Muscle Strength and Development

Transcription

1 Muscle Strength and Development Part 2: Muscle strengthening in children and adolescents with cerebral palsy Methods: Muscle Strength (Hand-Held Dynamometer) boys girls Beenakker EA, van der Hoeven JH, Fock JM, Maurits NM. Reference values of maximum isometric muscle force obtained in 270 children aged 4-16 years by hand-held dynamometry. Neuromuscul Disord. 2001;11(5): Wind EA MSc Thesis Utrecht University 2007 Conclusion Muscle Strength Increase with age/body weight/ body height Difference between boys and girls at 12 years of age Girls are plateauing earlier than boys s Isometric resistance based methods: MMT HHD Isokinetic dynamometry: Computercontrolled equipment Alternative: Repetition maximum 1

2 Percentage of predicted values 30-sec Repetition Maximum Lateral Step-up Test Sit-to-Stand Attain stand through half kneel Intertester reliability HHD Break-test ICC Make-test ICC sec RM ICC Conclusion tests The reliability of the HHD is questionable. Ways to improve measurement: Use same examiner Use make-method The reliability of the 30-sec RM is good. Use standardized protocol Can be used for children with CP (classified at GMFCS level I or II) Useful measures Muscle strength in children with CP Aerobic capacity FITNESS Muscle strength 30-sec RM HHD (make method) GMFCS I GMFCS II GMFCS III Anaerobic capacity 2

3 ILOP RECT GLUT ABD ADD HAMS QU 90 QU 30 PF (E) PF (F) DF (E) DF (F) ILOP RECT GLUT ABD ADD HAMS QU 90 QU 30 PF (E) PF (F) DF (E) DF (F) strength strength Muscle strength lower Damiano et al 1998 Conclusion controle hemiplegie diplegie non dominant side controle dominant side hemiplegie diplegie Testuitslagen muscle group muscle group Low muscle strength High muscle strength Muscle Strength Training Children Youth Resistance Training Potential Benefits Participation in a youth resistance training program can influence many health- and fitness-related measures. Potential Risks and Concerns Appropriately prescribed youth resistance training programs are safe. Program Design Considerations for Children Consider quality of instruction and rate of progression. Focus on skill improvement, personal successes, and having fun. Children Children Youth Resistance Training Guidelines Each child should understand the benefits and risks associated with resistance training. Competent and caring professionals should supervise training sessions. The exercise environment should be safe and free of hazards. All equipment should be in good repair and properly sized to fit each child. Dynamic warm-up exercises should be performed before resistance training. Youth Resistance Training Guidelines (continued) Carefully monitor each child's tolerance to the exercise stress. Begin with light loads. Increase the resistance gradually (e.g., 5% to 10%) as strength improves. Advanced multi-joint exercises may be incorporated into the program if appropriate loads are used and the focus remains on proper form. Two or three nonconsecutive training sessions per week are recommended. The resistance training program should be systematically varied throughout the year. Children should be encouraged to drink plenty of water before, during, and after exercise. 3

4 Strength training in children with Cerebral Palsy Different training modalities - Progressive Resistance Exercise - Electro stimulation What works? Effect of resistance training on MUSCLE STRENGTH Lower Upper Electro stimulation Effect of resistance training on GMFM Lower Electro stimulation N= 119 Muscle strengthening is not effective in children and adolescents with cerebral palsy: A systematic review. Scianni A, Butler JM et al. Aust J Physiother 2009; p81-87 N= 99 Muscle strengthening is not effective in children and adolescents with cerebral palsy: A systematic review. Scianni A, Butler JM et al. Aust J Physiother 2009; p81-87 Effect training on WALKING SPEED Discussion Different methods in 1 review / meta-analysis Lower Electro stimulation If there is no effect on muscle strength or activity level is training still worthwhile? N= 63 Muscle strengthening is not effective in children and adolescents with cerebral palsy: A systematic review. Scianni A, Butler JM et al. Aust J Physiother 2009; p

5 Effect of resistance training for the lower in children and adolscents CP Dodd et al Liao et al Lee et al Scholtes et al Progressive resistance exercise is most often used. Total Is this method effective? N= 105 Verschuren et al. PT journal 2011 Important ingredients according to the Warming-up (5-10 minutes) Type of exercise Intensity Frequency (2-3 times a week) Duration of the programme Progression during the programme Age of children Type Type of exercises Dodd: multi-joint exercises (heel raises, half squats and stepups) multi-joint exercises Single-joint and Liao: multi-joint exercises (sit-to-stand) loaded (using weight vest) Lee: multi-joint exercises (squat to stand, lateral step up, stair up and down) loaded (using weight cuffs), Scholtes: multi-joint exercises (leg press) and loaded (using a weight vest) Type of exercises: mostly functional based What is the trainingseffect on the muscle groups that were targeted? Muscle groups targeted in 4 RCT s: Knee-extensors -extensors Plantar flexors 5

6 Result on muscle group level. Intensity of the programme Study Ankle plantar flexors Knee extensors Knee flexors extensors flexors abductors adductors Dodd et al Lee et al Liao et al. - Scholtes et al Intensity Dodd: 3 sets of 8-12 repetitions to fatigue Liao: 1 set of 10 repetitions at 20% 1RM 1 set of repetitions until fatigue at 50% 1RM 1 set of 10 repetitions at 20% 1RM Lee: 2 sets of 10 repetitions (low load and no progression) Scholtes: 3 sets of 8 RM Only 2 of the 4 studies are in line with the 1-3 sets of 6-15 repetitions of 50-85% RM Be aware of compensation during exercises! Duration of the programme Duration Dodd: 6 weeks Liao: 6 weeks Lee: 5 weeks Scholtes: 6 weeks (12 week program) 8-20 weeks Effect of resistance training of the lower in typically developing children No study is in line with the Significant relation between duration and trainingseffect: Behringer et al. Pediatrics Oct 25, 2010 N= 1728 Age of training Age Dodd: mean 13.1, SD 3.1, range 8-18 years of age Liao: mean 7.4, SD 1.6, range 5-12 years of age Lee: mean 6.3, SD 2.5, range 4-12 years of age Scholtes: mean 10.5, SD 1.1, range 6-13 years of age Age 7 and onwards Longer interventions with sufficient intensity, for example, 12 weeks, may be needed to see significant or meaningful improvements in strength. In 3 out of the 4 studies included children younger than the recommended 7 years of age. 6

7 Single-joint resistance training may be more effective for very weak muscles or for children or adolescents who tend to compensate when performing multi-joint exercises, or at the beginning of the training. Depending on the complexity of the exercise and the level of motor impairment, children and adolescents with CP may need more than 1 minute of rest between bouts (perhaps up to 3 minutes). Since strength training, as it is traditionally done, requires maximal effort and can include somewhat complicated activities, older children and adolescents, over 7 years old, are perhaps better suited to this intervention that younger children. Children or adolescents with more impairment might also benefit from strength training, but if it is difficult for them to contract voluntarily, methods such as electrical stimulation, mental imagery and biofeedback could be helpful. 7