Hamstring & Calf Strain Physiotherapy · Bukit Timah, Singapore
Hamstring & Calf Strain Physiotherapy
A sudden, sharp pain at the back of the thigh or lower leg during a sprint, jump, or quick change of direction — hamstring and calf strains are among the most common acute muscle injuries in sport. Hamstring strains in particular have a genuinely high recurrence rate, and most of those reinjuries happen within the first two months of returning to sport, which is exactly what a properly staged rehab programme is designed to prevent.
Assessed and treated by Ng Hong Kai, Singapore's only dual-credentialled APA Titled Musculoskeletal Physiotherapist and tertiary-trained Exercise Scientist.
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How Muscle Strains Are Graded
Both hamstring and calf strains use the same three-grade system based on how much muscle tissue is torn. This grading — alongside where exactly the injury sits within the muscle — shapes how your rehab is staged.
Grade I — Mild
A small number of muscle fibres are torn. Some pain and tenderness, but strength and function are largely preserved.
Grade II — Moderate
A significant number of fibres are torn, with a real loss of strength and function. This is the most common grade seen in clinic for both muscle groups.
Grade III — Severe
A complete tear or rupture of the muscle, with major loss of function. Significant bruising and swelling are typical, and this grade occasionally warrants orthopaedic referral.
Hamstring Strains
The hamstrings are a group of three muscles at the back of the thigh. Most strains happen during the late swing phase of sprinting — the split second where the leg is decelerating and straightening just before the foot strikes the ground, and the hamstring is contracting forcefully while simultaneously being lengthened. This specific combination is why hamstring strains are so strongly associated with high-speed running sports, and why they have a reputation as one of the more stubborn injuries in sports medicine — recurrence rates are reported anywhere from roughly 12 to 38%, and notably, most of those reinjuries happen within the first two months after returning to sport.
What genuinely reduces the risk of reinjury, based on current evidence:
- Eccentric strength at a lengthened muscle position, specifically. Research consistently points to a deficit in strength when the hamstring is in a stretched position — not just general weakness — as a key driver of reinjury. Exercises like the Nordic hamstring exercise, which train the muscle eccentrically through a long range, directly target this, and structured eccentric protocols have shown recurrence rates as low as 8% in supervised, compliant athletes, well below the typical range.
- Trunk and pelvic control, not just the hamstring itself. At least one study found a rehab programme built around agility and trunk stabilisation outperformed a more traditional stretching-and-strengthening approach on recurrence — a reminder that hip and core control genuinely matters here, not just isolated hamstring exercises.
- Objective readiness testing before return to sport, rather than a fixed number of weeks — strength symmetry and functional testing give a far more reliable picture of whether the muscle is actually ready than the calendar does.
Calf Strains
The calf is made up of two main muscles — the gastrocnemius, which crosses both the knee and ankle, and the soleus underneath it, which crosses only the ankle. Calf strains typically happen from a sudden, forceful push-off — accelerating from a stationary position, jumping, or lunging forward — rather than the gradual lengthening mechanism behind most hamstring strains. Where exactly the strain sits matters: gastrocnemius strains (often felt as a sudden, sharp pain, sometimes described as being "hit" on the back of the leg) and soleus strains (which can feel more like a deep ache and are easier to under-recognise early on) behave a little differently and are assessed accordingly.
What the rehab approach focuses on:
- Progressive loading, not prolonged rest. As with most muscle strains, movement within a pain-tolerable range tends to support healing better than complete immobilisation, once the acute, most painful phase has settled.
- Calf strength and capacity, specifically for push-off and landing. Since the mechanism is typically a forceful contraction rather than a stretch, rebuilding the calf's capacity to tolerate that same demand — heel raises progressing to more dynamic, sport-specific loading — is central to reducing reinjury risk.
- A graded return to the specific movement that caused it — sprint starts, jumping, quick changes of direction — rather than jumping straight back into full training once walking is comfortable.
What Not to Do in the First Few Days
- Aggressive stretching immediately after the injury. Forcing a stretch on an already-torn muscle can aggravate the injury rather than help it — gentle, pain-free movement is more appropriate early on than trying to "loosen it up."
- Testing it too soon with sprinting or jumping. A muscle that feels fine walking can still fail under the much higher forces of sprinting or a sudden change of direction — this is precisely how many early reinjuries happen.
- Returning to sport once it "doesn't hurt," without objective strength testing. Pain resolving is not the same as the muscle having rebuilt the strength and capacity it needs, particularly at the lengthened positions relevant to sprinting.
How Long Does Recovery Take?
Timelines depend heavily on the grade of injury and which muscle group is involved. As a general guide:
- Grade I: Typically 1 to 3 weeks before a full, graded return to sport
- Grade II: Generally 3 to 8 weeks, depending on muscle group and how well rehab is followed
- Grade III: Often 8 to 12 weeks or longer, and occasionally requires orthopaedic input
Given the well-documented reinjury risk with hamstring strains specifically, we'd rather see you complete a properly staged programme — including objective strength testing before clearing a return to sport — than rush back on a shorter timeline and risk a second, often worse, injury. We'll give you a realistic timeline specific to your presentation at assessment.
Fees
See our full fees page, or check your insurance coverage.
Hamstring & Calf Strain FAQ
Why do hamstring strains come back so often?
Reported recurrence rates genuinely are high, typically cited between 12 and 38%, and most reinjuries happen within two months of returning to sport. The leading explanation is that the muscle remains weak specifically in its lengthened position — the exact position it's under load in during sprinting — even after pain has resolved, which is why targeted eccentric strengthening and objective testing before return to sport matter so much here.
Should I stretch a strained hamstring or calf?
Not aggressively, and not immediately after the injury — forcing a stretch on freshly torn muscle tissue can do more harm than good. Gentle, pain-free movement is appropriate early on, with more targeted flexibility and strength work introduced progressively as the injury heals, guided by an assessment rather than a generic stretching routine.
Do I need an ultrasound or MRI?
Not routinely for a straightforward strain — grade and location are usually assessed clinically. Imaging is more useful for higher-grade injuries, when the diagnosis is unclear, or to help guide a return-to-sport timeline in elite or time-critical situations.
How do I know when I'm actually ready to return to sport?
Pain resolving with walking or light jogging isn't, by itself, a reliable sign — the muscle needs to be objectively tested at higher speeds and loads before we'd clear a return, particularly for hamstring strains given the well-documented reinjury pattern. This typically includes strength testing and comparing the injured side against the uninjured one, not just how it feels.
Is a calf strain the same as Achilles tendon pain?
No — they're different structures with different mechanisms, though they sit close together. A calf strain is a sudden muscle tear, usually with a clear moment of onset during a forceful push-off. Achilles tendinopathy is a gradual, overuse-related breakdown of the tendon itself, further down toward the heel. If you're not sure which one you have, an assessment will clarify it, since the rehab approach genuinely differs.
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Get Back to Sport Without Risking a Repeat Injury
Book an assessment and get a properly staged rehab plan built to reduce your risk of reinjury, not just settle the pain.
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Our Sports Injury Physiotherapist
As Clinic Director and Chief Physiotherapist, Ng Hong Kai is dedicated to delivering care backed by strong credentials and hands-on expertise. He offers therapies that combine professional training with a genuine passion for patient well-being.
Hong Kai supports both general musculoskeletal health and sports injury rehabilitation. With a background in exercise physiology and biomechanics, he designs personalised recovery plans to help patients return to their sport stronger while reducing the risk of re-injury.
