Question: When was the retired Indian track and field athlete coached by O. M. Nambiar born? 

Context articles: Angel Mary Joseph
Mercy Kuttan
Mayookha Johny
P. T. Usha
Joseph Abraham
Murali Kuttan
Santhi Soundarajan
O. M. Nambiar
K. M. Binu
Anil Singh (athlete)

Angel Mary Joseph (born 24 September 1953) is a retired Indian track and field athlete.
 She specialized in 100 metres hurdles, Long Jump, Pentathlon, and once held national records in all the three and high jump and heptathlon.
 At the 1978 Asian Games in Tehran, she won silver medals in long jump and pentathlon.
 She also represented Karnataka and Railways playing basketball in the National Championships.
Mercy Kuttan (born 1 January 1960) is a former Indian track and field athlete.
 She was the first Indian woman longjumper to cross six meters.
 In 1989, Mercy received Arjuna Award for her contribution to the Indian athletics.
Mayookha Johny (born 9 April 1988) is an Indian track and field athlete from Kerala who specialises in long jump and triple jump.
 She holds the current Indian National record for triple jump with a mark of 14.11 m (46 ft floor(((14.11)*3.28084)−(floor((14.11)*3.28084)) *12) in) .
 She is the first Indian woman to cross the fourteen-metre mark.
Pilavullakandi Thekkeparambil Usha (born 27 June 1964), popularly known as P. T. Usha, is a retired Indian track and field athlete.
 She has been associated with Indian athletics since 1979.
 She is often called the "queen of Indian track and field".
 She is nicknamed as the Payyoli Express.
 Currently she runs the Usha School of Athletics at Koyilandy in Kerala.
Joseph Ganapathiplackal Abraham (born 11 September 1981) is an Indian track and field athlete from Kerala.
 He holds the current 400 metre hurdles national record of 49.51 seconds set during the 2007 World Championships in Athletics in Osaka on 26 August 2007.
 At Osaka, Abraham became the first Indian male athlete to clear the opening round of an event in the World Athletics Championships when he reached the 400m hurdles semifinals.
 He also won the 400m hurdles gold medal at 2010 Guangzhou Asian Games.
Murali Kuttan (Malayalam: മുരളി കുട്ടന്‍ ) (1953?
 – 19 December 2010) was an Indian track and field athlete who represented the country as a sprinter on several occasions.
 He won the 400 metres gold in the Indo-Russian athletic meet in 1978.
 In the same year, he also won the bronze in the 400 metres at the Asian Games in Bangkok.
 He was married to former olympian athlete Mercy Kuttan.
Santhi Soundarajan (also spelled "Shanthi Soundararajan",Tamil: சாந்தி சௌந்திரராஜன் , born April 1981) is an Indian track and field athlete.
 She is the winner of 12 international medals for India and around 50 medals for her home state of Tamil Nadu.
 Shanthi Soundarajan is the first Tamil woman to win a medal at the Asian Games.
 She competes in middle distance track events.
 She was stripped of a silver medal won at the 2006 Asian Games after failing a sex verification test which disputed her eligibility to participate in the women's competition.
O. M. Nambiar (born 1932) is an Indian athletics coach who was awarded Dronacharya award in 1985.
 He coached the well known Indian athlete P. T. Usha.
 He hails from Kerala state.
Kalayathumkuzhi Mathews Binu (born 20 December 1980) is an Indian track and field athlete from Kerala who specializes in 400 metres and 800 metres.
 He holds the current 400 metres national record of 45.48 s set at the 2004 Athens Olympics on 20 August 2004.
 He broke the 44-year-old Olympics mark (by an Indian) held by Milkha Singh who set an Indian National Record with a timing of 45.73 s at the 1960 Rome Olympics.
 He and his elder sister K. M. Beenamol made history when they became the first Indian siblings to win medals in a major international competition.
 They won medals at the Busan Asian Games (2002).
 While Binu won the men's 800 metres silver, his sister won the gold medal in the women's event.
 Binu received the Arjuna Award for the year 2006 for his achievements in the Indian athletics.
Anil Kumar Singh (born 4 March, 1985) is an Indian track and field athlete from Haryana who specializes in javelin throw.
 He is the first Indian athlete to breach the 80-metre barrier in a competition.
 Anil Singh holds the current Indian National record of 80.72 metre set at the Asian All Stars athletics championships held in Bhopal on 18 September 2008.
 He replaced Satbir Singh's decade-old record of 79.68 metres, registered in Kolkata in October 1998.