The loss of physical activity after a spinal cord injury results in musculoskeletal deterioration and metabolic dysfunction. Rehabilitation often overlooks the importance of physical activity in the paralyzed limbs for systemic metabolic health. There is a need for safe, feasible exercise interventions to increase physical activity levels in the paralyzed limbs of people with chronic paralysis that have severe musculoskeletal loss. The goal of this work is to 1) develop a gene expression signature after a single dose and long term training using a high force exercise in people with an acute spinal cord injury; 2) develop a novel low force exercise intervention using electrical muscle stimulation to limit force production and increase routine physical activity for chronically paralyzed human skeletal muscle; 3) determine the gene expression signature after a single dose of this novel low force exercise in people with long term paralysis; 4) develop a dose estimate of this low force exercise needed to initiate a phenotype transformation of chronically paralyzed skeletal muscle. The major findings of this research are 1) a single dose of high force exercise increases the expression of key regulatory genes needed for the transformation of paralyzed skeletal muscle observed after long term training; 2) our novel low force exercise intervention challenges chronically paralyzed muscle but not non-paralyzed muscle; 3) a single dose of low force exercise increases the expression of key regulatory genes needed to improve skeletal muscle health; 4) a dose of at least 4 days per week of our low force exercise is needed to initiate a phenotype transformation of chronically paralyzed skeletal muscle. Together, this work supports the use of a low force exercise intervention for people with long term spinal cord injury and establish the need for future work assessing effects of our low force exercise on the systemic health and quality of life of people with long term spinal cord injury.

Darbo objektas: skirtingų raumens elektrinės stimuliacijos metodų poveikis kelio sąnario judesių amplitudei, raumenų jėgai ir skausmui po priekinio kryžminio raiščio rekonstrukcinės operacijos. Tyrimo tikslas: nustatyti kineziterapijos ir skirtingų raumens elektrinės stimuliacijos metodų efektyvumą kelio sąnario judesių amplitudei, raumenų jėgai ir skausmui po priekinio kryžminio raiščio rekonstrukcinės operacijos. Tyrimo uždaviniai: 1. Įvertinti kineziterapijos ir pasyvios raumens elektrinės stimuliacijos poveikį kelio sąnario judesių amplitudei, raumenų jėgai ir skausmui. 2. Įvertinti kineziterapijos ir aktyvios raumens elektrinės stimuliacijos poveikį kelio sąnario judesių amplitudei, raumenų jėgai ir skausmui. 3. Palyginti kineziterapijos ir skirtingų raumens elektrinės stimuliacijos metodų poveikį kelio sąnario judesių amplitudei, raumenų jėgai ir skausmui. Tyrimo hipotezė: Manome, kad kineziterapija ir aktyvi raumens elektrinė stimuliacija, labiau padidins šlaunies raumenų jėgą, kelio sąnario judesių amplitudę bei sumažins skausmą kelio sąnaryje vaikštant, lyginant su pasyvios elektrinės stimuliacijos taikymu pacientams po priekinio kryžminio raiščio rekonstrukcinės operacijos. Išvados: 1. Pacientams, kuriems taikyta kineziterapija ir pasyvi raumens elektrinė stimuliacija, statistiškai reikšmingai (p<0,05) padidėjo kelio sąnario lenkimo ir tiesimo amplitudė, blauzdą lenkiančių ir tiesiančių raumenų jėga, o skausmas vaikštant sumažėjo. 2. Pacientams, kuriems... [toliau žr. visą tekstą] / The object: Different muscle electrical stimulation methods for knee joint range of motion, muscle strength and pain after anterior cruciate ligament reconstructive surgery. The aim of the research: to determine the effectiveness of physical therapy and different muscles electrical stimulation methods for knee joint range of motion, muscle strength and pain after anterior cruciate ligament reconstructive surgery. The task of the research: 1. To evaluate the effectiveness of physical therapy and passive muscle electrical stimulation for knee joint range of motion, muscle strength and pain. 2. To evaluate the effectiveness of physical therapy and active muscle electrical stimulation for knee joint range of motion, muscle strength and pain. 3. Compare the effectiveness of physical therapy and different muscle electrical stimulation methods for the range of motion of the knee joint, muscle strength and pain, between control and experimental groups. Hypothesis: we believe that physical therapy and active muscle electrical stimulation will increase thigh muscle strength, the range of motion of the knee and reduce pain in the knee while walking, compared with a passive muscle electrical stimulation in patients after anterior cruciate ligament reconstructive surgery. Conclusions: 1. Patients who apply physical therapy and passive muscle electrical stimulation, statistically significantly increased (p<0,05) the flexion and extention of the knee, strenght of the muscles that bend... [to full text]

hjlahgih / Thesis (DPhil (Human Movement Science))--University of Pretoria, 2005. / Biokinetics, Sport and Leisure Sciences / unrestricted

Functional recovery following peripheral nerve injuries is poor due to muscle atrophy and fibrosis being major contributing factors. Electrical muscle stimulation has been used for decades in some capacity to treat denervation related muscular changes. The research presented in this thesis explores a new stimulation paradigm and its effects on short and long term muscle denervation. The first part of this work describes the new stimulation paradigm and the design and development of the stimulator used to deliver this paradigm. The paradigm involved daily 1-hour stimulation sessions featuring 600 contractions at high stimulus frequencies (100 Hz) and low pulse durations (200 μs). To test the device and paradigm, a pilot study involving muscle stimulation throughout a one month period of denervation in rat lower limb muscles was carried out. The results showed that this short but intense stimulus session significantly reduced the rate of muscle atrophy compared to animals that did not receive stimulation. Furthermore, muscle weight and consequently muscle force were also significantly greater. The stimulus paradigm was then used to investigate muscle that was denervated and immediately repaired. Ideally, immediate nerve repair following nerve injuries produces the best outcome. One month of electrical muscle stimulation following nerve repair enhanced this outcome through significant increases in muscle weight and force. Additionally, contrary to many previous studies, the stimulus paradigm had no negative effects on reinnervation. Taken together, electrical muscle stimulation can provide significant improvements over the best case scenario of immediate nerve repair. The third part of this work investigated the use of chronic electrical muscle stimulation throughout three months of denervation and the impact on reinnervation. Results showed that reinnervation in chronically stimulated animals were no different than animals that were denervated and immediately repaired. The last part of this work combined the use of electrical muscle stimulation with sensory protection in chronically denervated muscle. Sensory protection involves suturing a sensory nerve to protect a muscle during denervation and was shown in previous studies to reduce muscle atrophy, preserve muscle spindles and the structure of the distal nerve stump. The results showed significantly greater muscle weights and force in the combined treatment compared to the individual treatments alone. Reinnervation in these animals was as good as those that were immediately repaired. This suggests that contractile support combined with sensory protection may provide superior functional outcomes in chronically denervated muscle. The findings presented in this thesis provide new evidence for the use of short duration daily electrical muscle stimulation immediately following nerve repair or throughout long term denervation. Evidence for a new therapy, muscle stimulation with sensory protection, is also presented and shown to provide superior functional outcomes compared to either therapy alone. The contributions made in this body of work may provide clinicians with evidence to pursue clinical use of the outlined strategies and ultimately help patients optimally recover from peripheral nerve injuries. / Doctor of Philosophy (PhD)