Effect of Plyometric Exercises in Premenopausal Women
Condition: Premenopausal Women
Study type: Interventional

Summary: 
      It was aimed to examine the effects of plyometric exercises on muscle strength in this study.
      26 premenopausal women assigned to one of the three groups: Control Group (n=8), Plyometric
      Exercise Group (n=10) and Isokinetic Exercise Group (n=8). Muscle strength assessments,
      depression and anxiety inventories were performed baseline and after 6 weeks.
    

Detailed description: 
      Depending on various factors, bone mass begins to decrease with aging and this may lead to
      the osteoporosis. Physical activity and regular exercise provides an increase in bone mineral
      density (BMD). It is mentioned that there are relationships between muscle strength and BMD
      and also muscle strength has positive effects on BMD. In the literature it is showed that
      postmenopausal women with weaker trunk muscle strength could have risk of osteoporosis.

      Plyometric exercises are used to increase muscle strength. Physiological basis of plyometric
      exercise consist of stretch-shortening cycle and thus it is effective in increasing the
      force. At the same time, plyometric exercises have positive effects on BMD because of weight
      bearing exercises.

      The aim of this study was to investigate the effects of plyometric exercises on hip and trunk
      muscle strength in premenopausal women.

      Participants and Study Design: Twenty six sedentary premenopausal women aged 35-50 years
      participated this study. Participants were assigned into three groups: Plyometric Exercise
      Group (PG; n=10), Isokinetic Exercise Group (IG; n=8), Control Group (CG; n=8). Participants
      were informed about the procedures of the study and signed a written voluntary consent form
      in accordance with the Declaration of Helsinki. The study protocol was approved by the
      Ethical Committee of the Istanbul University Medical Faculty. Measurements and training
      sessions were performed in the Istanbul University Medical Faculty Sport Medicine
      Department's Laboratory.

      Measurements: Muscle strength was determined by using a Cybex Norm isokinetic dynamometer
      (Cybex Humac Norm, USA). Range of motion was set from 10 degree extension to 40 degree
      flexion. Isokinetic concentric contraction strength was measured at angular velocity of 60
      degree per second and 90 degree per second. Subjects performed 3 trials trunk flexion and
      extension contractions at minimal exertion and 4 test repetitions at maximal trunk flexion
      and extension.

      The hip abduction adduction isokinetic testing was performed in side lying position. Hip
      muscle strength was measured at angular velocity of 30 degree per second. Range of motion was
      set from 10 degree adduction to 40 degree abduction. Subjects performed 4 trials at minimal
      exertion and 4 test repetitions. Dominant leg values were analyzed for hip. All subjects
      performed warm-up and stretching exercises before testing.

      Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI) were used to asses
      depression and anxiety conditions.

      Interventions: The training sessions were performed three days a week for six weeks. All
      exercise sessions were supervised by a physiotherapist.

      Each session was consisted of warm-up, plyometric exercises and cool-down periods in PG. The
      warm-up and cool-down periods were performed by walking on the treadmill and lower extremity
      stretching exercises. The plyometric exercise training period involved vertical jumping,
      forward and back jumping and lateral jumping. After fifth session the number of repetitions
      were increased depending of toleration of participants. After tenth session step bench
      jumping exercise and after fifteenth session diagonal jumping exercise were added and study
      was completed in eighteen session.

      In IG, isokinetic exercises were performed by using a Cybex Norm isokinetic dynamometer with
      an incorporated trunk flexion/extension unit in a standing position. Range of motion was set
      from 10 degree extension to 40 degree flexion. Each session was consisted warm-up, isokinetic
      exercises and cool-down periods. Warm-up and cool-down periods were consisted trunk exercise
      and stretching. Isokinetic exercises were performed 7 repetitions at angular velocity of 90
      degree per second , 6 repetitions at angular velocity of 75 degree per second and 5
      repetitions at angular velocity of 60 degree per second.

      Participants in CG were assessed baseline and at sixth week.
    

Intervention name(s): Exercise
Intervention type(s): Other
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Plyometric exercise; Isokinetic; Muscle strength; Premenopause