Can some physical therapy and manual techniques generate potentially osteogenic levels of strain within mammalian bone?

Background and Purpose; Although physical therapy techniques are used to al leviate pain and stiffness in joint injuries, whether these methods are cap able of affecting bone is unknown. For example, can these techniques potent ially influence bone formation or resorption? To begin exploring this possi bility, this study investigated the ability of 4 manual techniques to gener ate levels of compressive strains that presumably can stimulate bone metabo lism. Subjects. Six 3,4 metacarpals from three 3-year-old Merino ewes were used. Methods. A rosette strain gauge was implanted onto the dorsomedial co rtex of each ovine 3,4 metacarpal. Four different manual procedures were ap plied on 2 occasions on each metacarpal in vivo and ex vivo. Mean peak prin cipal compressive strains were calculated for each technique. Results. Leve red bending produced greater mean peak compressive strains than almost all other manual procedures tested in vivo or ex vivo. Conclusion and Discussio n. Manual levered bending created levels of compressive strain similar in m agnitude to those created by mechanical devices used in previous animal exp eriments to induce new bone formation (osteogenesis). This animal model app ears to be suitable for investigating the effects of manually applied proce dures on bone and may establish whether manual techniques can stimulate bon e formation. [Wilson AW, Davies HMS, Edwards GA, Grills BL. Can some physic al therapy and manual techniques generate potentially osteogenic levels of strain within mammalian bone?