 g/s) comparado ao GI (186,4±13,2 g/s). Em relação ao pico de força vertical (Fz), o GJ obteve maior magnitude de força (1,39±0,03) comparado ao GI (1,15±0,02), apresentando diferença significativa (p=0,00). Os resultados apontaram ainda uma correlação positiva entre as variáveis (r=0,4).Conclusão:Os resultados indicam que idosas apresentam menor velocidade angular de joelho e menor força vertical durante descida de escadas comparadas a jovens, e que há correlação entre as variáveis.

Objective:To analyze the relationship between vertical ground reaction force and knee angular velocity of young and elderly persons during stair descent.Methods:The sample consisted of two groups: the Elderly Group (EG; n=10) and the Young Group (YG; n=16). A ladder test consisting of seven steps, with a force plate coupled to the fourth step to acquire kinetic data and determine the moment of foot contact with the step, was used, as well as a system of three-dimensional kinematics with four infrared cameras. The volunteers descended the stairs continuously, at a self-selected speed and pace. The Student's t-test was used for independent samples and the Pearson correlation test was used to test the correlation of the variables, with a level of significance of α=0.05.Results:The results showed a significant difference between the YG group (240.7±10.5 g/s) and the EG group (186.4±13.2 g/s) for mean peak knee angular velocity. Regarding peak vertical force (Fz), YG had a higher magnitude of force (1.39±0.03) than EG (1.15±0.02), with a significant difference between the groups (p=0.00). The results also showed a positive correlation between variables (r=0.4).Conclusion:The results indicate that elderly persons have a lower knee angular velocity and lower vertical force during stair descent than young people and that there was a correlation between the variables.