McCall has assembled an extensive list of studies, grouped by condition, providing evidence of varying quality for "117 Health Conditions Helped by Yoga"; he notes the "irony" that "in yoga therapy, we don't treat medical conditions per se. We treat individuals." The various types of claim, and the evidence for them, are discussed below. Types of activity Remedial yoga The International Association of Yoga Therapists offers a definition of yoga therapy that can encompass a wide range of activities and practices, calling it "the process of empowering individuals to progress toward improved health and well-being through the application of the teachings and practices of Yoga". The history of remedial yoga goes back to the pioneers of modern yoga, Krishnamacharya and Iyengar. Iyengar was sickly as a child, and yoga with his brother-in-law Krishnamacharya improved his health; it had also helped his daughter Geeta, so his response to his students' health issues, in Newcombe's view, "was an intense and personal one." In effect Iyengar was treating "remedial yoga" as analogous to Henrik Ling's medical gymnastics. As early as 1940, Iyengar was using yoga as a therapy for common conditions such as sinus problems, backache, and fatigue. Iyengar was willing to push people through pain "to [show] them new possibilities." In the 1960s, he trained a few people such as Diana Clifton and Silva Mehta to deliver this remedial yoga; particular asanas were used for different conditions, and non-remedial Iyengar Yoga teachers were taught to tell students that ordinary classes were not suitable for "serious health issues". Mehta taught a remedial yoga class in the Iyengar Yoga Institute in Maida Vale from its opening in 1984; she contributed "Remedial Programs" for conditions such as arthritis, backache, knee cartilage problems, pregnancy, sciatica, scoliosis and varicose veins in the Mehtas' 1990 book Yoga the Iyengar Way. However, Iyengar was deferential to Western medicine and its assessments, so in Newcombe's view Iyengar Yoga is "positioned as complementary to standard medical treatment rather than as an alternative". Newcombe argues that in Britain, yoga "largely avoided overt conflict with the medical profession by simultaneously professionalising with educational qualifications and deferring to medical expertise." After Richard Hittleman's Yoga for Health series on ITV from 1971 to 1974, the series producer Howard Kent founded a charity, the Yoga for Health Foundation, to "Research into the therapeutic benefits to be obtained by the practice of yoga"; residential courses began in