Upward squatting in individuals with and without patellofemoral pain syndrome: a biomechanical study.
J Strength Cond Res
; 25(5): 1437-46, 2011 May.
Article
em En
| MEDLINE
| ID: mdl-21273914
The purpose of the study was to test the hypothesis on whether individuals with patellofemoral pain syndrome (PFPS) try to avoid knee position during upward squatting so as not to aggravate this syndrome. Also, we tested whether PFPS would generate changes in the kinetic and electromyographic (EMG) strategies used to perform this task. Eight healthy subjects and 8 subjects with PFPS, but without a history of pain for at least 30 days, took part in the experiment. They were asked to perform upward squatting with knees initially flexed at 60° (very flexed) until reaching an upright position. Angle, velocity, and acceleration (kinematic) were reconstructed for knee and ankle joints. The torques at these joints were calculated using inverse dynamics, taking into account anthropometric and inertial characteristics of each subject, including records from force data. Only activities of major muscles were recorded. The kinetic and EMG profiles were quantified during acceleration and deceleration phases of the upward squatting. Both healthy and PFPS subjects used the same kinetic and EMG strategies to perform the upward squatting, even though the magnitude of the muscle activities were decreased for the latter group. Compared to the control group, the PFPS subjects presented larger joint ankle torques and smaller knee joint torques. However, the subjects avoided keeping their knees very flexed at the initial position. Group differences in the kinetic and EMG strategies can be explained by differences in the initial position, suggesting a protective strategy used by subjects with PFPS. Therefore, for these subjects, coaches and therapists should avoid using this exercise when the knee is required to move above 40° flexion.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Postura
/
Amplitude de Movimento Articular
/
Síndrome da Dor Patelofemoral
/
Teste de Esforço
Tipo de estudo:
Observational_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Strength Cond Res
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos