How to treat my back pain and numbness in leg?

Spunds like you have injured your self quite serious. Neural signs(pins and needles) like you describe can be a sign of neural irritation.Best recommendation would be see a health care professional about his matter, whether GP, physiotherapist or chiropractor. They will be able to examine you to determine the best care for you. Ypurbwould
most likely require some manual therapy to restore motion and minimiZe nerve irritation. Than begin a rehabilitation program to restore function and strength to your spine

Sorry for your unfortunate situation.  While some health problems can be adequately self-managed, this is the sort of problem that does need the assistance of skilled health care practitioner/s for proper management otherwise the back/leg symptoms can become permanent and/or quite disabling.  As a spine-related disorder, the chiropractor would follow a step-by-step process in order to help you get the best results.  Once all relevant case information has been gathered, a clinical care and advice strategy can be chosen that best matches the specific problem.  While exercises are often key ingredients in the management of back and leg symptoms, it is important that the best ones are prescribed for your individual case situation; the wrong ones can worsen your pain and overall problem. 
 
Management steps include:
 
1.     A thorough clinical assessment with the goal of identifying the underlying cause/mechanism of your particular symptoms.  In addition to a detailed patient history, a combination of structure, function, physical and neurological tests are performed which may include the taking of a set of x-rays or other imaging/laboratory tests.  It is also important that the chiropractor rules out any serious problems, before they can assist any further.  Based on the brief information you have provided about the nature of your symptoms and how they came about, I wouldn’t be at all surprised if you have sustained a tear in the back part of a lower back disc on the right side.  Since there is not much room next to where a disc typically bulges, protrudes or leaks in a situation like this, nearby blood vessels and delicate nerve structures can become irritated/compressed thereby causing pain, numbness along with pins and needles as you describe.
 
2.     If it is confirmed that your symptoms are not likely caused by an infection, cancer, fracture or other condition that would require management coordinated by your GP, the chiropractor can formulate an effective, safe customised clinical care and advice strategy for most types of disc-related problems.  It is important that your chiropractor and GP have a good working relationship together to help you, so that appropriate treatment is coordinated. 
 
3.     The chiropractor will need to fully explain the nature of your condition, recommendations and gain an understanding of your health goals.  You can then make an informed decision and provide consent to proceed.
 
4.     A trial period of specific care and customised advice can then commence.  This is aimed at helping to relieve pain and optimise the healing process.  In addition to the gentle clinical procedures provided by the chiropractor and your self-management strategies, you’ll probably need to see your GP for some additional pain-relief assistance.  Over-the-counter pain medication such as paracetamol may not provide enough relief.  Optimising the healing process often focuses on:
· careful and selective movement of the lower back and leg in particular directions that help reduce the back and leg symptoms.
· improving mobility of the mid back and sometimes hip/s.
· improving stability and coordination of the lower trunk. For more information, see my response to the question: Is a strong core essential for injury prevention? 
 
5.     Your progress should be closely monitored, along with periodic case reassessments.  If there has been satisfactory progress after the initial trial period but your goals have not yet been achieved, an additional period of clinical care and advice can be provided.  Once your goals have been achieved, the aim should be that you have become equipped to be able to self manage your clinical problem as much as possible.  Unfortunately, it is common that these types of problems don’t fully resolve, so it is important that you partner with your rehabilitation/sports chiropractor to learn the necessary skills for optimum self-management.
 
If your condition worsens at any stage or fails to respond sufficiently after a trial of regular treatment over a 4 to 6 week timeframe, current clinical guidelines suggest that advanced diagnostic imaging, such as magnetic resonance imaging (MRI) if not done so already, should be performed.  This may also result in referral to a neurosurgeon or orthopaedic surgeon for a management opinion. 
 
Hope that helps.  Best wishes, Peter

Most likely you have a disc injury causing irritation to the nerve that supplies that part of the leg, typically the sciatic nerve.Sounds like your physio wants to further investigate your lumbar spine, specifically why your leg and hip pain has not resolved. A MRI would be the best type of imaging for these type of conditions.